Standards

GOST 22033-76 is an interstate standard titled “Studs with Stud End Length 1d and Nominal Thread Diameters from 2 to 5 mm. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to one nominal thread diameter (1d), intended for connecting parts with threaded holes, with a limited range of thread diameters (2-5 mm). The standard largely repeats the provisions of GOST 22038-76 but applies to smaller sizes.

Main Provisions:

Application Area:

• Instrument engineering: connecting small-sized parts requiring a limited depth of stud engagement into the threaded hole.
• Precision mechanics: fastening elements in precision mechanisms.
• In other industries where small threaded connections with studs and limited engagement depth are required.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to one nominal thread diameter (1d).
• Thread diameter (d): from 2 mm (M2) to 5 mm (M5). Important: the range is limited!.
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to the nominal thread diameter (d). For example, for M3 – l1=3 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22033-76 standard. The length of the stud end, which must be exactly equal to the thread diameter, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 22038-76 is an interstate standard titled “Studs with Stud End Length 1d. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to one nominal thread diameter (1d), intended for connecting parts with threaded holes. The standard applies to studs with a thread diameter from 6 to 48 mm. The accuracy class for studs according to this standard is not regulated, but normal accuracy is implied.

Main Provisions:

Application Area:

• Mechanical engineering: connecting parts requiring a limited depth of stud engagement into the threaded hole.
• Instrument engineering: fastening elements in instruments and equipment.
• In various industries where threaded connections with studs and limited engagement depth are used.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to one nominal thread diameter (1d).
• Thread diameter (d): from 6 mm (M6) to 48 mm (M48).
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to the nominal thread diameter (d). For example, for M10 – l1=10 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22038-76 standard. The length of the stud end, which must be exactly equal to the thread diameter, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 22042-76 is an interstate standard titled “Studs with Stud End Length 2.5d. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to 2.5 times the nominal thread diameter (2.5d), intended for connecting parts with threaded holes. The standard applies to studs with a thread diameter from 6 to 48 mm.

Main Provisions:

Application Area:

• Heavy machinery: connections requiring maximum strength and reliability, operating in extreme conditions.
• Shipbuilding: connections exposed to the marine environment.
• Energy industry: connections of nuclear power plant equipment.
• In any industry where stud connections are used and extremely high strength is required.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to 2.5 times the nominal thread diameter (2.5d).
• Thread diameter (d): from 6 mm (M6) to 48 mm (M48).
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to 2.5 times the nominal thread diameter (2.5d). For example, for M10 – l1=25 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22042-76 standard. The length of the stud end, which must be exactly equal to 2.5 thread diameters, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 22041-76 is an interstate standard titled “Studs with Stud End Length 2d. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to two nominal thread diameters (2d), intended for connecting parts with threaded holes. The standard applies to studs with a thread diameter from 6 to 48 mm.

Main Provisions:

Application Area:

• Mechanical engineering: connecting parts that require maximum reliability of the threaded connection, and where it is necessary to ensure the greatest stud engagement length.
• Instrument engineering: fastening elements in instruments and equipment.
• In various industries where high strength of the threaded connection is required.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to two nominal thread diameters (2d).
• Thread diameter (d): from 6 mm (M6) to 48 mm (M48).
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to two nominal thread diameters (2d). For example, for M10 – l1=20 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22041-76 standard. The length of the stud end, which must be exactly equal to 2 thread diameters, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 22040-76 is an interstate standard titled “Studs with Stud End Length 1.5d. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to 1.5 times the nominal thread diameter (1.5d), intended for connecting parts with threaded holes. The standard applies to studs with a thread diameter from 6 to 48 mm.

Main Provisions:

Application Area:

• Mechanical engineering: connecting parts where it is necessary to ensure the maximum reliability of the threaded connection, with the possibility of screwing to a greater depth than GOST 22039-76.
• Instrument engineering: fastening elements in instruments and equipment.
• In various industries where threaded stud connections are used, and the strength of the connection is important.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to 1.5 times the nominal thread diameter (1.5d).
• Thread diameter (d): from 6 mm (M6) to 48 mm (M48).
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to 1.5 times the nominal thread diameter (1.5d). For example, for M10 – l1=15 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22040-76 standard. The length of the stud end, which must be exactly equal to 1.5 times the thread diameter, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 22039-76 is an interstate standard titled “Studs with Stud End Length 1.25d. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to 1.25 times the nominal thread diameter (1.25d), intended for connecting parts with threaded holes. The standard applies to studs with a thread diameter from 6 to 48 mm.

Main Provisions:

Application Area:

• Mechanical engineering: connecting parts that require a reliable threaded connection and allow for greater engagement depth than GOST 22038-76 (1d).
• Instrument engineering: fastening elements in instruments and equipment.
• In various industries where threaded stud connections are used.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to 1.25 times the nominal thread diameter (1.25d).
• Thread diameter (d): from 6 mm (M6) to 48 mm (M48).
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to 1.25 times the nominal thread diameter (1.25d). For example, for M10 – l1=12.5 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22039-76 standard. The length of the stud end, which must be exactly equal to 1.25 times the thread diameter, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 22038-76 is an interstate standard titled “Studs with Stud End Length 1d. Construction and Dimensions.” It establishes the construction and dimensions of studs with a stud end length equal to one nominal thread diameter (1d), intended for connecting parts with threaded holes. The standard applies to studs with a thread diameter from 6 to 48 mm.

Main Provisions:

Application Area:

• Mechanical engineering: connecting parts requiring a limited depth of stud engagement into the threaded hole.
• Instrument engineering: fastening elements in instruments and equipment.
• In various industries where threaded connections with studs and limited engagement depth are used.

Main Technical Characteristics:

• Fastener type: stud (rod with thread on both ends).
• End design: with stud end.
• Stud end length: equal to one nominal thread diameter (1d).
• Thread diameter (d): from 6 mm (M6) to 48 mm (M48).
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine pitch).
• Stud length (l): depends on the thickness of the parts to be joined and is selected from a range of preferred lengths established by the standard.
• Stud end length (l1): equal to the nominal thread diameter (d). For example, for M10 – l1=10 mm.
• Threaded length (l2): the length of the threaded portion onto which the nut is screwed. Determined by subtracting l1 from the total length (l).
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5.8, 8.8, 10.9, 12.9 (for steel studs).
• Coatings: studs may have various coatings for corrosion protection (zinc, cadmium, etc.).

Main Requirements:

• Construction and dimensions: the stud must comply with the requirements for dimensions and shape specified in the GOST 22038-76 standard. The length of the stud end, which must be exactly equal to the thread diameter, is particularly important.
• Material: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs and defects, and comply with the requirements of metric thread standards.
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform and provide corrosion protection.
• Marking: must contain information about the strength class (for steel studs) and the manufacturer’s trademark.

GOST 19281-89 is an interstate standard titled “Rolled Products Made of High-Strength Steel. General Technical Conditions.” It defines general technical requirements for hot-rolled and forged products made of high-strength and ultra-high-strength steels (sheet, strip, wide-flange, bar, and shaped), intended for the manufacture of welded, riveted, or bolted metal structures and general-purpose parts operating under static and dynamic loads.

Main Provisions:

Application Area:

• Construction: Load-bearing structures of buildings and structures, bridges, overpasses, towers.
• Mechanical engineering: Manufacture of frames, housings, parts of machines and mechanisms operating under high loads.
• Shipbuilding: Ship hulls.
• Oil and gas industry: High-pressure pipelines, tanks, offshore platforms.
• Transport engineering: Wagons, locomotives, trucks.

Types of Rolled Products:

• Sheet products (thin sheet and thick sheet).
• Strip products.
• Wide-flange universal products.
• Bar products (round, square, strip, angle, channel, I-beam).
• Shaped products (special profiles).
• Forgings.

Steel Grades: 17Г1С, 09Г2С, 10ХСНД, 15ХСНД, 14Г2АФ, 16Г2АФ, 14ХГС, 17ГС, 10Г2С1, 10Г2БД, 12Г2СМФ, 16Г2СФ, 15ГФ, 15ХСГНДА, 15Х2Г2СФБ, 06Г2АФД and others (09Г2С and 17Г1С are the most common).

Main Requirements:

• Surface quality: the rolled product must be free of cracks, delaminations, films, overlaps, and other defects that impair its quality and reduce strength.
• Mechanical properties: must comply with the requirements established for each steel grade and rolled product thickness (yield strength, tensile strength, elongation, impact strength).
• Chemical composition: must comply with the requirements established for each steel grade.
• Weldability: steels must have good weldability (usually ensured by low carbon content and alloying elements).
• Tests: tensile tests, bending tests (for some types of rolled products), impact strength tests (to determine cold resistance), and chemical composition control are carried out.
• Marking: must be clear and contain information about the steel grade, heat number, rolled product size, standard designation, as well as additional requirements (if any).

GOST 27772-88 is a Russian standard establishing rolled steel for building steel structures. General technical conditions. It defines the requirements for chemical composition, mechanical properties, surface quality, geometric dimensions, test methods, as well as marking, packaging, transportation, and storage of sheet, wide-flange universal, bar, and shaped rolled products intended for the manufacture of building steel structures.

Main Provisions:

Application Area:

• Construction: frames of buildings and structures (industrial, civil, agricultural).
• Bridge construction: supporting structures of bridges.
• Mechanical engineering: manufacture of welded metal structures.
• Other industries: manufacture of power transmission line supports, communication towers, and other structures.

Types of Rolled Products:

• Sheet (thick sheet, thin sheet).
• Wide-flange universal (strips).
• Bar (round, square, strip, angle, channel, I-beam).
• Shaped (special profiles).

Steel Grades:

• С235, С245, С255, С285, С345, С345К, С375, С390, С390К, С440, С590. The letter “С” indicates “structural steel,” К indicates increased corrosion resistance.
• The choice of steel grade depends on the required strength characteristics, weldability, rolled product thickness, climatic conditions, and the purpose of the structure.

Main Requirements:

• Surface quality: The rolled product must be free of cracks, delaminations, films, overlaps, and other defects that impair its quality.
• Mechanical properties: Must comply with the requirements established for each steel grade (yield strength, tensile strength, elongation).
• Chemical composition: Must comply with the requirements established for each steel grade.
• Tests: Tensile tests, bending tests (for some types of rolled products), impact strength tests (for some steel grades and operating conditions) are carried out.
• Marking: Must be clear and contain information about the steel grade, heat number, rolled product size, and standard designation.

GOST 1497-84 is an interstate standard titled “Metals. Methods of Tensile Testing.” It establishes methods for static tensile testing of ferrous and non-ferrous metals and alloys to determine mechanical characteristics such as yield strength, tensile strength, percentage elongation, and percentage reduction of area.

Main Provisions:

Application Area:

• Metallurgy: quality control of products (rolled metal, forgings, castings).
• Mechanical engineering: determining the mechanical characteristics of materials used for the manufacture of machine and mechanism parts.
• Construction: determining the strength characteristics of reinforcing steel and other building materials.
• Research and development: research on the properties of new materials and alloys.

Types of Specimens:

• Round (cylindrical).
• Flat (rectangular).
• Thin sheet (for thin sheets and foil).
• Tubular (for pipes and thin-walled profiles).
• Wire (for wire and threads).
• Specimens from welded joints.

Testing Equipment: Tensile testing machine, providing the application of an axial tensile load at a specified speed.

Measuring Instruments:

• Extensometers (for accurate measurement of specimen deformation).
• Calipers and micrometers (for measuring the geometric dimensions of the specimen before and after testing).

Main Requirements:

• Specimen preparation: specimens must be manufactured in accordance with the requirements of the standard, have a smooth surface without defects, and have accurately measured dimensions.
• Specimen installation: the specimen must be installed in the grips of the tensile testing machine so that the tensile force is applied strictly along the axis of the specimen.
• Conducting the test: the test is carried out at a specified deformation rate (grip movement speed). During the test, the relationship between the applied load and the specimen deformation is recorded.

GOST 7062-90 “Forgings of Malleable Cast Iron. General Technical Conditions” - requirements for forged products made of malleable cast iron.

Main Provisions:

Application Area:

• Mechanical engineering
• Automotive industry
• Agricultural machinery construction

Main Characteristics:

• Material: malleable cast iron (requirements for chemical composition and properties).
• Types of forgings: various shapes obtained by forging.
• Dimensions: dimensional and shape tolerances (actual dimensions - according to the drawing).
• Process: forging, annealing (heat treatment for properties).

Main Requirements:

• Material quality (compliance with requirements).
• Surface quality (without defects).
• Dimensional accuracy (according to the drawing).
• Mechanical properties (according to requirements).
• Heat treatment (annealing).

Marking.

Quality control:

• Visual inspection (detection of surface defects).
• Dimensional measurement (checking compliance with drawings).
• Hardness measurement.
• Mechanical tests (determination of tensile strength and elongation).

GOST 7829-70 - “Die Forgings of Carbon and Alloy Steel. General Technical Conditions” establishes general requirements for die forgings of carbon and alloy steel.

Main Provisions:

Application Area:

• Automotive industry
• Mechanical engineering
• Transport engineering

Main Characteristics:

• Material: carbon and alloy steels.
• Type: die forgings (hot die forging).
• Dimensions: determined by the drawing, GOST establishes tolerances.
• Process: heating, forging, heat treatment, trimming, cleaning.

Main Requirements:

• Material quality (compliance with GOST standards for steels, certificate).
• Surface quality (absence of defects).
• Dimensional accuracy (compliance with the drawing).
• Mechanical properties (compliance with requirements).
• Heat treatment (according to the drawing).
• Marking.

Quality control:

• Visual inspection (detection of surface defects).
• Dimensional measurement (checking compliance with drawings).
• Hardness control.
• Mechanical tests (determination of mechanical properties).
• Ultrasonic testing (detection of internal defects - if necessary)

GOST 25054-81 “Forgings of Corrosion-Resistant, Heat-Resistant, and Heat-Strength Steels and Alloys. General Technical Conditions” defines the requirements for forgings intended for operation in aggressive environments, at high temperatures, and/or under loads.

Main Provisions:

Application Area:

• Chemical industry
• Oil and gas industry
• Energy industry
• Aviation and space industry
• Shipbuilding

Main Technical Characteristics:

• Materials: Corrosion-resistant, heat-resistant, and heat-strength steels and alloys (according to GOST standards for grades).
• Types of forgings: Various shapes obtained by forging (free forging, die forging), including shafts, disks, rings, etc.
• Dimensions: Dimensional and shape tolerances (actual dimensions - according to the drawing).
• Process: Forging (with contamination control), heat treatment (to achieve the properties of corrosion resistance, heat resistance, and heat strength).

Main Requirements:

• Material: compliance with GOST standards for steel/alloy grades, certificate. Chemical composition and the absence of defects are important.
• Surface: clean, without defects.
• Dimensions: compliance with the drawing and tolerances.
• Mechanical properties: compliance with the requirements of the drawing, taking into account operating conditions.
• Corrosion resistance: confirmation (for corrosion-resistant materials).
• Heat treatment: according to the drawing.
• Marking: mandatory.

Quality control:

• Visual inspection (detection of surface defects).
• Dimensional measurement.
• Mechanical tests (determination of mechanical properties).
• Ultrasonic testing (detection of internal defects).
• Dye penetrant or magnetic particle inspection (detection of surface defects).
• Chemical analysis (verification of the chemical composition of the steel/alloy).
• Corrosion resistance tests (if necessary).

GOST 8479-70 “Forgings of Structural Carbon and Alloy Steel. General Technical Conditions” establishes requirements for forgings obtained by forging.

Main Provisions:

Application Area:

• Mechanical engineering
• Automotive industry
• Shipbuilding
• Aviation industry
• Energy industry
• Other industries

Main Technical Characteristics:

• Material: structural carbon and alloy steels (according to GOST standards for grades).
• Types of forgings: various shapes obtained by forging (free forging, die forging), including shafts, disks, rings, etc.
• Dimensions: dimensional and shape tolerances (actual dimensions - according to the drawing).
• Process: forging (in compliance with temperature regimes), heat treatment (to achieve the required properties).

Main Requirements:

• Material: compliance with GOST standards for steels, certificate.
• Surface: clean, without unacceptable defects.
• Dimensions: compliance with the drawing and tolerances.
• Mechanical properties: compliance with the requirements of the drawing.
• Heat treatment: according to the drawing.
• Marking: mandatory.

Quality control:

• Visual inspection (detection of surface defects).
• Dimensional measurement.
• Mechanical tests (determination of mechanical properties).
• Ultrasonic testing (detection of internal defects - if necessary).
• Chemical composition control.

GOST 5762-2002 “Shut-Off Pipeline Valves. Gate Valves for Nominal Pressure not exceeding PN 250. General Technical Conditions” is a Russian standard that establishes general technical requirements for shut-off gate valves intended for use in pipeline systems with a nominal pressure not exceeding PN 250 (25 MPa). It defines requirements for the design, materials, manufacture, testing, and marking of gate valves, ensuring the shut-off of the working medium flow in pipelines of various industries.

Main Provisions:

Application Areas:

• Water supply and sewerage systems.
• Heating networks (heating, hot water supply).
• Oil and gas industry (non-aggressive media).
• Chemical industry (non-aggressive media).
• Other industrial pipelines with PN ≤ 250.

Main Technical Characteristics:

• Types of gate valves:
  • Wedge gate valves (with rising and non-rising stem).
  • Parallel slide gate valves.
• Diameter range (DN): from 15 mm to 400 mm and more, depending on the type of gate valve and pressure class.
• Pressure classes (PN): the standard covers gate valves designed to operate at various pressures not exceeding PN 250 (e.g., PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100, PN 160, PN 250).
• Materials:
  • Cast iron (gray cast iron, ductile cast iron).
  • Carbon steels (e.g., 20, 25, 35).
  • Alloy steels (e.g., 09Г2С, 15Х5М).
  • Stainless steels (e.g., 12Х18Н10Т).
• Connection types:
  • Flanged.
  • Butt-welded.
  • Threaded (socket).
  • Spigot.
• Construction: with rising or non-rising stem, with various types of sealing surfaces.
• Working media: water, steam, air, petroleum products, and other liquids and gases neutral to the gate valve materials.

Main Requirements for Gate Valves:

• Materials: compliance with GOST standards, quality certificates.
• Construction: compliance with strength, tightness, and durability requirements.
• Manufacturing quality: compliance of dimensions and shape with drawings, surface finish.
• Tightness: ensuring minimal leakage in the closed position (tightness classes).
• Strength: withstanding test pressure without failure or deformation.
• Tests: hydraulic (body strength and shut-off tightness), pneumatic (tightness).
• Marking: mandatory information about the manufacturer, DN, PN, material, flow direction arrow (if any).
• Protective coatings: paint and varnish, anti-corrosion (if necessary).

GOST 9544-2015 “Pipeline Fittings. Tightness Standards for Shut-Off Devices” - establishes permissible leakage rates through the closing member of shut-off, control, and safety valves.

Main Provisions:

Application Areas (gate valves):

• Pipelines where minimal leakage of the working medium is important (oil and gas, chemical, energy).
• Systems where leakage control is required for environmental or economic reasons.

Main Parameters:

• Types of fittings: gate valves, globe valves (valves), ball valves, butterfly valves, etc.
• Tightness classes: A (highest), B, C, D, E, F (lowest). Define the permissible level of leakage.
• Working media: not limited by the standard (tests are conducted using a medium corresponding to the working medium).

Main Requirements:

• Class compliance: fittings must comply with the declared tightness class.
• Leakage limits: leakage through the closing member must not exceed the values established for the class (tabular values in the standard depend on the diameter).
• Test methodology: strictly defined methods for measuring leakage (pressure, time, medium, measurement methods).
• Results: test report with information about the fitting and leakage values.

GOST 9697-87 “Pipeline Fittings. General Technical Conditions” - a general standard for pipeline fittings, including gate valves.

Main Provisions:

Application Areas (gate valves):

• Oil and gas
• Chemical
• Energy industries
• Housing and communal services (utilities) and others.

Main Parameters (in the context of gate valves):

• Materials: steel, cast iron, brass, bronze (body, parts).
• Pressure (Ru): nominal (rated) pressure, determining operating conditions.
• Connection types: flanged, threaded (socket), spigot, butt-welded (attachment to pipes).
• Tests: strength and tightness (hydrostatic, pneumatic).
• Marking: mandatory (manufacturer, Ru, Du, material).
• Climatic design: U, HL, T, etc. - for different conditions.

Main Requirements for Gate Valves:

• Material quality (compliance with GOST standards for steels, cast irons, alloys).
• Construction (strength, tightness, reliability).
• Manufacturing accuracy (dimensions, surface finish).
• Seals (ensuring tightness).
• Compliance with tests.
• Presence of protective coatings (anti-corrosion, if necessary).

GOST 11823-78 “Check Valves for Nominal Pressure PN < 25 MPa (250 kgf/cm2). General Technical Conditions" - establishes general technical requirements for check valves (designed to prevent backflow) operating at a pressure of less than 25 MPa (250 kgf/cm2).

Main Provisions:

Application Areas:

• Water supply and sewerage.
• Heat power engineering (heating networks).
• Oil and gas industry.
• Chemical industry.

Main Parameters:

• Types: lift, swing (clapper), ball, and other designs.
• Nominal pressure (PN): less than 25 MPa (specific PN values are determined by the technical specifications for a particular valve type).
• Materials: cast iron, carbon steel, alloy steel, stainless steel, bronze, brass (for individual parts).
• Connection types: flanged, threaded (socket), welded (butt-welded), threaded (for small diameters).

Main Requirements:

• Materials: compliance with GOST standards, availability of certificates.
• Construction: reliable prevention of backflow, strength, durability.
• Tightness: minimal leakage in the closed state under backpressure.
• Tests: for body strength and shut-off tightness.
• Marking: DN, PN, body material, manufacturer’s trademark.
• Designation: must comply with GOST 2.201

GOST 5761-2005 “Flanged Shut-Off Valves (Globe Valves), Cast Iron, Steel and Brass” - establishes general technical requirements for flanged shut-off valves (globe valves) made of cast iron, steel, and brass for a nominal pressure not exceeding 25 MPa (PN 250).

Main Provisions:

Application Areas:

• Water supply and sewerage.
• Heat power engineering (heating, hot water supply).
• Oil and gas industry (for non-aggressive media).
• Chemical industry (for compatible media).

Main Parameters:

• Types: straight-through, angle (shut-off only).
• Diameters (DN): 15-400 mm and above (depends on material and PN).
• Nominal pressure (PN): within the range up to PN 250 (6, 10, 16, 25, 40, 63, 100, 160, 250).
• Body materials: cast iron (gray, ductile), carbon steel, alloy steel, stainless steel, brass.
• Connection to the pipeline: flanged.
• Stem sealing types: gland, bellows, diaphragm.

Main Requirements:

• Materials: compliance with GOST standards, certification.
• Construction: strength, shut-off tightness, reliability.
• Manufacturing: precise dimensions, surface finish quality.
• Shut-off tightness: compliance with tightness classes (according to GOST 9544) – permissible leakage.
• Strength: withstanding test pressure.
• Tests: hydraulic tests for body strength and shut-off tightness.
• Marking: manufacturer, DN, PN, body material, flow direction arrow.

GOST 21345-78 “Taper, Ball, and Cylindrical Cocks for Nominal Pressure Ru < 25 MPa (250 kgf/cm2). General Technical Conditions" - defines general technical requirements for taper, ball, and cylindrical cocks with a nominal pressure not exceeding 25 MPa (250 kgf/cm2).

Main Provisions:

Application Areas:

• Water supply and sewerage.
• Heat power engineering.
• Oil and gas industry.
• Chemical industry.
• Other industrial pipelines.

Main Characteristics:

• Types: taper (gland and glandless), ball (full-bore and reduced-bore), cylindrical.
• Nominal pressure (Ru): less than 25 MPa (specific values are determined by the technical specifications for a particular type).
• Materials: cast iron (gray, ductile), carbon steel, alloy steel, stainless steel, bronze, brass (for parts).
• Connection types: flanged, threaded (socket), welded (butt-welded), threaded.

Main Requirements:

• Materials: compliance with GOST standards, certification.
• Construction: strength, reliability, tightness.
• Manufacturing: dimensional accuracy, quality of processing.
• Shut-off tightness: compliance with standards (determined by separate standards).
• Tests: for body strength and shut-off tightness.
• Marking: Ru, DN, body material, manufacturer’s trademark.

GOST 28908-91 “Ball Valves and Butterfly Valves. Face-to-Face Dimensions” - establishes standard face-to-face dimensions (L) for ball valves and butterfly valves with flanged and welded connections.

Main Provisions:

Application Areas:

• Water supply and sewerage systems.
• Heating networks.
• Oil and gas industry.
• Chemical industry.
• Other industries using pipeline systems.

Main Characteristics:

• Types of fittings: ball valves (shut-off and control), butterfly valves (rotary).
• Diameter range (DN): from 15 mm to 1000 mm and above.
• Nominal pressure (PN): PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100 and PN 160 (depending on DN and type of fitting).
• Connection types: flanged (various designs), butt-welded.
• Face-to-face dimension (L): the main parameter. Depends on DN, PN, and connection type. Face-to-face dimensions are given in tables in the standard.

Main Requirements:

• Face-to-face dimension compliance: manufacturers are required to manufacture fittings with face-to-face dimensions corresponding to the values specified in the standard.
• Indication in TU: the face-to-face dimension must be indicated in the technical specifications (TU) for the product.

For industrial filters, especially imported ones, standards established by manufacturers (technical specifications - TUs) are often used. There isn’t a clear national standard that covers all types of industrial filters. Standards pertaining to the materials of filtering elements (fabrics, meshes, etc.) are also applied.

GOST 14911-82 “Steel Pipeline Components. Movable Supports. Types and Main Dimensions” - establishes the classification, structural types, and main overall dimensions of movable supports intended for steel pipelines transporting various media and providing compensation for thermal elongation.

Main Provisions:

Application Areas:

• Heating networks (TPP, boiler houses).
• Petrochemical industry (refineries, chemical plants).
• Gas industry.
• Other industrial enterprises where steel pipelines are used.

Classification and Types of Movable Supports:

Sliding supports (OS):

• Sliding guide supports (OSN) - ensure the movement of the pipeline in only one direction (axial).
• Sliding non-adjustable supports (OSNn) - without the possibility of height adjustment.
• Sliding adjustable supports (OSNr) - allow adjusting the height to level the pipeline.

Roller supports (OK) - ensure the movement of the pipeline by rolling rollers.

Ball supports (OSH) - allow the movement of the pipeline in all directions.

Main Parameters and Characteristics:

• Diameter range (DN): the standard covers a wide range of nominal pipeline bores (DN) from 50 mm and above, depending on the type and design of the support. Specific values are given in the tables of the standard.
• Materials: carbon steels (St3sp, St20) and low-alloy steels (09G2S), the choice depends on climatic conditions and strength requirements.
• Main dimensions: the standard contains tables with overall dimensions for each type and design of support, including height, width, length of the base plate, diameter of rollers/balls, etc.
• Main Requirements (in addition to dimensional compliance):
• Materials: must comply with the specified steel grades and have quality certificates.
• Welding: the execution of welded joints must comply with the requirements of current standards and regulations.
• Processing quality: the surfaces of the supports must be smooth, without burrs and sharp edges.
• Protective coating: application of an anti-corrosion coating (paint and varnish materials, galvanizing) is mandatory to protect against environmental exposure.

GOST 22130-86 “Steel Pipeline Components. Movable Supports and Hangers. Technical Conditions” - establishes technical requirements and quality control methods for the production of movable supports and hangers for steel pipelines intended for ground and overground laying.

Main Provisions:

Application Areas:

• Thermal power plants (TPP).
• Oil refineries (NPZ).
• Chemical enterprises.
• Heating and hot water supply systems.
• Other industrial facilities with a developed pipeline network.

Main Parameters:

• Types of parts:
  • Movable supports: sliding (guiding), roller, ball.
  • Hangers: rigid (tie rods), spring (single- and multi-spring).
• Pipeline diameters (DN): applies to a wide range of diameters (exact values depend on the type of support/hanger and are indicated in the relevant tables).
• Materials:
  • Load-bearing elements: carbon steel (St3sp, St20), low-alloy steel (09G2S).
  • Springs: spring steel.
• Purpose: supporting the pipeline in a given position, compensating for thermal expansion, reducing vibration load, preventing deformations.

Main Requirements (apply to both supports and hangers):

• Compliance with design documentation: manufacture must strictly comply with approved drawings.
• Materials: all materials must comply with the specified grades and have quality certificates. Incoming inspection is mandatory.
• Welding: welds are performed according to established technologies and are subject to control (visual, ultrasonic, or radiographic).
• Heat treatment: may be required to relieve internal stresses after welding.
• Machining: dimensional accuracy and surface quality must meet the requirements of the drawings.
• Anti-corrosion protection: application of protective coatings is mandatory (primer, enamel, galvanizing, etc.).
• Acceptance tests: visual inspection, dimensional check, strength tests (for individual elements), inspection of weld quality (if applicable).
• Marking: clear and durable marking containing information about the type of product, DN, date of manufacture, batch number, quality control stamp.
• Packaging and transportation: products must be packaged and protected from damage during transportation and storage.

OST 36-146-88 “Supports for Steel Process Pipelines for Ru up to 10 MPa. Design” - establishes the types, designs, and main dimensions of steel supports for above-ground and overground installation of process pipelines with a nominal pressure up to 10 MPa.

Main Provisions:

Application Areas:

• Chemical and petrochemical industry.
• Oil refining industry.
• Energy (heating networks).
• Other industries where process pipelines are used for transporting liquids and gases.

Main Parameters:

Types of supports:

• Movable: sliding (guiding), roller, ball.
• Fixed: welded (plates, angles, studs), clamp (for attachment to building structures), front.
• Pipeline diameters (DN): OST applies to pipelines with various nominal bores (DN), depending on the type of support. Dimensions are given in the tables of the standard.
• Nominal pressure (Ru): up to 10 MPa (100 kgf/cm2).
• Materials: carbon steels (St3sp, St20), low-alloy steels (09G2S). The use of other materials, agreed upon in the established manner, is permitted.
• Construction: detailed drawings with all dimensions and tolerances for each type of support (base plates, stiffeners, clamps, fastening elements).

Main Requirements:

• Compliance with drawings: the manufacture of supports must strictly comply with the drawings provided in OST 36-146-88. Any deviations must be agreed with the design organization.
• Materials: the materials used must meet the requirements of the steel grades specified in OST and have quality certificates.
• Welding: welds must be performed in accordance with current norms and rules, with mandatory quality control of welds.
• Anti-corrosion protection: supports must be protected from corrosion by paint and varnish or other coatings resistant to the effects of the environment and the transported medium.
• Marking: each support must have clear and durable marking containing information about the type of support, pipeline diameter, and drawing number.

GOST 24140-80 “Pipeline Fastening Parts. Stirrups and Clamps. Technical Conditions” - establishes technical requirements, acceptance rules, control methods, and tests for stirrups and clamps intended for the fixed fastening of pipelines to building structures and equipment.

Main Provisions:

Application Areas:

• Pipelines for various purposes (water supply, heating, gas supply, oil pipelines, process pipelines).
• Industrial and civil construction.

Types of Parts:

• Stirrups: U-shaped, U-shaped, stirrups with tabs, stirrups for fastening to channels, angles, etc.
• Clamps: clamps with bolt tabs, clamps with rubber inserts, clamps with welded nuts (the design of the clamps is defined by GOST 24137-80).

Materials:

• Carbon steels (St3sp, St20, 08kp) - for general use.
• Low-alloy steels (09G2S) - for use in low-temperature conditions.
• Stainless steels (12Х18Н10Т, 08Х18Н10) - for use in aggressive environments.

Protective Coatings:

• Galvanizing (electroplating or hot-dip).
• Painting (primer, enamel).
• Oxidation (for carbon steels).
• Polymer coatings.

Main Requirements established by the standard:

• Material quality: compliance with the steel grades specified in the standard, availability of quality certificates.
• Manufacturing accuracy: compliance with the drawings and dimensions specified in the design documentation.
• Quality of welded joints (if any): compliance with the requirements of current welding standards.
• Quality of protective coatings: absence of defects, sufficient thickness, good adhesion.
• Mechanical properties: tensile strength, hardness (depending on the material).

GOST 24137-80 “Pipeline Fastening Parts. Clamps. Design and Dimensions” - describes the design, main dimensions, and materials of clamps intended for fastening pipelines for various purposes to building structures or technological equipment.

Main Provisions:

Application Areas:

• Water supply and heating systems (housing and communal services).
• Oil and gas industry.
• Chemical industry.
• Construction.

Other industries where pipelines are used.

Types of Clamps (main designs):

• Clamps with bolt tabs: for fastening to flat surfaces using bolted connections.
• Clamps with rubber inserts (gaskets): for reducing vibration and noise, as well as preventing damage to the pipe surface.
• Clamps with welded elements: for fastening to metal structures by welding.

Main Parameters:

• Pipeline diameters (DN): applies to a wide range of diameters, depending on the type of clamp. Specific dimensions and correspondence to pipe diameters are given in tables.
• Materials:
  • Carbon steels (St3, St20, etc.) for general use.
  • Corrosion-resistant steels (stainless steels) for aggressive environments.
• Structural elements: the standard establishes the dimensions of the following elements:
  • Width of the clamp strip.
  • Metal thickness.
  • Dimensions of the fastening tabs.
  • Diameters of the mounting holes.
  • Bending radius.

Main Requirements:

• Compliance with drawings: manufacture must exactly comply with the drawings given in the standard.
• Materials: all materials must comply with the specified grades and have quality certificates.
• Surface quality: absence of burrs, sharp edges, cracks, and other defects.
• Corrosion protection: mandatory application of protective coatings (galvanizing, painting, polymer coatings) to protect against environmental exposure.
• Fastening strength: clamps must provide reliable fastening of the pipeline and withstand the loads that occur during operation.

The standard covers austenitic stainless steel pipes manufactured by a welding process with or without subsequent seam treatment. Pipes according to this standard are intended for operation under high pressure and corrosion.

Key technical specifications:

1. Materials:
   • Made of austenitic stainless steel (e.g., grades 304, 304L, 316, 316L and others).
   • Chemical composition is controlled to ensure high corrosion resistance and strength.
2. Application:
   • Used in the chemical, petrochemical, energy industries, and in the construction of pipelines for the transportation of aggressive media.
   • Suitable for operation in low and high-temperature conditions.
3. Size Range:
   • Outer diameter: from 8 inches (200 mm) and larger.
   • Wall thickness: regulated according to calculated pressure requirements and customer specifications.
4. Mechanical Properties:
   • High tensile and yield strength.
   • Elongation: not less than 30%.
5. Testing and Quality Control:
   • Hydrostatic testing to verify tightness.
   • Inspection of weld seams using non-destructive methods (radiographic or ultrasonic).
   • Verification of chemical composition and mechanical properties in accordance with the specification.
6. Corrosion Resistance:
   • High resistance to intergranular corrosion and the effects of chemically active substances.

The European standard covering welded pipes made of corrosion-resistant stainless steel intended for pressurized applications. Pipes according to this standard are used in the chemical, oil and gas, food and pharmaceutical industries, as well as in drinking water supply systems. Key technical specifications:

1. Materials:
   • Pipes are made of corrosion-resistant stainless steel grades, such as AISI 304, 304L, 316, 316L and other similar composition grades.
   • Steels according to this standard have high corrosion resistance and excellent mechanical strength.
2. Application:
   • Pipelines for transporting liquids and gases under pressure.
   • Used in the food, chemical, pharmaceutical, energy, and other industries where high corrosion resistance is required.
   • Suitable for operation at low and high temperatures.
3. Dimensions and Wall Thickness:
   • The outer diameter of the pipes varies from 6 mm to 2500 mm.
   • The wall thickness is selected depending on the pressure and operating conditions.
4. Mechanical Properties:
   • The yield and tensile strength depend on the steel grade and the type of heat treatment.
   • Elongation at break varies from 20% to 40%, depending on the steel grade.
5. Testing Requirements:
   • Hydrostatic testing: verifying the tightness of the pipe under pressure.
   • Tensile testing: determining the strength and yield strength of the steel.
   • Impact toughness test: performed at low temperatures to check the material’s resistance to brittle fracture.
   • Non-destructive testing of the weld seam: radiographic or ultrasonic testing to detect internal defects.
6. Quality Control:
   • Checking the geometry of the pipe (diameter, wall thickness, ovality).
   • Checking the chemical composition for compliance with regulatory requirements.
   • Visual inspection of welds and the pipe surface for defects (cracks, dents, corrosion).

The technical specifications regulate the requirements for seamless cold-worked and hot-worked pipes made of stainless and corrosion-resistant steel. These pipes are used in various industries, including oil and gas, chemical, energy, and food, where there are increased requirements for metal resistance to corrosion, temperature loads, and mechanical stresses.

1. Main Steel Grades

   Various grades of stainless and corrosion-resistant steels are used for the production of pipes according to TU 14-3R-197-2001, among which:

   • 08Kh18N10T – AISI 321 analogue, used for operation at high temperatures and aggressive environments.
   • 12Kh18N10T – AISI 304/304L analogue, used for transporting aggressive media.
   • 10Kh17N13M2T – improved alloy with increased resistance to corrosion and aggressive media.
   • Other heat-resistant and corrosion-resistant steel grades suitable for specific operating conditions.
2. Dimensions and Tolerances
   • Outer diameter of pipes – from 6 mm to 426 mm (depends on the production method).
   • Wall thickness – from 0.5 mm to 40 mm (for hot-worked pipes – thicker walls).
   • Pipe length – measured and unmeasured length from 1 m to 12 m (as agreed with the customer).
   • Dimensional tolerances – deviations in diameter and wall thickness are minimal for cold-worked pipes and more significant for hot-worked pipes.
3. Mechanical Properties
   • Strength and ductility – pipes according to TU 14-3R-197-2001 have high mechanical properties that depend on the steel grade and processing technology.
   • Hardness – the hardness level meets the requirements for stainless steels (usually no higher than 200 HB).
   • Operating temperature range – from -70°C to +600°C (depending on the steel grade).
   • Corrosion resistance – due to the use of stainless steel grades, the pipes are resistant to corrosion in aqueous media, acids, and alkalis.
4. Quality Control and Testing

   The production process of pipes according to TU 14-3R-197-2001 includes strict quality control, which is carried out in the following areas:

   • Tensile test – tensile and yield strength are checked.
   • Hydraulic test – pipes are tested with water or air pressure to detect leaks.
   • Bending test – the resistance of pipes to bending without cracks and deformations is checked.
   • Non-destructive testing – magnetic and ultrasonic flaw detection is performed to identify internal defects.
   • Geometric dimension control – the outer diameter, wall thickness, and length of the pipe are measured.
5. Advantages of pipes according to TU 14-3R-197-2001
• Strength and durability – the pipes withstand high loads and temperature fluctuations.
• Resistance to aggressive environments – stainless steels are protected from corrosion, which increases the service life of products.
• Tightness – the pipes undergo hydraulic leakage tests.
• High dimensional accuracy – ensured by the use of cold-worked technology.
• Universality of application - pipes are applicable in the chemical, food, oil and gas, energy and other industries.

The State Standard regulating requirements for cold-worked seamless corrosion-resistant (stainless) steel tubes, intended for operation in aggressive environments, high temperatures, and pressure. This standard is used in the petrochemical, chemical, energy, and food industries.

1. Types of Tubes and Manufacturing Methods
   • Type of tubes - cold-worked seamless tubes (as opposed to hot-worked tubes according to GOST 9940-81).
   • Manufacturing process - the tubes are produced by cold deformation, followed by heat treatment, which ensures their precise dimensions and high operational characteristics.
   • Material - corrosion-resistant stainless steel grades:
     • 08Kh18N10T
     • 12Kh18N10T
     • 10Kh17N13M2T
     • Other alloys with the addition of nickel, chromium, and molybdenum to increase resistance to corrosion and temperature effects.
2. Dimensions and Tolerances
   • Outer diameter of tubes - from 2 mm to 426 mm.
   • Wall thickness - from 0.2 mm to 50 mm (depending on the type of tube and purpose).
   • Length of tubes - multiple sizes or measured length from 2 m to 30 m.
   • Tolerances on diameter and wall thickness - for cold-worked tubes, minimum tolerances are provided, which makes them accurate and suitable for precision applications.
3. Mechanical Properties
   • Strength and ductility - the tubes provide high strength under load and retain ductility.
   • Hardness - for various steel grades, the hardness limit is controlled, for example, for 12Kh18N10T - no more than 200 HB.
   • Temperature resistance - the tubes retain their strength characteristics at high temperatures (from -70°C to +600°C).
4. Quality Control and Testing

   The production process of tubes according to GOST 9941-81 is accompanied by strict quality control:

   • Tensile test - checks yield strength and tensile strength.
   • Hydrostatic test - tubes are tested under water or air pressure to check for leaks.
   • Bending test - the ductility of the tube and resistance to bending without the formation of cracks and deformations are checked.
   • Non-destructive testing - ultrasonic or magnetic flaw detection is performed to detect hidden defects.

Control of geometric parameters - measurements of outer diameter, wall thickness, and curvature of the tube.

The State Standard establishes requirements for seamless pipes made of corrosion-resistant (stainless) steel, used for various technical purposes, including operation under high pressure, at high temperatures, and in aggressive environments.

1.Key provisions and characteristics

Purpose and Scope Pipes according to GOST 9940-81 are used in the following industries:

• Oil and gas industry (transportation of aggressive substances);
• Chemical and petrochemical industry (aggressive environments and high temperatures);
• Power engineering (pipelines for steam and hot water);
• Food and pharmaceutical industry (where hygienic safety and corrosion resistance are required).

2. Material

• Pipes are made of stainless steel of various grades, for example, 08Kh18N10T, 12Kh18N10T, 10Kh17N13M2T, and others.

3. Dimensions and Permissible Deviations

• Pipe diameter – from 5 mm to 426 mm
• Wall thickness – from 0.5 mm to 50 mm (depends on the production method and application).
• Pipe length – multiple sizes or measured length from 2.0 m to 30 m.
• Ovality and curvature – regulated by tolerances for ovality and deviations from straightness.

4. Mechanical Properties

Mechanical properties depend on the steel grade and heat treatment method. Approximate parameters:

• Tensile strength (σв) – from 490 to 590 MPa (depending on the steel grade).
• Elongation (δ) – from 35% to 40%.
• Hardness – no more than 200 HB (for austenitic stainless steels).

5. Heat Treatment

• To improve mechanical properties and eliminate internal stresses, the pipes are subjected to quenching and tempering.
• Heat treatment of welds is possible to improve the metal structure.

6. Quality Control and Testing

The production process of pipes according to GOST 9940-81 is accompanied by strict quality control:

• Tensile test – checks yield strength and tensile strength.
• Bending test – the pipe must withstand bending without failure.
• Hydrostatic test – checks for tightness under pressure.
• Impact toughness test – especially important at low temperatures.
• Geometry control – measurement of outer diameter, wall thickness, and pipe curvature.

Non-destructive testing – ultrasonic testing to detect hidden defects.

The standard applies to seamless and welded stainless duplex steel pipes intended for service in highly corrosive and high-pressure conditions. Key technical specifications:

1. Materials:
   • Manufactured from duplex stainless steel (austenitic-ferritic), including grades UNS S31803 (2205), S32750 (2507), S32760, and others.
   • Materials provide high corrosion resistance, including resistance to pitting corrosion, stress corrosion cracking, and erosion corrosion.
2. Application:
   • Used in marine environments, the oil and gas industry, the chemical industry, and in the production of water desalination equipment.
   • Suitable for transporting corrosive liquids, chemicals, and gases.
3. Size Range:
   • Outside diameter of pipes: from 1/8 inch (3.2 mm) and larger.
   • Wall thickness varies according to pipeline schedules (Schedule 10, 40, 80, and others).
4. Mechanical Properties:
   • Tensile Strength: not less than 620 MPa (90,000 psi) for most steel grades.
   • Yield Strength: not less than 450 MPa (65,000 psi).
   • Elongation at Break: 25% and higher.
5. Corrosion Resistance:
   • High resistance to corrosion in chloride-containing environments.
   • Excellent resistance to intergranular corrosion.
6. Testing and Inspection:
   • Hydrostatic testing.
   • Testing for corrosion resistance and verification of mechanical properties.
   • Weld seam inspection (for welded pipes), including non-destructive testing methods.

ASTM A312 standard covers seamless, welded, and heavily cold worked austenitic stainless steel pipes intended for high temperature and general corrosive service.

Materials:

• Pipes are manufactured from austenitic stainless steel grades 304, 316, 321, 347, and others.
• Materials provide high corrosion resistance and mechanical strength.

Application:

• Intended for operation in aggressive environments, high temperatures, and pressures.
• Used in the oil and gas, chemical, and energy industries.

Size Range:

• Outside diameter of pipes: from 1/8 inch (3.2 mm) to 30 inches (762 mm).
• Wall thickness: varies depending on standard schedules (Schedule 5S, 10S, 40S, and others).

Mechanical Properties:

• Minimum Tensile Strength: 515 MPa (75,000 psi).
• Minimum Yield Strength: 205 MPa (30,000 psi).
• Elongation at Break: Not less than 35% for most steel grades.

Testing and Inspection:

• Hydrostatic test to check for leaks.
• Non-destructive quality control of the weld seam (for welded pipes).
• Verification of dimensions, chemical composition, and mechanical properties.

ASTM A269 standard specifies the requirements for seamless and welded austenitic stainless steel tubing for general service, including applications involving corrosive media and high temperatures.

Materials: Tubes are manufactured from austenitic stainless steel grades, such as 304, 316, 316L, and others, providing corrosion resistance.

Size Range:

• Outside diameter of tubes: from 1/8 inch (3.2 mm) to 5 inches (127 mm).
• Wall thickness: from 0.020 inch (0.51 mm) and greater.

Dimensional Tolerances: Deviations in outside diameter, wall thickness, and tube length are strictly regulated according to customer requirements.

Mechanical Properties:

• Minimum Tensile Strength: 515 MPa (75,000 psi).
• Minimum Yield Strength: 205 MPa (30,000 psi).
• Elongation at Break: Not less than 30%.

Tests and Inspections:

• Mandatory hydrostatic testing.
• Non-destructive testing, including checks for weld integrity (for welded tubes).

ASTM A213 standard specifies the requirements for seamless ferritic and austenitic alloy stainless steel tubes of grades TP 304, TP 316, TP 304L, TP 316L, TP 321, intended for use in boilers, heat exchangers, and other high-temperature applications.

Chemical Composition: the tubes are manufactured from austenitic stainless steel grades such as 304, 316, 321, etc., with a chromium (Cr) content ranging from 18% to 20% and a nickel (Ni) content ranging from 8% to 14%, depending on the alloy.

Mechanical Properties:

• Tensile Strength: Minimum 515 MPa (75,000 psi).
• Yield Strength: Minimum 205 MPa (30,000 psi).
• Elongation at Break: Not less than 35% (for standard tube diameters).

Dimensional Tolerances:

• Tube diameters range from 1/8 inch (3.2 mm) to 30 inches (762 mm).
• Wall thickness – from a minimum thickness of 1.24 mm to required values as per order.

Tests and Inspections: each tube must undergo a hydrostatic test, as well as checks for radiographic soundness of welds (for welded tubes) and corrosion resistance.

The standard establishes the technical conditions for seamless and welded steel pipelines for the oil, gas, and other industries, intended for operation under pressure and temperature.

Key Technical Characteristics:

Purpose:

• The standard applies to pipes that are used to transport oil, gas, and chemical substances, as well as in pipeline systems of various industrial sectors.
• Pipes can be used in both underground and above-ground pipelines, as well as in equipment subject to high temperature and mechanical loads.

Pipe Types:

• The standard covers both seamless and welded pipes.
• Carbon and low-alloy steels are used, which provide the required strength and corrosion resistance in various operating conditions.

Pipe Sizes:

• The pipe diameter varies from 32 mm to 530 mm.
• The wall thickness of the pipes can be from 3 mm to 40 mm.

Mechanical Characteristics:

• Pipes are subject to requirements for tensile strength and elongation.
• The tensile strength must be at least 370 MPa, and the elongation must be at least 20%.
• Testing for corrosion resistance.

Testing:

• Pipes undergo hydraulic tests for leak tightness at high pressure.
• Tests for strength and hardness are carried out to confirm mechanical properties.
• Non-destructive testing methods are mandatory to detect possible defects (e.g., ultrasonic flaw detection).

The standard specifies technical conditions for seamless and welded steel pipes intended for use in the oil, gas, chemical, and other industries.

Key Characteristics:

Pipe Types:

• Seamless and welded pipes made of carbon and low-alloy steels, which are intended for use in various industrial sectors, including the petrochemical, gas, and chemical industries.

Materials:

• Carbon steels (e.g., 20, 45, 10G2F) and low-alloy steels (e.g., 15KhM, 12Kh1MF).
• Pipelines for operation in moderate temperature and pressure conditions.

Diameters and Wall Thickness:

• Pipelines can be of various diameters: from 25 to 530 mm.
• Pipe wall thickness: from 2 to 30 mm, depending on the purpose and steel grade.

Application:

• Used for pipeline systems in the petrochemical, gas, chemical, and other industries, including equipment that operates at normal and elevated temperatures.
• Also used for the manufacture of pipes for water and gas supply systems.

Testing and Quality Control:

• Mechanical tests for strength, elongation, and hardness.
• Hydraulic tests to check the tightness of pipes under pressure.
• Non-destructive testing - ultrasonic inspection for defects.
• Inspection for external defects: chips, cracks, bent areas, etc.

The standard specifies the technical conditions for the manufacture and control of seamless steel pipes manufactured by hot and cold deformation methods. GOST 8731-74 is used in conjunction with GOST 8732-78 (for hot-deformed pipes) and GOST 8734-75 (for cold-deformed pipes). This standard is used in the oil and gas, petrochemical, energy, and mechanical engineering industries.

Key Characteristics:

Pipe Type:

• Seamless hot-deformed and cold-deformed pipes.

Application:

• Production of pipes for pipeline systems operating under pressure.
• Use in petrochemistry, oil refining, heat power engineering, and mechanical engineering.
• Heat transfer systems (steam pipes and heating networks) and gas pipelines.

Materials:

• Carbon steels (e.g., grades St10, St20).
• Alloy steels (e.g., 09G2S, 15KhM, 12Kh1MF) - for operation in conditions of elevated temperatures and corrosive media.

Pipe Diameters and Sizes:

• Outer diameter of pipes: from 20 to 550 mm (for hot-deformed).
• Wall thickness: from 2.5 to 75 mm.
• For cold-deformed pipes, the diameter and wall thickness may vary within smaller ranges.

Quality Control and Testing:

• Mechanical tests: checking the strength, elongation, and impact toughness.
• Hydraulic tests: checking the tightness of pipes under water pressure.
• Ultrasonic testing: inspection for internal defects and cracks.
• Visual inspection: checking the surface for defects (laps, cracks, shells).

Features:

• Pipes can be manufactured with normal and increased accuracy in wall thickness and diameter.
• Can have definite and random length (usually from 4 to 12 meters).

The standard specifies the technical conditions for seamless pipes made of carbon and alloy steels intended for operation in conditions requiring resistance to high temperatures and pressures. This standard applies to pipes used in heat power engineering, the petrochemical and oil industry, as well as in mechanical engineering.

Key Characteristics:

Pipe Types:

• Seamless pipes manufactured by hot and cold deformation methods.
• Used in pipelines operating at high pressures and temperatures.

Materials:

• Carbon and alloy steels (e.g., 15KhS, 15KhM, 12Kh1MF, 09G2S, and others).
• Pipelines for operation in aggressive environments.

Diameter and Wall Thickness:

• Pipe diameter: from 25 to 530 mm (for hot-deformed pipes).
• Wall thickness: from 2 to 50 mm (depending on the pipe diameter).

Application:

• Pipelines for transporting oil, gas, and chemical substances.
• Steam pipes and heat pipelines operating in high-temperature conditions.
• Elements of heat exchangers, boilers, and other units in the power industry.

Use in mechanical engineering and shipbuilding for the manufacture of various parts of mechanisms.

Testing and Quality Control:

• Mechanical tests for strength, elongation, and impact toughness.
• Hydraulic tests to check the tightness of pipes under pressure.
• Ultrasonic inspection for internal defects.
• Visual inspection of the surface to identify external defects.

The standard regulates the production of seamless hot-deformed steel pipes. These pipes are used in the petrochemical, oil and gas, energy, construction, and other industries where strong and reliable piping systems operating under high pressure and high temperatures are required.

Key characteristics:

Pipe Type:

Seamless, hot-deformed steel pipes.

Application:

Pipelines for transporting oil, gas, and chemical products.

Heating networks and heat exchange systems.

Production of pipeline fittings, flanges, and other connecting elements.

Pipe Diameters:

Outer diameter: 25 mm – 550 mm.

Wall Thickness:

2.5 mm – 75 mm, depending on the pipe diameter and operating requirements.

Pipe Length:

Definite length: from 4 to 12 meters (as ordered).

Random length: from 4 to 12.5 meters.

Material:

Carbon and alloy steel (steel grades St10, St20, 09G2S, 12Kh1MF, and others).

Materials are selected depending on the operating conditions (corrosive environment, temperature, pressure).

Classification by Manufacturing Accuracy:

Normal accuracy.

Increased accuracy (for individual customer requirements).

Testing and Control:

Visual inspection of the surface (free from cracks, laps, shells).

Ultrasonic and hydraulic testing for tightness and strength.

Control of mechanical properties (testing for tensile strength, impact toughness, elongation).

This international standard specifies the requirements for carbon or low-alloy steel pipes for pipelines used to transport oil, gas, and water in high-pressure systems.

Key Characteristics:

1. Material: Carbon and low-alloy steel.
2. Pipe Types:
• Seamless — for increased strength and resistance requirements.
• Electric Resistance Welded (ERW, HFW, LSAW) — used for longer pipelines.
3. Strength Levels (Specification Levels):
• PSL 1 — standard quality for normal operating conditions.
• PSL 2 — increased requirements for strength, impact toughness, and chemical composition.
4. Pipe Grades: From Grade A to Grade X80 (the number X indicates the minimum yield strength value, for example, X42 — 42,000 psi ≈ 290 MPa).
5. Application:
• Transportation of oil, gas, and water over long distances.
• Used in the oil and gas, energy, and water supply industries.

API 5L is used for the production of main pipelines, providing high reliability and resistance to mechanical loads, corrosion, and pressure.

ASTM A106 (Grade A, B, C) - intended for seamless carbon steel pipes used in high-temperature and high-pressure applications.

Key technical specifications for Grades A and B:

Chemical Composition (in %):

• Grade A:
• Carbon (C): up to 0.25%
• Manganese (Mn): 0.27-0.93%
• Phosphorus (P): no more than 0.035%
• Sulfur (S): no more than 0.035%
• Silicon (Si): at least 0.10%
• Grade B:
• Carbon (C): up to 0.30%
• Manganese (Mn): 0.29-1.06%
• Phosphorus (P): no more than 0.035%
• Sulfur (S): no more than 0.035%
• Silicon (Si): at least 0.10%

• Yield Strength (Re):
• Grade A: not less than 205 MPa
• Grade B: not less than 240 MPa
• Tensile Strength (Rm):
• Grade A: 330-485 MPa
• Grade B: 415-585 MPa
• Elongation (A):
• Depends on the wall thickness and pipe diameter, typically around 20-30%.

• Pipe Diameters: from NPS 1/8” to NPS 48”.
• Wall Thickness: in accordance with Schedules 20, 40, 80 and higher.

• Hydrostatic pressure tests, non-destructive testing (e.g., ultrasonic and eddy current testing) are performed.
• Tensile, flattening, and bending tests.

• Used in high-pressure and high-temperature systems, such as oil and gas pipelines, heat exchangers, boiler installations, and other process lines in the petrochemical and energy industries.

Main difference between A and B:

Grade A has lower mechanical characteristics compared to Grade B and is used in less demanding conditions. Grade B is more in demand for pipelines with high requirements for mechanical strength.

This European standard specifies requirements for seamless pipes made of carbon and alloy steel for use in pipelines operating at high pressures and temperatures. The standard includes two parts:

• EN 10216-1 — general technical delivery conditions for pipes, including mechanical properties and testing.
• EN 10216-2 — specific requirements for pipes made of alloy steels intended for use at high temperatures.

Key characteristics of the second section of the EN 10216-2 standard include:

1. Materials:

   Pipes are made of alloy steels that have improved mechanical properties and can withstand high temperatures. The materials used include steels with additives such as Cr (chromium), Mo (molybdenum), and other alloying elements that increase heat resistance and corrosion resistance.

2. Mechanical Properties:
   • Minimum tensile strength for pipes up to 50 mm in diameter:

   • 500 MPa — for steel 13CrMo4-5.

   • 510 MPa — for steel X10CrMoVNb9-1.

   • Minimum yield strength:

   • 225 MPa — for steel 13CrMo4-5.

   • 250 MPa — for steel X10CrMoVNb9-1.

   • Minimum elongation at 50 mm (in percent):

   • 22% for 13CrMo4-5.

   • 20% for X10CrMoVNb9-1.

   • Minimum impact toughness:

   • 27 J at a temperature of -20°C for steel 13CrMo4-5.

   • 40 J at -20°C for steel X10CrMoVNb9-1.

3. Dimensions and Tolerances:
   • Pipe diameters: from 10 mm to 273 mm.
   • Wall thickness: from 1.0 mm to 30 mm (depending on the pipe diameter).
   • Diameter tolerances: ± 0.5 mm for pipes with a diameter of up to 100 mm, ± 1.0 mm for pipes with a diameter of more than 100 mm.
   • Wall thickness tolerances: ± 10% of the nominal thickness
4. Testing:
   • Hydrostatic testing: pipelines are subject to leakage testing with a hydrostatic pressure equal to at least 1.5 times the nominal working pressure.

Tensile testing: pipe specimens undergo tensile testing according to EN 10216-2, complying with the minimum strength values.

This international standard specifies requirements for seamless and welded pipes made of low-temperature carbon and alloy steel. These pipes are intended for service at low temperatures and retain their strength characteristics even at extremely low temperatures, such as -45°C and below. Their main applications include cryogenic plants, the oil and gas industry, and the chemical and energy industries.

1. Steel Grades

   ASTM A333 includes several steel grades that differ in chemical composition and mechanical properties:

   • Grade 1 — carbon steel, widely used for low-temperature conditions.
   • Grade 6 — alloy steel with improved impact toughness characteristics.
   • Grades 3, 4, 7, 8, 9, 10, 11 — special steel grades for operation in even more extreme conditions.

The steel grades include alloying elements such as manganese (Mn), silicon (Si), phosphorus (P), sulfur (S), and small amounts of other additives.

2. Main Pipe Dimensions
   • Outer diameter of pipes — from 10.3 mm to 1219 mm (from 1/8 inch to 48 inches).
   • Wall thickness — from 1.65 mm to 40 mm (0.065 inches and above).
   • Pipe length — pipes are supplied in random length, definite length, and cut length as per customer request.
3. Mechanical Properties

   Pipes according to ASTM A333 have the following properties:

   • Yield Strength — the minimum value depends on the grade and is about 240–415 MPa.
   • Tensile Strength — not less than 415 MPa.
   • Elongation — determined according to the standard and depends on the wall thickness.
   • Impact Toughness — pipes undergo impact testing at low temperatures to check their resistance to brittle fracture.
4. Testing and Quality Control

   The pipe control process according to ASTM A333 includes:

   • Impact testing — checking the toughness of the metal at low temperatures (e.g., at -45°C).
   • Tensile testing — checking the strength and elongation of the material.
   • Hydraulic testing — pipes are checked under pressure to ensure their tightness.
   • Non-destructive testing — ultrasonic and magnetic flaw detection are performed to detect cracks and defects.

Dimensional and geometric control — measuring the outer diameter, wall thickness, and length of the pipe.

GOST 17379-2001 is a Russian standard that regulates the technical requirements for flanges for piping systems operating at high pressures. The standard describes flanges used to connect pipelines operating in high temperature and pressure conditions and is used in various industries, such as oil and gas, chemical, energy, and others.

Main Provisions of GOST 17379-2001:

• Scope:
  • The standard applies to flanges used in pipelines operating under a pressure of 1.6 MPa to 25 MPa and higher.
  • It covers flanges for piping systems that can be operated at high pressures and temperatures, including systems operating with aggressive chemicals.
• Flange Types:
  • GOST 17379-2001 flanges can be flat, welded, and weld-on, as well as with various types of connections.
  • Depending on the operating conditions, the flanges may have different wall thicknesses, the diameter of which varies from 15 mm (DN 15) to 1500 mm (DN 1500) and more.
• Materials:
  • Flanges manufactured according to GOST 17379-2001 can be made of carbon, alloy, and stainless steels.
  • Depending on the operating conditions, the flanges can be made of materials more resistant to corrosion and high pressure, such as 12Kh18N10T, 15Kh5M, 20, 09G2S, and others.
• Pressure Classes:
  • The standard establishes several pressure classes for which the flanges are intended, including 16 MPa, 25 MPa, 40 MPa, and others, depending on the requirements for the piping system.
  • Flanges manufactured according to GOST 17379-2001 can be used for pipelines operating in extreme conditions, such as in oil and gas wells, heat exchangers, and other highly loaded systems.
• Testing:
  • All flanges manufactured according to GOST 17379-2001 must undergo a hydrostatic pressure test with a pressure that exceeds the working pressure by 1.5 times to check their tightness and strength.
  • Additional tests may also be carried out for resistance to high pressure, temperature fluctuations, and exposure to aggressive chemicals.
• Application:
  • GOST 17379-2001 is used for piping systems in the oil and gas industry, chemical industry, energy sector, as well as in other industries where the use of piping systems operating under high pressure and temperature is required.
  • This standard is applicable for pipelines that transport oil, gas, chemicals, as well as for systems used in heat exchangers and other highly loaded installations.

GOST 17376-2001 is a Russian standard that regulates the production of flanges and pipeline connections for systems operating under pressure. The standard is more focused on flanges with large diameters and for higher pressures. It includes stricter requirements for flanges for special operating conditions.

It establishes requirements for flanges used in piping systems, including their dimensions, materials, testing methods, and quality. This standard applies in various industries, including oil and gas, chemical, and energy.

Key Technical Specifications

• Flange Types:
  • Welded flanges (for connections with pipes by welding).
  • Flanges with large diameters, which are used in larger and more heavily loaded pipelines.
• Diameter Range:
  • GOST 17376-2001 flanges can be manufactured for pipelines with diameters from 50 mm (DN 50) to 2500 mm (DN 2500) and larger.
• Pressure Classes:
  • GOST 17376-2001 flanges are designed to operate at higher pressures, for example, 6.3 MPa, 10 MPa, 16 MPa, 25 MPa, and higher.
• Materials:
  • Carbon steels (e.g., 20, 09G2S, 09G2).
  • Stainless steels (e.g., 12Kh18N10T).
  • Alloy steels (e.g., 15Kh5M, 16GS).
• Wall Thickness and Dimensions:
  • The standard establishes precise dimensions for flanges, including wall thickness, hole diameter, and other parameters, to ensure the strength of connections and their tightness.

• Material Quality:
  • All materials for the manufacture of flanges must comply with established quality standards and have appropriate certificates confirming their compliance with mechanical and chemical requirements.
• Welding and Connections:
  • For welded flanges, strict requirements must be observed for the quality of welds to avoid defects such as cracks, pores, and other damages.
• Testing:
  • Flanges must undergo a hydrostatic pressure test, which exceeds the operating pressure, to check the tightness and strength of the connections.
• Surface Treatment:
  • Flange surfaces must be cleaned of contaminants, rust, and other defects, and treated to prevent corrosion and improve sealing properties.

GOST 17375-2001 is a Russian standard that regulates the production of flanges for piping systems operating under pressure. It defines technical requirements, testing methods, as well as requirements for the quality and materials of flanges used in pipelines in various industries, including oil and gas, chemical, energy, and others.

Purpose

GOST 17375-2001 standard is intended for flanges used to connect piping systems operating under pressure. It provides standardization of dimensions, materials, mechanical properties, and testing methods, which allows ensuring the reliability and safety of pipeline connections.

Key Technical Specifications

• Flange Types:
  • Flat flanges (for connections with bolts and nuts).
  • Welded flanges (for connections with pipes by welding).
  • Weld-on flanges.
• Diameter Range:
  • From 15 mm (DN 15) to 1500 mm (DN 1500) and more, depending on the pressure class and flange type.
• Pressure Classes:
  • The standard covers flanges intended for operation at medium pressures, for example, 0.25 MPa, 0.6 MPa, 1.0 MPa, 1.6 MPa, 2.5 MPa, 4.0 MPa.
• Materials:
  • Carbon steels (e.g., 20, 09G2S).
  • Stainless steels (e.g., 12Kh18N10T).
  • Alloy steels (e.g., 15Kh5M).
• Wall Thickness and Dimensions:
  • The wall thickness of flanges and other geometric parameters are strictly regulated by the standard to ensure the strength and tightness of connections.

Key Requirements

• Material Quality:
  • Materials for the manufacture of flanges must comply with the steel grades specified in the standard and have quality certificates confirming their compliance with mechanical and chemical requirements.
• Welding and Connections:
  • For welded flanges, high-quality control of welds is required to avoid defects such as cracks, pores, and other damages.
• Testing:
  • Flanges must undergo hydrostatic pressure tests, which exceed the operating pressure, to check the tightness and strength of the connections.
• Surface Treatment:
  • Flange surfaces must be cleaned of contaminants, rust, and other defects, and treated to prevent corrosion and improve sealing properties.

Application Areas

• Oil and Gas Industry: for transporting oil, gas, and processed products.
• Chemical Industry: for working with aggressive chemicals and liquids.
• Energy Sector: for steam pipes, heat exchange systems, and other piping networks.
• General Industrial Applications: for water supply, heating, and other engineering systems.

GOST 33259-2015 — Steel flanges for connecting pipelines, fittings, and equipment

1. Purpose

GOST 33259-2015 establishes the requirements for steel flanges used to connect pipelines, shut-off valves, and equipment. The standard regulates the main dimensions, types of sealing surfaces, materials, and quality control methods for flanges.

2. Flange Types

Depending on the method of attachment and construction, the standard includes the following types of flanges:

• Weld neck flanges (type 11) — butt-welded to the pipe;
• Flat flanges (type 01) — lap-welded to the pipe;
• Threaded flanges (type 13) — attached by a threaded connection;
• Lapped flanges (type 02) — used with weld-on rings or stubs;
• Blind flanges (type 05) — used to seal the ends of pipelines.

3. Key Technical Specifications

• Diameters: From DN 10 to DN 4000 (nominal diameters).
• Pressure Classes: From PN 2.5 to PN 250 (from 0.25 to 25 MPa).
• Materials:
  • Carbon steel (steels 20, 09G2S, and others).
  • Stainless steel (12Kh18N10T, AISI 304, 316, etc.).
  • Alloy steel (15Kh5M and other steels for operation in aggressive environments and at high temperatures).

4. Sealing Surfaces

GOST 33259-2015 describes the following types of sealing surfaces for flanges:

• Flat Face (FF) — used at low pressures.
• Raised Face (RF) — standard option for operation at medium and high pressures.
• Tongue and Groove (TG) — provides a more reliable tight connection.
• Male and Female (MF) — similar to tongue and groove, but with a different geometry.
• Ring Type Joint (RTJ) — used for ultra-high pressures.

5. Key Dimensions and Tolerances

• Bolt Hole Diameters: Depending on the nominal diameter (DN) and nominal pressure (PN).
• Flange Thickness: Depends on the pressure and diameter. For example, for DN 50 and PN 40, the flange thickness is 20 mm, and for DN 1000 and PN 2.5, it is up to 40 mm.
• Number and Size of Bolts: Increases depending on the pressure class and diameter. For example, for DN 100 and PN 10, 4 bolts with a diameter of 18 mm are provided, and for DN 1000 and PN 250 — up to 36 bolts with a diameter of 52 mm.

Dimensional Tolerances:

• Flange Thickness: ±1 mm for DN up to 600 mm, ±2 mm for DN over 600 mm.
• Flatness Deviation: up to 0.5 mm for DN up to 500 mm and up to 1 mm for DN over 500 mm.

6. Inspection and Testing

• Visual inspection — the geometry, absence of cracks and defects on the surface are checked.
• Ultrasonic testing — is used to detect internal defects in the metal.
• Mechanical tests — control of hardness, impact toughness, tensile, and other parameters.
• Dimensional control — checks the compliance of thickness, diameters, and other dimensions with the established tolerances.

7. Application

Flanges according to GOST 33259-2015 are used in the following industries:

• Oil and gas industry — connection of pipelines for transporting oil, gas, and petroleum products.
• Chemical industry — for working with aggressive environments.
• Energy industry — at thermal and nuclear power plants.
• Municipal systems — water supply and heating pipelines.

8. Advantages

• Wide range of sizes and pressures — from small to extra-large flanges.
• Versatility — the ability to work in high-temperature and aggressive environments.
• Tightness of connections — thanks to sealing surfaces of different types.
• Strength and stability — the ability to work at high pressures (up to 25 MPa) and temperatures.

GOST 12822-80 — Flat steel flanges for pipeline connections

Purpose

GOST 12822-80 establishes requirements for flat steel flanges used to connect pipelines, fittings, and process equipment. These flanges provide a reliable and tight connection and are used at various operating pressures and temperatures.

Key Technical Specifications

• Flange Type: Flat welded flange (lap welding).
• Diameters: Nominal diameters (DN) from 10 mm to 1600 mm.
• Pressure Classes: From Ру 0.1 to Ру 2.5 MPa (from 1 to 25 kgf/cm²).
• Materials: Carbon steel, low-alloy steel, stainless steel.
• Sealing Surface Type:
  • Smooth;
  • Raised face;
  • Recess;
  • Raised face and recess;
  • Tongue and groove.

Dimensions and Tolerances

• Flange Thickness: Depends on the diameter (DN) and pressure (Ру). For DN 50 mm and Ру 1 MPa, the thickness is 12 mm, and for DN 1600 mm and Ру 2.5 MPa, it is up to 40 mm.
• Bolt Hole Diameter: Regulated for each DN and Ру.
• Number and Diameter of Bolts: Depends on the diameter and pressure class. For example, for DN 50 mm and Ру 1 MPa, 4 bolts with a diameter of 14 mm are used, and for DN 1600 mm and Ру 2.5 MPa, 32 bolts with a diameter of 36 mm are used.
• Dimensional Tolerances:
  • Flange Thickness: ±1.0 mm for DN up to 600 mm, ±2.0 mm for DN over 600 mm.
  • Flatness Deviation: up to 0.5 mm for DN up to 500 mm and up to 1 mm for DN over 500 mm.

Application

Flat flanges according to GOST 12822-80 are used for installing pipelines, fittings, and equipment in systems with low and medium pressure. Main application areas:

• Oil and gas industry;
• Chemical and petrochemical industry;
• Water supply and heating systems;
• Energy and metallurgical industry.

GOST 12821-80 — Steel weld neck flanges for pipeline connections

1.Purpose

GOST 12821-80 establishes the requirements for steel weld neck flanges used to connect pipelines, fittings, and equipment. Weld neck flanges provide a reliable, tight connection at high pressures and temperatures.

2.Key Technical Specifications

• Diameters: Nominal diameters (DN) from 10 mm to 1600 mm.
• Pressure Classes: From Ру 1.0 to Ру 20.0 MPa (from 10 to 200 kgf/cm²).
• Connection Type: Butt welding.
• Materials: Carbon, low-alloy, and stainless steel.
• Sealing Surface Type:
  • Smooth;
  • Raised face and recess;
  • Tongue and groove.

3.Dimensions and Tolerances

• Neck Thickness: Depends on the pressure and nominal diameter. For DN 10 mm at Ру 1 MPa, the thickness is 16 mm, and for DN 1600 mm at Ру 20 MPa, it is up to 90 mm.
• Sealing Surface Diameter: Regulated by the tables of the standard for each DN and Ру.
• Dimensional Deviations:
• Thickness: ±1.0 mm for diameters up to 600 mm and ±2.0 mm for diameters over 600 mm.
• Flatness Deviation: For DN up to 500 mm — 0.3 mm; for DN from 500 mm and above — 0.5 mm.

4.Application

Weld neck flanges according to GOST 12821-80 are used for installing pipelines, fittings, and equipment in conditions of increased requirements for tightness and resistance to high pressures and temperatures. Used in the following industries:

• Oil and gas industry;
• Chemical industry;
• Energy sector;
• Metallurgical industry.

5.Advantages of weld neck flanges

• High strength due to the “butt welding” connection;
• Resistance to high pressures and temperatures;
• Increased tightness due to various options for sealing surfaces;
• Durability and corrosion resistance when using stainless and alloy steels.

This standard ensures the versatility and reliability of pipeline connections and is widely used in high-pressure and high-temperature industrial systems.

GOST 12820-80 — Flat steel flanges for pipeline connections

1.Purpose

GOST 12820-80 establishes the requirements for flat steel flanges used to connect pipelines, fittings, and other equipment. These flanges are used for systems with a nominal pressure from 0.1 to 2.5 MPa (1–25 kgf/cm²).

2.Key Technical Specifications

• Diameters: Nominal diameters (DN) from 10 mm to 1600 mm.
• Pressure Classes: From Ру 0.1 to Ру 2.5 MPa (from 1 to 25 kgf/cm²).
• Materials: Carbon, low-alloy, and stainless steel.
• Flange Type: Flat flange (butt-welded).
• Sealing Surface Shape: Smooth surface, tongue-and-groove, or raised face-and-recess.

3.Dimensions and Tolerances

• Flange Thickness: Depending on the diameter and pressure, the thickness varies from 12 mm to 58 mm.
• Thickness Tolerances: ±1.0 mm.
• Diameter Tolerances: For seating surfaces — ±1 mm for DN up to 500 mm and ±3 mm for DN over 500 mm.
• Flatness Deviation: For flanges with a diameter up to 500 mm — up to 0.3 mm, for flanges larger than 500 mm — up to 0.5 mm.

4.Application

GOST 12820-80 is used in the oil and gas, chemical, energy, and other industries for connecting piping systems to equipment or fittings.

The standard regulates the requirements for spectacle blind flanges (or line blinds) for use in piping systems. These flanges are intended for use in pipeline sections where it is necessary to provide the possibility of rotating the flange or blind relative to the axis of the pipe to compensate for possible axial and angular deviations. Spectacle blind flanges are widely used in pipelines where connections are needed that allow components to rotate without changing their position relative to other parts of the system.

Key characteristics and requirements of ASME B16.48 for Spectacle Blind Flanges:

• Diameters:
  • Flanges covered by this standard can be made in the range from 1/2 inch (DN 15) to 60 inches (DN 1500) and larger, depending on the pressure class and pipe diameter.
• Pressure Classes:
  • ASME B16.48 flanges can be made for pressure classes from 150 to 2500.
• Flange Types:
  • The standard describes spectacle blind flanges with the ability to rotate for connections providing mobility. These flanges can be with one hole or with several bolt holes.
• Materials:
  • Flanges can be made of various materials, including carbon steel, alloy steel, stainless steel, and other alloys, meeting the operating requirements for a specific application.
• Wall Thickness:
  • The minimum blind thickness is determined based on the pressure class and nominal diameter. For each class (150-2500), the thickness increases proportionally to the pressure and diameter.
• Dimensional Tolerances:
  • Thickness Tolerances: The permissible thickness deviation is ±0.25 mm or 1% of the nominal thickness, whichever is greater.
  • Diameter Tolerances: The tolerance on the diameter of the blind bore is usually ±1 mm for small diameters and up to ±3 mm for larger sizes.
  • Geometric Deviations: The flatness deviation should not exceed 0.3-0.5 mm for every 500 mm of diameter.

This European standard covers flanges for piping systems. It specifies requirements for flanges used to connect pipelines, valves, pumps, and other equipment, and includes standards for various pressure classes, flange types, and their materials.

Key characteristics and requirements according to EN 1759-1:

• Flange Types:
  • Weld Neck Flanges,
  • Plate Flanges,
  • Slip-On Flanges,
  • Threaded Flanges.
• Pressure Classes:
  • Flanges can be classified by pressure, for example, PN 6, PN 10, PN 16, PN 25, PN 40, etc.
  • The standard covers flanges with pressure classes up to PN 400.
• Materials:
  • Various materials are used, including carbon steel, stainless steel, and alloy steels. Materials comply with European standards for chemical composition and mechanical properties.
• Sizes:
  • Flange diameters vary depending on the type and class, ranging from DN 10 to DN 4000 (from 1/8” to 160”).
• Dimensional Tolerances:
  • The standard defines tolerances for diameter, wall thickness, hole diameter, as well as standard dimensions for each class of flange.
• Testing and Inspections:
  • Includes requirements for testing flanges for leak tightness and strength.

This European standard describes flanges used for pipeline connections. The standard covers flanges of various types and classes, including flanged flanges (e.g., weld neck flanges, slip-on flanges, threaded and lapped flanges).

Key characteristics and requirements according to EN 1092-1:

• Flange Types:
  • Weld Neck Flanges,
  • Slip-on Flanges,
  • Threaded Flanges,
  • Plate Flanges.
• Materials:
  • Carbon steel, alloy steel, stainless steel,
  • Materials comply with standards for different operating conditions.
• Diameters:
  • Flanges are available for pipe diameters from DN 10 to DN 4000 (from 1/8” to 160”).
• Pressure Classes:
  • Pressure classes from PN 2.5 to PN 400.
• Wall Thickness and Tolerances:
  • Depend on the pressure class, diameter, and type of flange, including tolerances on the flange diameter and wall thickness to ensure a tight connection.
• Additional Requirements:
  • Surface treatment (e.g., grinding and polishing),
  • Requirements for the chemical composition of materials,
  • Leak testing.

This standard is used in pipeline systems in various industries, such as the petrochemical industry, the gas industry, the energy sector, and others, where a high-quality and durable pipeline connection is required.

ASME B16.47 Series A and B are standards developed by the American Society of Mechanical Engineers (ASME) that describe requirements for large diameter flanges for use in piping systems. These standards include two different types of flanges depending on the design:

1. ASME B16.47 Series A — flanges with larger diameters and higher wall thickness, designed for use in heavy-duty applications, such as in the petrochemical and gas industry. They are often manufactured to stricter design standards and are intended for higher loads.
2. ASME B16.47 Series B — flanges with less thick walls and more lenient requirements for materials and their processing. These flanges are intended for less demanding applications where such high strength is not required, as with Series A flanges.

Diameters: Flanges according to this standard can have diameters from 12 to 60 inches for Series A and from 12 to 48 inches for Series B.

Pressure Classes: Flanges are available in pressure classes from 150 to 2500, depending on the type of flange and its application.

Materials: Flanges can be made of carbon steel, alloy steel, stainless steel, and other materials, depending on the operating conditions and requirements for corrosion resistance.

Flange Types: Include weld neck flanges, slip-on flanges, as well as lap joint and threaded flanges.

Sizes:

• Series A: 12” - 60” (305 mm - 1524 mm).
• Series B: 12” - 48” (305 mm - 1219 mm).

Wall Thickness:

• For 12” to 24” in class 150: 0.375” (9.525 mm).
• For 12” to 24” in class 2500: 1.125” (28.575 mm).
• For 30” to 48” in class 150: 0.500” (12.7 mm).
• For 30” to 48” in class 2500: 1.250” (31.75 mm).

Tolerances:

• Bore Diameter: ±0.125” (±3.175 mm).
• Flange Diameter (12” - 24”): ±0.250” (±6.35 mm); (30” - 60”): ±0.375” (±9.525 mm).
• Wall Thickness: ±0.0625” (±1.5875 mm).

ASME B16.36 standard regulates flanges intended for use in pipe, valve, pump, and other equipment connections where pressure fluctuations are possible at the connection point.

1.Types of Flanges according to ASME B16.36

• Weld Neck Flanges (WN)
  • Have a tapered conical transition to the pipe to reduce stress concentration.
  • Used for heavy-duty operating conditions and high pressures.
  • Comply with pressure classes: 300, 400, 600, 900, 1500, and 2500 psi.
• Lap Joint Flanges (LJ)
  • Not welded to the pipe but rest on a special pipe end (nipple or flanged end).
  • Facilitate installation because the flange rotates freely around the pipe.
  • Comply with pressure class: 300 psi.
• Threaded Flanges (THD)
  • A thread is cut into the inside of the flange bore for connection to the pipe.
  • Used for small-diameter pipes or when welding is not possible.
  • Comply with pressure class: 300 psi.

2.Flange Materials

Carbon, alloy, and stainless steels complying with the following standards are used to manufacture flanges according to ASME B16.36:

• ASTM A105 — carbon steel for flanges used at high temperatures.
• ASTM A182 — stainless and alloy steel.
• ASTM A350 — low-temperature carbon steel.

3.Diameters and Dimensions of Flanges according to ASME B16.36

Nominal Pipe Size (NPS): from ½” to 24” (from 15 mm to 600 mm).

Element Dimensions:

• Diameter of the nozzle (collar) bore — according to ASME B16.36.
• Thickness of the flange part, diameter of the outer edge, location and size of bolt holes — depending on the pressure class and NPS.

4.Application: Oil and gas, chemical, petrochemical, energy industries.

5.Quality Control: Visual inspection, geometry control, hydraulic testing, material verification.

ASME B16.5 Standard for Pipe Flanges and Flanged Fittings: Regulates the design, dimensions, tolerances, materials, and testing methods for flanges and flanged fittings for pipelines and equipment used in the petrochemical, gas, and energy industries. Key characteristics of the standard include:

1. Flange Types

• Plate Flanges, Flat Face (FF)
• Weld Neck (WN)
• Threaded (THD)
• Slip-On (SO)
• Blind (BL)
• Lap Joint (LJ)

2. Diameters and Pressure Classes

• Nominal Pipe Sizes (NPS): from ½” to 24”
• Pressure Classes: 150, 300, 400, 600, 900, 1500, 2500 (in pounds per square inch, psi)

3. Flange Materials

The standard allows the use of carbon, stainless, and alloy steels, as well as non-ferrous metals. The most commonly used are:

• ASTM A105 (carbon steel)
• ASTM A182 (stainless and alloy steel)
• ASTM A350 (low-temperature steels)
• ASTM B462 (non-ferrous metals)

4. Design Features

• Types of jointing faces:
  • Raised Face (RF)
  • Flat Face (FF)
  • Ring Type Joint (RTJ)
• Gasket types: gaskets made of metal, graphite, and composite materials are used to ensure tightness.

5. Mechanical Properties and Quality Control

• Tightness control: hydraulic and pneumatic tests.
• Mechanical properties: strength and ductility depend on the material (for example, for ASTM A105, the tensile strength is 485 MPa, the yield strength is 250 MPa).
• Corrosion resistance: materials resistant to corrosive environments (e.g., H₂S) are used, which complies with NACE MR0175.

6. Application

ASME B16.5 flanges are used in:

• Oil and gas industry (main pipelines, refinery equipment)
• Petrochemical industry (reactors, heat exchangers)
• Energy (steam and hot water boilers, turbines)

The international standard that regulates the requirements for equipment and components used in the oil and gas industry. This standard covers flanges, valves, fittings, and other equipment elements operating under high pressure.

Scope of Application

• API 6A applies to the following elements:
• Flanges and connecting elements;
• Valves (valves, gates);
• Crosses and tees;
• Components and equipment parts for subsea oil and gas production.

Materials and their Control

• Materials must be resistant to aggressive environments (H₂S, CO₂) and corrosion.
• High-strength carbon and alloy steels are used with control of impurity content.
• Mechanical properties control is applied:
  • Tensile Strength (UTS): 550–950 MPa (80,000–137,800 psi)
  • Yield Strength (YS): 355–758 MPa (51,500–110,000 psi)
  • Hardness: no more than 22 HRC or 250 HB for resistance to cracking in H₂S environments (in accordance with NACE MR0175)
  • Operating temperature classes: from -46°C to +180°C depending on the requirements of the classes (L, U, X, Y)

Types of Flanges (by construction)

• Weld Neck Flanges — for high pressures and temperatures.
• Blind Flanges — for sealing pipelines.
• RTJ Flanges (Ring Type Joint) — to ensure tightness under pressure.
• End Flanges — for connections at the ends of pipelines.

Pressure Ratings

API 6A classifies flanges and elements by pressure levels (PSL — Product Specification Level) from 2000 psi to 20,000 psi.

• 2000, 3000, 5000, 10,000, 15,000, 20,000 psi — depending on operating conditions.

Types of Sealing Connections

• RTJ (Ring Type Joint) — metal rings for high pressures and temperatures.
• RF (Raised Face) — sealing surface with a raised face for additional tightness.

Testing and Quality Control

• Hydraulic testing — checking for leaks under pressure.
• Non-destructive testing (NDT) — ultrasonic and radiographic diagnostics of welds and surfaces.
• Tests for resistance to H₂S exposure (hydrogen sulfide environment) according to NACE MR0175/ISO 15156.

Product Specification Levels (PSL 1 - PSL 4)

• PSL 1 — basic level, the simplest with minimal requirements.
• PSL 2 — increased requirements for the quality of materials and control methods.
• PSL 3 — strict quality control and complete test documentation.
• PSL 4 — maximum requirements for subsea production systems (Subsea).

MSS SP-75 is a standard developed by the Manufacturers Standardization Society (MSS) that regulates the production and technical requirements for flanges and pipeline connections intended for use in systems subjected to high pressures.

Purpose

MSS SP-75 is used to ensure standard characteristics and quality of flanges, connections and fittings used in pipelines that are operated under high pressure conditions. It aims to standardize the dimensions, materials and testing of these elements to ensure their reliability and durability in harsh operating conditions.

Key Technical Specifications

• Types of Flanges and Fittings:
  • Flanges: flat face, weld neck, slip-on.
  • Fittings: reducers, elbows, tees and other connecting elements.
• Materials:
  • Carbon steels (e.g. ASTM A105, ASTM A350 LF2).
  • Stainless steels (e.g. ASTM A182 F304, ASTM A182 F316).
  • Alloy steels (e.g. ASTM A182 F11, ASTM A182 F22).
• Operating Pressure:
  • The MSS SP-75 standard focuses on flanges and connections operating at pressures ranging from 150 to 2500 pounds per square inch (psi), which corresponds to various pressure classes, including classes 150, 300, 600, 900, 1500 and 2500.
• Diameters:
  • The diameters of the flanges range from 1/2 inch (DN 15) to 60 inches (DN 1500) and larger, depending on the type of flange and its purpose.
• Wall Thickness and Dimensions:
  • The standard defines the exact dimensions of the flanges, including the wall thickness, the diameter of the holes and other geometrical parameters, which must comply with the established norms to ensure the tightness and strength of the connections.

Key Requirements

• Material Quality
  • Materials must comply with ASTM standards and have confirmed quality certificates.
• Welding and Connections
  • Welded flanges must be manufactured using technologies that ensure the strength and tightness of the connections, without welding defects.
• Testing
  • Flanges and fittings must undergo a hydrostatic pressure test exceeding the operating pressure to ensure their tightness and safety.
• Surface Treatment
  • The surfaces of the flanges and fittings must be treated to prevent corrosion and improve the sealing properties.

Application Areas

• Oil and gas industry: for the transportation of oil, gas and processed products.
• Chemical industry: for working with aggressive chemicals.
• Energy sector: for pipelines operating in steam and heat exchange systems.
• General industrial applications: for water supply, heating and other pipeline systems.

EN 10253-1, EN 10253-2, EN 10253-3 and EN 10253-4 are European standards that regulate the production of fittings for piping systems operating under pressure.

Purpose

Fittings according to EN 10253 standards are designed to connect pipes in systems operating under pressure. They provide a smooth change in direction, diameter or configuration of the pipeline, minimizing pressure losses and ensuring reliable connections.

Key Technical Specifications

1. Classification of standards:
   • EN 10253-1: Fittings of non-alloy and ferritic steels without specific inspection requirements.
   • EN 10253-2: Fittings of non-alloy and ferritic steels with specific inspection requirements.
   • EN 10253-3: Fittings of austenitic stainless steels without specific inspection requirements.
   • EN 10253-4: Fittings of austenitic stainless steels with specific inspection requirements.
2. Diameter range: from DN 15 to DN 1200.
   • Wall thickness: corresponds to the pipes to which the fittings are connected, and depends on the design pressure and temperature.
   • Working pressure: up to 100 bar and higher depending on the type of steel and wall thickness.
3. Materials:
   • Carbon and alloy steels (e.g. P235GH, P265GH, 16Mo3).
   • Stainless steels (e.g. X2CrNi18-9, X5CrNiMo17-12-2).
4. Tolerances:
   • Outer diameter: ±1%.
   • Length: ±2 mm.
   • Ovality: no more than 3%.

Key requirements

• Compliance with the chemical composition and mechanical properties of steel.
• High quality welds (for welded fittings).
• Absence of surface defects (cracks, pits, pores).
• Conducting hydrostatic and mechanical tests (for EN 10253-2 and EN 10253-4 fittings).

DIN 2616-1 and DIN 2616-2 are standards that regulate the manufacture of welded reducers for pipelines used in systems operating under pressure. Reducers serve to connect pipes of different diameters, ensuring a smooth change in flow cross-section.

Purpose

DIN 2616 reducers are used to connect pipes of different diameters, ensuring minimal hydraulic losses and smooth flow of the medium. They are used in pipelines in the oil and gas, chemical, energy and other industries.

Key Technical Specifications

1. Types of Reducers:
   • DIN 2616-1: Concentric Reducers (pipe axes coincide).
   • DIN 2616-2: Eccentric Reducers (pipe axes are offset).
2. Diameters:
   • Nominal diameter (DN): from 10 mm to 1200 mm.
   • Larger end diameter (D1): from 21.3 mm to 1420 mm.
   • Smaller end diameter (D2): from 17.2 mm to 1320 mm.
3. Wall Thickness:
   • The minimum wall thickness corresponds to the thickness of the pipes to which the reducer is connected, and depends on the operating pressure and temperature.
4. Reducer Length:
   • Determined by the standard and varies depending on the nominal diameter and type of reducer.
5. Tolerances:
   • Outer diameter: ±1% of the nominal diameter, but not less than ±0.5 mm.
   • Ovality: no more than 3% of the outer diameter.
   • Reducer length: ±2 mm.
   • Axis offset (for eccentric reducers): no more than 1 mm.
6. Materials:
   • Carbon steels (e.g. P235GH, P265GH).
   • Stainless steels (e.g. X5CrNi18-10).
   • Alloy steels (e.g. 13CrMo4-5).
7. Testing:
   • Hydrostatic test at a pressure exceeding the operating pressure by 1.5 times.
   • Weld inspection (ultrasonic, radiographic).

DIN 2615-1 and DIN 2615-2 are standards that regulate the production of welded tees for pipelines used in systems under pressure. They ensure standardization of geometry, materials and quality control methods for tees, which makes them a reliable element of piping systems.

Purpose

DIN 2615 tees are designed for branching pipelines, connecting main pipes with branches. They are used in systems operating under high pressure and temperature, such as oil and gas, chemical, energy and construction industries.

Key Technical Specifications

1. Types of Tees:
   • DIN 2615-1: Tees with equal diameters of all three openings (straight tees).
   • DIN 2615-2: Tees with different diameters (reducing tees).
2. Diameters:
   • Nominal diameter (DN): from 10 mm to 1200 mm.
3. Wall thickness:
   • The wall thickness must correspond to the thickness of the pipe to which the tee is connected.
4. Tolerances:
   • Outer diameter: ±1% of the nominal diameter, but not less than ±0.5 mm.
   • Length of straight sections: ±2 mm.
   • Ovality: no more than 3% of the outer diameter.
   • Angular deviations: ±0.5° for straight tees.
5. Materials:
   • Carbon steels (e.g. P235GH, P265GH).
   • Stainless steels (e.g. X5CrNi18-10).
   • Alloy steels (e.g. 13CrMo4-5).
6. Testing:
   • Hydrostatic test at a pressure exceeding the operating pressure by 1.5 times.
   • Non-destructive testing of welds (ultrasonic, radiographic).

DIN 2605-1 and DIN 2605-2 are standards that regulate the manufacture of bent pipe bends used in systems operating under pressure. These standards cover geometric parameters, technical requirements and tolerances to ensure the reliability, durability and safety of fittings.

Purpose

Elbows manufactured according to DIN 2605 are used to change the direction of flow in pipelines. They are widely used in the oil and gas, chemical, energy and construction industries.

Key Technical Specifications

1. Types of Elbows:
   • DIN 2605-1: Elbows with calculated bending radius (standard).
   • DIN 2605-2: Elbows with individually specified parameters (e.g. for high pressures).
2. Bending Radius:
   • Short radius (R = 1×DN).
   • Long radius (R = 1.5×DN).
3. Diameters:
   • Nominal diameter (DN): from 10 mm to 1200 mm.
4. Wall thickness:
   • The minimum wall thickness of the elbows corresponds to the wall thickness of the pipes to which they are connected, and depends on the operating pressure and temperature.
5. Dimensional Tolerances:
   • Outer diameter: ±1% of the nominal diameter, but not less than ±0.5 mm.
   • Ovality: no more than 3% of the outer diameter.
   • Bending radius: ±2% of the nominal value.
   • Bend angle: ±0.5° for DN ≤ 250 mm, ±1° for DN > 250 mm.
6. Materials:
   • Carbon steels (e.g. P235GH, P265GH).
   • Stainless steels (e.g. X5CrNi18-10).
   • Alloy steels (e.g. 13CrMo4-5).
7. Testing:
   • Hydrostatic test at a pressure exceeding the working pressure by 1.5 times.
   • Quality control of welds (ultrasound, X-ray).

DIN 2619 is a German industrial standard that regulates the requirements for the production of welded pipe fittings, such as elbows, tees, reducers and other components used in piping systems.

Purpose: designed for the production of welded fittings used in systems operating under pressure.

Materials: covers the use of carbon, alloy and stainless steels, which provide resistance to corrosion and mechanical stress.

Application areas: widely used in the oil and gas, chemical, energy, shipbuilding and other industries.

Pressure and temperature: fittings must withstand a design pressure of up to 100 bar and temperatures up to +600 °C (depending on the material).

Fitting Diameters:

• Nominal diameter (DN): from 10 mm to 1200 mm.
• Outer diameter (OD): depends on the pipe standard to which the fitting is connected

Wall thickness:

• Complies with pipe standards (e.g. DIN EN 10216-2 for seamless pipes).
• The minimum wall thickness of the fitting must be at least the wall thickness of the pipe being connected.

Outer Diameter (OD) Tolerances:

• For DN ≤ 400 mm: ±1% of the nominal diameter, but not less than ±0.5 mm.
• For DN > 400 mm: ±1.5% of the nominal diameter.

ASME B16.28 — Standard for Wrought Steel Buttwelding Short Radius Elbows and Returns

Purpose

ASME B16.28 covers the requirements for wrought steel buttwelding elbows for piping systems that are used in high-pressure and high-temperature systems. This standard applies to elbows made of carbon and alloy steel with 90° and 45° angles, designed for butt welding.

Types and Shapes of Elbows

• 90° Elbows — for a sharp change in the direction of the pipeline.
• 45° Elbows — for a smooth change in the direction of the pipeline.

Key Technical Specifications

• Diameters: from ½” to 24” (from 15 mm to 610 mm).
• Wall thickness: complies with the requirements for pipes with nominal thicknesses SCH 5, SCH 10, SCH 40, SCH 80, etc.
• Connection type: butt welding (BUTTWELD).
• Pressure classes: pressure depends on the wall thickness and diameter, in accordance with specifications for high temperatures and pressures.
• Materials: carbon and alloy steel, including steel for operation in aggressive and high-temperature environments.

Key Requirements and Tolerances

• Geometric Dimensions: strict tolerances on angles (45°, 90°) and radii of elbows (usually R = 1D or 1.5D, where D is the pipe diameter).
• Length Tolerance: depending on the diameter and angle of the elbow.
• Surface Quality: elbows must be free from cracks, pits and other surface defects.
• Quality Control: each elbow undergoes non-destructive testing (UT, VT) to check for defects.

Application Area

• Oil and gas industry: high pressure and temperature pipelines.
• Chemical industry: pipelines with aggressive media.
• Energy industry: steam piping and heating network systems.
• Shipbuilding: water supply and fuel pipeline systems.

Advantages of the ASME B16.28 Standard

• Quality Assurance: strict requirements for geometric dimensions and mechanical characteristics.
• Reliability: seamless elbows are resistant to loads from pressure and temperature.
• Application Flexibility: the possibility of using for pipes of different thickness and pressure class.

ASME B16.28 is a standard that ensures high reliability and durability of elbows for industrial pipelines, especially in conditions of increased pressure and temperature.

ASME B16.11 — Standard for Forged Fittings, Socket-Welding and Threaded

Purpose

ASME B16.11 establishes the requirements for small diameter fittings (up to 4 inches) for threaded and socket-welding connections. These fittings are used to create leak-proof connections in pipelines operating under high pressure and at high temperatures.

Types of Fittings

• Threaded Fittings:
  • Couplings (connecting pipes of the same diameter).
  • Elbows (90° and 45°) — changing the direction of the pipeline.
  • Tees (straight and reducing) — creating branches.
  • Plugs (plugs and caps) — sealing the ends of the pipeline.
  • Nipples and adapters — connecting various elements of the pipeline.
• Socket-Welding Fittings:
  • Elbows (90°, 45°).
  • Tees (straight and reducing).
  • Couplings and Half-Couplings.
  • Crosses — creating cross connections.
  • Caps (end caps).

Key Technical Specifications

• Diameters: from 1/8” to 4” (from 6 mm to 100 mm).
• Pressure classes: 2000, 3000, 6000 and 9000 (depending on the type of fitting and application).
• Wall thickness: corresponds to the parameters of the pipeline and pressure class.
• Materials: carbon, alloy and stainless steel.

Tolerances and Accuracy

• Thread: according to ASME B1.20.1 (NPT thread).

Fitting Geometry: strict tolerances on angles, diameters and dimensions of sockets and threads.

Surface quality: fittings should not have cracks, pits and other defects.

Application

• Oil and gas industry.
• Oil refineries (refineries).
• High pressure systems.
• Pipelines for aggressive media and high temperatures.

Advantages of ASME B16.11 Standard

• Ensuring reliable connections in high pressure systems.
• Resistance to vibrations and shock loads.
• Ease of installation and dismantling during maintenance.

ASME B16.11 is widely used for small diameter fittings, providing ease of installation and tightness of connections in high pressure systems, including at oil and gas, chemical and energy facilities.

ASME B16.9 — Standard for Pipe Fittings

Purpose

ASME B16.9 establishes the requirements for seamless and welded steel pipe fittings. These fittings are used for connecting pipes, changing their direction or diameter, and plugging the ends of pipelines.

Types of Fittings

• Elbows (45°, 90°, 180°) — changing the direction of the pipeline.
• Tees (straight and reducing) — creating branches in the pipeline.
• Reducers (concentric and eccentric) — connecting pipes of different diameters.
• Caps — hermetically sealing the end of the pipeline.

Key Technical Specifications

1. Diameters: from 1/2” to 48” (from 15 mm to 1200 mm).
2. Wall thickness: corresponds to pipes according to ASME B36.10 and B36.19 standards.
3. Materials: carbon, alloy, and stainless steel.
4. Pressure classes: from Class 150 to Class 2500 (depending on the applicable pipe standard).

Accuracy and Tolerances

1. Ovality: ovality is allowed no more than 1% of the outer diameter of the pipe.
2. Wall thickness: the minimum wall thickness must comply with the pipeline standard.
3. Dimensions and length of straight sections: strict tolerances on length and dimensions are defined for tees, elbows, and reducers.

Application

• Oil and gas industry.
• Oil refineries (refineries).
• Energy and chemical industry.
• High pressure and temperature pipeline systems.

ASME B16.9 is an internationally recognized standard that is used worldwide for the production of fittings that provide a reliable connection of pipelines in harsh operating conditions.

A state standard regulating the requirements for cold-deformed seamless pipes made of corrosion-resistant (stainless) steel, intended for operation in aggressive environments, high temperatures, and pressure. This standard is used in the petrochemical, chemical, energy, and food industries.

Types of pipes and production methods

• Type of pipes - cold-deformed seamless pipes (in contrast to hot-deformed pipes according to GOST 9940-81).
• Production process - pipes are obtained by cold deformation followed by heat treatment, which ensures their accurate dimensions and high performance characteristics.
• Material - corrosion-resistant stainless steels of the following grades:
  • 08Х18Н10Т
  • 12Х18Н10Т
  • 10Х17Н13М2Т
• Other alloys with the addition of nickel, chromium, and molybdenum to increase resistance to corrosion and temperature effects.
• Dimensions and tolerances
  • Outer diameter of pipes - from 5 mm to 273 mm.
  • Wall thickness - from 0.2 mm to 22 mm (depending on the type of pipe and application).
  • Pipe length - multiple sizes or measured length from 1 m to 11 m.
  • Tolerances on diameter and wall thickness - minimal tolerances are provided for cold-deformed pipes, which makes them accurate and suitable for precision applications.
• Mechanical properties
  • Strength and ductility - pipes provide high strength under loads and maintain ductility.
  • Hardness - for various steel grades, the hardness limit is controlled, for example, for 12Х18Н10Т - no more than 200 HB.
  • Temperature resistance - pipes retain their strength characteristics at high temperatures (from -70°C to +600°C).

Quality control and testing

The production process of pipes according to GOST 9941-81 is accompanied by strict quality control:

• Tensile test - checks yield strength and tensile strength.
• Hydrostatic test - pipes are tested under water or air pressure to check for leak-tightness.
• Bending test - checks the ductility of the pipe and resistance to bending without cracking and deformation.
• Non-destructive testing - ultrasonic or magnetic flaw detection is performed to identify hidden defects.
• Control of geometric parameters - measurements of the outer diameter, wall thickness, and curvature of the pipe.

A state standard establishing requirements for seamless pipes made of corrosion-resistant (stainless) steel, used for various technical purposes, including operation under high pressure, at high temperatures, and in aggressive environments.

Key provisions and characteristics:

Purpose and scope

• Pipes according to GOST 9940-81 are used in the following industries:
• Oil and gas industry (transportation of aggressive substances);
• Chemical and petrochemical industry (aggressive environments and high temperatures);
• Energy sector (pipelines for steam and hot water);
• Food and pharmaceutical industry (where hygienic safety and corrosion resistance are required).

Material: Pipes are made of stainless steels of various grades, for example, 08Х18Н10Т, 12Х18Н10Т, 10Х17Н13М2Т, and others.

Dimensions and allowable deviations

• Pipe diameter - from 5 mm to 273 mm (for hot-deformed pipes) and from 5 mm to 219 mm (for cold-deformed pipes).
• Wall thickness - from 0.5 mm to 22 mm (depending on the production method and application area).
• Pipe length - multiple sizes or measured length from 1.5 m to 12 m.
• Ovality and curvature - regulated by tolerances on ovality and deviations from straightness.

Mechanical properties

Mechanical properties depend on the steel grade and heat treatment method. Approximate parameters:

• Tensile strength (σв) - from 490 to 590 MPa (depending on the steel grade).
• Elongation (δ) - from 35% to 40%.
• Hardness - no more than 200 HB (for austenitic stainless steels).

Heat treatment

• To improve mechanical properties and eliminate internal stresses, pipes are subjected to quenching and tempering.
• Heat treatment of welds is possible to improve the metal structure.

Quality control and testing

The production process of pipes according to GOST 9940-81 is accompanied by strict quality control:

• Tensile test - checks yield strength and tensile strength.
• Bending test - the pipe must withstand bending without failure.
• Hydrostatic test - checks leak-tightness under pressure.
• Impact toughness test - especially important at low temperatures.
• Geometry control - measurements of the outer diameter, wall thickness, and curvature of the pipe.
• Non-destructive testing - ultrasonic testing to detect hidden defects.

GOST 31447-2012 is a Russian standard that establishes technical conditions for steel welded pipes for main gas pipelines, oil pipelines, and oil product pipelines. This standard sets requirements for the quality, materials, manufacturing methods, testing, marking, and packaging of steel welded pipes intended for the construction of main pipelines transporting gas, oil, and oil products under high pressure.

Main provisions of GOST 31447-2012:

Application area:

• Oil and gas industry: main oil pipelines, oil pipelines at fields, oil product pipelines.

Pipe dimensions:

• Diameter range: from 114 mm to 1420 mm and more (outer diameter).
• Wall thickness: varies depending on the pipe diameter and working pressure specified in the design documentation.
• Pipe length: unmeasured length, measured length, multiple measured length.

Materials:

• Carbon and low-alloy steels: (09G2S, 17G1S, 13ХФА, and others).

The choice of steel grade depends on operating conditions, working pressures, ambient temperature, and corrosion resistance requirements.

Main requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics and reduce strength are not allowed on the surface of the pipes.
• Special attention is paid to the preparation of the surface for the application of protective coatings.
• The weld must be strong, tight, and free of defects, ensuring the reliability and durability of the connection.
• Automated welding methods are used (e.g., automatic submerged arc welding).
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters, taking into account the accuracy requirements for operation in oil pipelines.
• Pipes must meet the requirements for tensile strength, yield strength, elongation, and impact toughness.
• Special attention is paid to impact toughness at low temperatures, which is critical for operation in harsh climatic conditions.

Quality Control:

• Visual inspection: checking the surface of pipes and welds for defects.
• Dimensional measurement: control of diameter, wall thickness, curvature, and other geometric parameters.
• Non-destructive testing: ultrasonic testing of welds (mandatory), radiographic testing (if necessary).
• Hydraulic tests: pressure tests to check strength and leak-tightness.
• Mechanical tests: tensile tests, bending tests, impact toughness tests.
• Control of the chemical composition of steel.

Protective coatings:

• Internal and external anticorrosion coatings (epoxy, polyurethane, etc.) are used to protect against corrosion and increase service life.

GOST 3262-75 is a Russian standard that establishes technical conditions for steel water and gas pipes (WGP). This standard defines requirements for quality, materials, dimensions, manufacturing methods, tests, marking, and packaging of steel welded and seamless pipes intended for use in water supply and gas supply systems, as well as for other purposes. This standard is widely used in construction, housing and communal services, and other industries.

Main provisions of GOST 3262-75:

Application area:

• Water supply (cold and hot water supply).
• Gas supply (low pressure).
• Heating (heating systems).
• Other engineering systems (e.g., fire protection systems).

Types of pipes:

• Pipes with threads (cut or rolled) at the ends.
• Pipes without threads.

Pipe dimensions:

• Diameter range: nominal bore (DN): from 6 mm (1/8 inch) to 100 mm (4 inches).
• Wall thickness: light pipes, ordinary pipes, reinforced pipes.
• Wall thickness varies depending on the nominal bore and pipe type.
• Pipe length: unmeasured length, measured length, multiple measured length.

Materials:

• Carbon steel (St1, St2, St3).

The choice of steel grade depends on the required strength, corrosion resistance, and other factors.

Main Requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics are not allowed on the surface of the pipes.
• Individual, minor defects are allowed if they do not exceed the established norms.
• The thread must be clean, without defects, and ensure a leak-proof connection.
• Requirements for the accuracy of the cut thread are established for threaded pipes.
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters.
• Pipes must meet the requirements for tensile strength, yield strength, and elongation.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of nominal bore, diameter, wall thickness, length.
• Hydraulic test: pressure test to check strength and leak-tightness.
• Thread strength test (for threaded pipes).

GOST 8734-75 is a Russian standard that establishes the range of sizes for steel seamless cold-deformed pipes. The standard defines the dimensions, wall thickness, and other parameters of pipes manufactured by cold deformation and having no weld seam. These pipes are characterized by higher dimensional accuracy and surface quality compared to hot-deformed pipes. It is used in various industries, such as mechanical engineering, instrument engineering, the aviation industry, and others where high accuracy and quality of pipes are required.

Main provisions of GOST 8734-75:

Application area:

• Mechanical engineering (machine parts, hydraulic systems, bearings).
• Aviation industry (pipelines, structural elements).
• Instrument engineering (instrument elements, housings).
• Oil and gas industry (special pipelines).
• Automotive industry (suspension components, steering).

Pipe dimensions:

• Diameter range: from 5 mm to 250 mm (outer diameter).
• Wall thickness: from 0.3 mm to 25 mm (depending on the outer diameter).
• Pipe length: unmeasured length (from 1.5 to 11.5 meters), measured length, multiple measured length.

Materials:

• Carbon steels (10, 20, 35, 45, etc.).
• Alloy steels (15Х, 20Х, 30Х, 40Х, etc.).
• The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Cracks, films, laps, scratches, and other defects that impair performance characteristics are not allowed on the surface of the pipes.
• Pipes must meet the requirements for ovality, curvature, and wall thickness variation.
• Pipes must meet the requirements for tensile strength, yield strength, elongation, and reduction of area.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of diameter, wall thickness, curvature, and ovality.
• Mechanical tests: tensile tests, flattening tests, expanding tests to check strength and ductility.
• Non-destructive testing: ultrasonic testing to detect internal defects (if necessary).
• Metallographic analysis to control microstructure.

GOST 8732-78 is a Russian standard that establishes the range of sizes for steel seamless hot-deformed pipes. The standard defines the dimensions, wall thickness, and other parameters of pipes manufactured by hot deformation and having no weld seam. It is used in various industries, such as oil and gas, chemical, mechanical engineering, and others.

Main provisions of GOST 8732-78:

Application area:

• Mechanical engineering (machine elements, parts, bearings).
• Oil and gas industry (pipelines, equipment).
• Chemical industry (pipelines, apparatus).
• Energy sector (boilers, heat exchangers, pipelines).
• Construction (metal structures).

Pipe dimensions:

• Diameter range: from 20 mm to 530 mm (outer diameter).
• Wall thickness: from 2.5 mm to 75 mm (depending on the outer diameter).
• Pipe length: unmeasured length (from 4 to 12 meters), measured length, multiple measured length.

Materials:

• Carbon steels (St2, St3, 20, etc.).
• Alloy steels (30ХГСА, 40Х, etc.).
• The choice of steel grade depends on the required properties (strength, corrosion resistance, heat resistance) and operating conditions.

Main requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics are not allowed on the surface of the pipes.
• Individual, minor defects (for example, small scratches) are allowed if they do not exceed the established norms and do not affect strength.
• Pipes must meet the requirements for ovality, curvature, wall thickness variation, and other geometric parameters.
• Pipes must meet the requirements for tensile strength, yield strength, elongation, and impact toughness.
• Mechanical properties depend on the steel grade and heat treatment regime.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of diameter, wall thickness, and length.
• Mechanical tests: tensile tests, flattening tests, bending tests, impact toughness tests (if necessary).
• Ultrasonic testing to detect internal defects (if necessary).

GOST 10705-80 is a Russian standard that establishes technical conditions for steel electric-welded straight-seam pipes intended for general construction use. The standard applies in construction, mechanical engineering, and other industries where general-purpose electric-welded straight-seam pipes are used.

Main provisions of GOST 10705-80:

Application area:

• Construction (metal structures, scaffolding).
• Mechanical engineering (elements of machines and equipment).
• Oil and gas industry (pipelines).
• Housing and communal services (water supply, heating, gas supply systems).
• Agriculture (irrigation systems).

Materials:

• Carbon steels (St3, 10, 20, etc.).
• Low-alloy steels (09G2S, etc.).
• The choice of steel grade depends on the required properties and operating conditions.

Dimensions:

• Diameter range: from 10 mm to 530 mm.
• Wall thickness: from 1 mm to 8 mm.
• Pipe length: unmeasured length (from 4 to 12 meters), measured length, multiple measured length.

Main Requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics and reduce strength are not allowed on the surface of the pipes.
• The weld must be tight, strong, and free of defects that affect its load-bearing capacity.
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters.

Testing:

• Hydraulic tests - are carried out for pipes intended for operation under pressure, and must withstand the hydraulic pressure established by the standard without signs of leakage or destruction.
• Tensile tests - are carried out to determine the mechanical properties of steel.
• Bending or flattening tests - are carried out to check the plasticity of steel and the quality of the weld (may not be carried out for all steel grades).

Quality Control:

• Visual inspection: checking the surface of pipes and welds for defects.
• Dimensional control: measuring diameter, wall thickness, curvature.
• Weld control: ultrasonic testing is used to detect internal defects.

GOST 10704-91 is a Russian standard that establishes the range of sizes for steel electric-welded straight-seam pipes. The standard defines the dimensions, wall thickness, and other parameters of pipes manufactured by electric welding and having a straight longitudinal seam. It is used in various industries, such as construction, mechanical engineering, the oil and gas industry, and others.

Key characteristics:

Application area:

• Construction (metal structures, scaffolding).
• Mechanical engineering (elements of machines and equipment).
• Oil and gas industry (pipelines, transportation systems).
• Housing and communal services (water supply, heating systems).
• Agriculture (irrigation systems).

Pipe dimensions:

• Outer diameters of pipes in the range from 10 mm to 1420 mm.
• The wall thickness of the pipes varies depending on the diameter, but is usually in the range from 1 mm to 32 mm.
• The length of the pipes is usually from 4 to 12 meters, but may be different as agreed with the customer. Pipes can be made in measured, unmeasured, and multiple measured lengths.

Materials:

• Carbon steels (e.g., St3, 20).
• Low-alloy steels (e.g., 09G2S, 17G1S).

The choice of steel grade is determined by the requirements for strength, weldability, and corrosion resistance.

Main requirements:

• Cracks, delaminations, laps, films, and other defects that impair performance characteristics are not allowed on the surface of the pipes.
• The weld must be strong, tight, and free of defects that reduce its load-bearing capacity.
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters.

Testing:

• Pipes must withstand hydraulic pressure exceeding the operating pressure.
• Mechanical tests (tensile, bending, etc.) are carried out to control the conformity of the mechanical properties of steel to the requirements of the standard.

Quality control:

• Quality control of the weld is carried out (for example, by ultrasonic method, radiography).
• Geometric dimensions and surface quality are controlled.

GOST 30245-2003 is a Russian standard that establishes technical conditions for steel bent closed welded square and rectangular profiles for building structures. This standard defines requirements for the quality, materials, manufacturing methods, testing, marking, and packaging of steel bent welded profiles of square and rectangular cross-section, intended for use in building structures. These profiles are made by bending a steel sheet followed by welding the seam.

Main provisions of GOST 30245-2003:

Application area:

• The standard applies to steel bent closed welded square and rectangular profiles intended for use in building structures.
• These profiles are used as elements of building frames, columns, beams, trusses, ties, and other load-bearing and enclosing structures.

Types of profiles:

• Square profiles.
• Rectangular profiles.

Profile dimensions:

• Square profiles: side dimensions from 40x40 mm to 400x400 mm.
• Rectangular profiles: side dimensions from 40x20 mm to 500x400 mm.
• Wall thickness: from 2 mm to 12 mm (depending on the profile size).
• Pipe length: unmeasured length, measured length, multiple measured length.

Materials:

• Carbon steels (St3ps/sp, St3Gps/sp).
• Low-alloy steels (09G2S).

The choice of steel grade depends on the required properties and operating conditions, including loads, climatic conditions, and weldability requirements.

Main requirements:

• The dimensions of the cross-section must comply with the requirements of the standard.
• Radii of curvature of corners, flatness of faces, and other parameters must be within tolerances.
• Pipes must meet the requirements for curvature.
• Profiles must meet the requirements for yield strength, tensile strength, and elongation.
• The weld must be strong, tight, free of defects (cracks, pores, lack of fusion), ensuring the reliability and durability of the structure.
• Requirements for the preparation of edges for welding and for welding technology.
• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics are not allowed on the surface of the profiles.
• Minor defects not exceeding the established norms are allowed.

Quality Control:

• Visual inspection: checking the surface for defects, control of geometric dimensions.
• Dimensional measurement: control of profile dimensions, wall thickness, curvature, and other parameters.
• Mechanical tests: tensile tests, bending tests, flattening tests to check the compliance of mechanical properties with the requirements of the standard.
• Non-destructive testing: ultrasonic testing of the weld (if necessary).
• Impact bending test (if necessary).

GOST 8645-68 is a Russian standard that establishes the range of sizes for steel rectangular tubes. The standard defines the dimensions, wall thickness, and other parameters of pipes having a rectangular cross-section and manufactured by various methods (welded, seamless). These pipes are used in construction, mechanical engineering, furniture production, and other industries for the manufacture of various structures, frames, supports, and other elements where greater bending stiffness is required in one direction.

Main provisions of GOST 8645-68:

Application area:

• Construction (metal structures, frames of buildings and structures).
• Mechanical engineering (elements of machines and equipment).
• Furniture production.
• Advertising structures.
• Automotive industry.

Pipe dimensions:

• Width (a): from 15 mm to 230 mm.
• Height (b): from 10 mm to 100 mm.
• Wall thickness (s): from 1 mm to 8 mm.
• Pipe length: unmeasured length, measured length, multiple measured length.

Materials:

• Carbon steels (St1, St2, St3, and others).
• Low-alloy steels (09G2S, 17G1S, and others).
• The choice of steel grade depends on the required properties and operating conditions.

General requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics are not allowed on the surface of the pipes.
• Individual, minor defects (for example, small scratches) are allowed if they do not exceed the established norms.
• Pipes must meet the requirements for deviation from straightness, twist, and other geometric parameters.
• Pipes must meet the requirements for tensile strength, yield strength, and elongation.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of width, height, wall thickness, length.
• Mechanical tests: tensile tests, flattening tests.

GOST 8639-82 is a Russian standard that establishes the range of sizes for steel square tubes. The standard defines the dimensions, wall thickness, and other parameters of pipes having a square cross-section and manufactured by various methods (welded, seamless). These pipes are used in construction, mechanical engineering, furniture production, and other industries for the manufacture of various structures, frames, supports, and other elements.

Main provisions of GOST 8639-82:

Application area:

• Construction (metal structures, frames of buildings and structures).
• Mechanical engineering (elements of machines and equipment).
• Furniture production.
• Automotive industry.
• Agriculture.

Pipe dimensions:

• Square side (a): from 10 mm to 180 mm.
• Wall thickness (s): from 0.8 mm to 14 mm.
• Pipe length: unmeasured length, measured length, multiple measured length.

Materials:

• Carbon steels (St1, St2, St3, and others).
• Low-alloy steels (09G2S, 17G1S, and others).
• The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics are not allowed on the surface of the pipes.
• Individual, minor defects (for example, small scratches) are allowed if they do not exceed the established norms.
• Pipes must meet the requirements for deviation from straightness, twist, and other geometric parameters.
• Pipes must meet the requirements for tensile strength, yield strength, and elongation.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of the square side, wall thickness, length.
• Mechanical tests: tensile tests, flattening tests.

DIN 28179-2007 is a German standard (Deutsches Institut für Normung) that specifies the technical delivery conditions for steel U-tubes intended for use in shell-and-tube heat exchangers. The standard establishes requirements for materials, dimensions, manufacturing quality, testing, and marking of these tubes, ensuring their reliability and durability in heat exchange equipment.

Key Provisions:

Application Areas

• Oil refining industry
• Chemical industry
• Energy sector
• Cryogenic engineering
• Food industry

Main Technical Characteristics

• Type of tubes: U-shaped steel tubes (U-tubes) for shell-and-tube heat exchangers.
• Size range (diameter and wall thickness): the standard covers a wide range of tube outer diameters (e.g., from 12 mm to 50 mm and more) and wall thicknesses depending on pressure requirements and operating conditions.
• Tube length: tube length varies depending on the heat exchanger design and can be specified in the order.
• Materials:
  • Carbon steels (e.g., P235GH, P265GH).
  • Alloy steels (e.g., 16Mo3, 13CrMo4-5).
  • Stainless steels (e.g., 1.4301, 1.4404). The choice of material depends on the working environment and the required corrosion resistance.
• U-bend geometry: bend radius, straight section length, and other geometric parameters must comply with the requirements of the standard and heat exchanger drawings.

Main Requirements

• Quality of materials: materials must comply with the steel grades specified in the standard, have quality certificates, and meet the requirements for chemical composition and mechanical properties.
• Manufacturing and tolerances: tubes must be manufactured by cold or hot deformation methods, ensuring uniform wall thickness and absence of defects.
• Tolerances on dimensions (diameter, wall thickness, length) must comply with the requirements of the standard.
• Heat treatment: tubes must undergo heat treatment (e.g., annealing) to relieve internal stresses and improve mechanical properties.
• Quality control: non-destructive testing (e.g., ultrasonic testing, eddy current testing) to detect defects (cracks, delaminations) in the tube material, hydraulic tests for strength and leak-tightness.
• Surface treatment: the tube surface must be clean, free of burrs, scale, rust, and other defects.
• Marking: each tube must be marked with information about the manufacturer, material, dimensions, and batch number.

As a rule, they are manufactured according to individual drawings and customer specifications. General standards can be applied to the original pipe from which the U-shaped pipe is manufactured.

GOST 5520-79 is a Russian standard that regulates technical conditions for carbon, low-alloy, and alloy steel thick plates for boilers and vessels operating under pressure. The standard describes the requirements for the chemical composition, mechanical properties, surface quality, and other characteristics of steel plates used for the manufacture of boilers, vessels, apparatus, and other welded structures operating under pressure. It is used in various industries, such as power engineering, chemical engineering, petrochemical engineering, and others.

Main provisions of GOST 5520-79:

Application area:

• Boiler construction: production of boilers of various types.
• Production of pressure vessels: tanks, cylinders, apparatus.
• Chemical and petrochemical industry: apparatus operating with aggressive media.
• Energy sector: heat exchangers, steam generators.

Types of steel:

• Carbon steels: (e.g., 20K, 22K).
• Low-alloy steels: (e.g., 16GS, 17GS, 09G2S).
• Alloy steels: (e.g., 12XM, 15XM).

The choice of steel grade depends on the required strength, heat resistance, corrosion resistance, weldability, and other factors determined by the operating conditions of the equipment.

Sheet dimensions:

• The standard does not establish specific sheet dimensions but defines the requirements for the accuracy of sheet manufacturing in terms of thickness, width, and length.
• The thickness of the sheets is usually from 4 mm to 160 mm and more.
• The sheet dimensions can be different and are determined by the customer’s requirements.

Main requirements:

• The content of carbon, manganese, silicon, sulfur, phosphorus, and other elements that determine the properties of steel is strictly regulated.
• Requirements for tensile strength, yield strength, elongation, and reduction of area are established.
• Special attention is paid to impact toughness at low temperatures (for equipment operating in cold climates).
• The heat treatment modes (normalization, tempering) necessary to achieve the required mechanical properties are indicated.
• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics are not allowed on the surface of the sheets.
• Steels must have good weldability, ensuring the strength and reliability of welded joints.
• Special welding materials and technologies are used for welding.

Quality Control:

• Control of chemical composition: analysis of the chemical composition of steel.
• Mechanical tests: tensile tests, bending tests, impact toughness tests.
• Visual inspection: checking the surface of the sheets for defects.
• Ultrasonic testing: for detecting internal defects (if necessary).

GOST 10885-85 is a Russian standard that establishes technical conditions for hot-rolled thick plate steel for welded structures. It defines requirements for the chemical composition, mechanical properties, surface quality, testing methods, and other parameters applicable to sheet steel used in the production of welded structures operating under load and in various climatic conditions.

Main provisions of GOST 10885-85:

Application area:

• The standard applies to sheets of carbon, low-alloy, and alloy steel intended for the manufacture of welded structures.
• It covers sheets with a thickness of 4 to 160 mm and more, depending on the steel grade.
• Sheets can be used to manufacture structures operating at various temperatures, loads, and environmental conditions.

Materials:

• Carbon steels: (St3, St4, etc. - with varying degrees of deoxidation).
• Low-alloy steels: (09G2, 09G2S, 10KhSND, 15KhSND, 10KhNDP, etc.).

The choice of steel grade depends on the operating conditions (working pressure, temperature, corrosion resistance, weldability, etc.).

Dimensions:

• Sheet thickness: from 4 mm and more (depending on the steel grade).
• Sheet length and width are established by the standard depending on the thickness and steel grade.

Main Properties:

• The content of carbon, manganese, silicon, sulfur, phosphorus, chromium, nickel, copper, and other elements affecting the properties of steel is regulated.
• The content of harmful impurities (sulfur and phosphorus) is limited.
• Requirements are established for tensile strength, yield strength, elongation, reduction of area, and impact toughness (including at low temperatures).
• The grain size is normalized for some steel grades.
• Surface defects (dents, scratches, scale, etc.) are allowed if they do not exceed the established norms.
• The surface quality must meet the requirements for welding.
• Steels must have good weldability, ensuring the strength and reliability of welded joints.
• The carbon equivalent characterizing weldability is normalized for some steel grades.

Quality Control:

• Control of chemical composition: analysis of the chemical composition of steel.
• Mechanical tests: tensile tests, impact toughness tests (including at low temperatures).
• Visual inspection: checking the surface of the sheets for defects.
• Ultrasonic testing (if necessary).

Acceptance:

• Sheets are accepted in batches.
• The quality of the sheets is assessed based on the results of the control carried out in accordance with the requirements of the standard.

There is no universal GOST for finned pipes. Requirements are usually described in the customer's specifications. Standards for pipes used as a base are applied (for example, GOST 8732-78, GOST 10705-80).

GOST 9.301-86 is a Russian standard that is part of the Unified System of Corrosion and Aging Protection of Materials and Products (ESZKS). It establishes general requirements and methods for corrosion and aging protection for metallic and non-metallic inorganic coatings. The standard covers a wide range of protection methods, including electroplating, paint and varnish coatings, chemical oxidation, phosphating, and other types of protective coatings used to protect products from corrosion.

Main provisions of GOST 9.301-86:

Application area:

• Mechanical engineering.
• Instrument engineering.
• Automotive industry.
• Aviation industry.
• Construction.
• Electrical engineering.
• Radio electronics.
• Production of consumer goods.

Types of coatings:

• Electroplating (zinc plating, chrome plating, nickel plating, cadmium plating, tin plating, etc.).
• Paint and varnish coatings (enamels, varnishes, primers, paints).
• Chemical coatings (oxidation, phosphating).
• Metallization coatings.
• Inorganic non-metallic coatings.

Requirements for the quality of coatings:

• GOST 9.301-86 establishes requirements for the quality of coatings, including thickness, adhesion (bond strength to the base material), porosity, corrosion resistance, and appearance.
• It defines methods for controlling the quality of coatings, such as measuring thickness, adhesion tests, corrosion resistance tests in salt spray, visual inspection, etc.
• The quality of the coating must protect the product from corrosion and other negative effects during the specified service life.

Testing methods:

• Adhesion tests (lattice methods, pull-off, scribe tests).
• Hardness tests (pencil hardness, Brinell hardness, etc.).
• Corrosion resistance tests (in salt spray chambers, humidity chambers, sulfur dioxide chambers, etc.).
• Appearance assessment.
• Measurement of coating thickness (microscopic method, eddy current method, magnetic induction method).

GOST 10705-80 is a Soviet and Russian standard that establishes technical conditions for electric-welded straight-seam steel pipes. It defines requirements for geometric parameters, mechanical properties, surface quality, and testing methods of these pipes, intended for use in various industries. This standard is widely used for the production and application of electric-welded pipes, particularly in construction, mechanical engineering, the oil and gas industry, and other fields.

Main provisions of GOST 10705-80:

Application area:

• Construction (metal structures, scaffolding).
• Mechanical engineering (elements of machines and equipment).
• Oil and gas industry (pipelines).
• Housing and communal services (water supply, heating, gas supply systems).
• Agriculture (irrigation systems).

Dimensions and Allowable Deviations

• Diameter range: from 10 mm to 530 mm (outer diameter).
• Wall thickness: from 1 mm to 8 mm.
• Pipe length: unmeasured length (from 4 to 12 meters), measured length, multiple measured length.

Material

• Carbon steels (St3, 10, 20, etc.).
• Low-alloy steels (09G2S, etc.).
• The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics and reduce strength are not allowed on the surface of the pipes.
• The weld must be tight, strong, and free of defects that affect its load-bearing capacity.
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters.

Testing:

• Hydraulic test: pipes must withstand the hydraulic pressure specified in the standard.
• Mechanical tests: tensile tests, bending tests to verify the conformity of the mechanical properties of steel to the requirements of the standard.

Quality Control:

• Visual inspection: checking the surface of pipes and welds for defects.
• Dimensional control: measuring diameter, wall thickness, curvature.
• Weld control: ultrasonic testing is used to detect internal defects.

GOST 8734-75 is a Russian standard that establishes the range of sizes for steel seamless cold-deformed pipes. The standard defines the dimensions, wall thickness, and other parameters of pipes manufactured by cold deformation and having no weld seam. These pipes are characterized by higher dimensional accuracy and surface quality compared to hot-deformed pipes. It is used in various industries, such as mechanical engineering, instrument engineering, the aviation industry, and others where high accuracy and quality of pipes are required.

Main provisions of GOST 8734-75:

Application area:

• Mechanical engineering (machine parts, hydraulic systems, bearings).
• Aviation industry (pipelines, structural elements).
• Instrument engineering (elements of instruments, housings).
• Oil and gas industry (special pipelines).
• Automotive industry (suspension components, steering).

Pipe dimensions:

• Diameter range: from 5 mm to 250 mm (outer diameter).
• Wall thickness: from 0.3 mm to 25 mm (depending on the outer diameter).
• Pipe length: unmeasured length (from 1.5 to 11.5 meters), measured length, multiple measured length.

Materials:

• Carbon steels (10, 20, 35, 45, etc.).
• Alloy steels (15Kh, 20Kh, 30Kh, 40Kh, etc.).
• The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Cracks, films, laps, scratches, and other defects that impair performance characteristics are not allowed on the surface of the pipes.
• Pipes must meet the requirements for ovality, curvature, and wall thickness variation.
• Pipes must meet the requirements for tensile strength, yield strength, elongation, and reduction of area.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of diameter, wall thickness, curvature, and ovality.
• Mechanical tests: tensile tests, flattening tests, flaring tests to check strength and ductility.
• Non-destructive testing: ultrasonic testing to detect internal defects (if necessary).
• Metallographic analysis to control microstructure.

GOST 9.301-86 is a Russian standard that is part of the Unified System of Corrosion and Aging Protection of Materials and Products (ESZKS). It establishes general requirements and methods for corrosion and aging protection for metallic and non-metallic inorganic coatings. The standard covers a wide range of protection methods, including electroplating, paint and varnish coatings, chemical oxidation, phosphating, and other types of protective coatings used to protect products from corrosion.

Main provisions of GOST 9.301-86:

Application area:

• Mechanical engineering.
• Instrument engineering.
• Automotive industry.
• Aviation industry.
• Construction.
• Electrical engineering.
• Radio electronics.
• Production of consumer goods.

Types of coatings:

• Electroplating (zinc plating, chrome plating, nickel plating, cadmium plating, tin plating, etc.).
• Paint and varnish coatings (enamels, varnishes, primers, paints).
• Chemical coatings (oxidation, phosphating).
• Metallization coatings.
• Inorganic non-metallic coatings.

Requirements for the quality of coatings:

• GOST 9.301-86 establishes requirements for the quality of coatings, including thickness, adhesion (bond strength to the base material), porosity, corrosion resistance, and appearance.
• It defines methods for controlling the quality of coatings, such as measuring thickness, adhesion tests, corrosion resistance tests in salt spray, visual inspection, etc.
• The quality of the coating must protect the product from corrosion and other negative effects during the specified service life.

Testing methods:

• Adhesion tests (lattice methods, pull-off, scribe tests).
• Hardness tests (pencil hardness, Brinell hardness, etc.).
• Corrosion resistance tests (in salt spray chambers, humidity chambers, sulfur dioxide chambers, etc.).
• Appearance assessment.
• Measurement of coating thickness (microscopic method, eddy current method, magnetic induction method).

GOST 10705-80 is a Soviet and Russian standard that establishes technical conditions for electric-welded straight-seam steel pipes. It defines requirements for geometric parameters, mechanical properties, surface quality, and testing methods of these pipes, intended for use in various industries. This standard is widely used for the production and application of electric-welded pipes, particularly in construction, mechanical engineering, the oil and gas industry, and other fields.

Main provisions of GOST 10705-80:

Application area:

• Construction (metal structures, scaffolding).
• Mechanical engineering (elements of machines and equipment).
• Oil and gas industry (pipelines).
• Housing and communal services (water supply, heating, gas supply systems).
• Agriculture (irrigation systems).

Dimensions and Allowable Deviations

• Diameter range: from 10 mm to 530 mm (outer diameter).
• Wall thickness: from 1 mm to 8 mm.
• Pipe length: unmeasured length (from 4 to 12 meters), measured length, multiple measured length.

Material

• Carbon steels (St3, 10, 20, etc.).
• Low-alloy steels (09G2S, etc.).

The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics and reduce strength are not allowed on the surface of the pipes.
• The weld must be tight, strong, and free of defects that affect its load-bearing capacity.
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters.

Testing:

• Hydraulic test: pipes must withstand the hydraulic pressure specified in the standard.
• Mechanical tests: tensile tests, bending tests to verify the conformity of the mechanical properties of steel to the requirements of the standard.

Quality Control:

• Visual inspection: checking the surface of pipes and welds for defects.
• Dimensional control: measuring diameter, wall thickness, curvature.
• Weld control: ultrasonic testing is used to detect internal defects.

GOST 8734-75 is a Russian standard that establishes the range of sizes for steel seamless cold-deformed pipes. The standard defines the dimensions, wall thickness, and other parameters of pipes manufactured by cold deformation and having no weld seam. These pipes are characterized by higher dimensional accuracy and surface quality compared to hot-deformed pipes. It is used in various industries, such as mechanical engineering, instrument engineering, the aviation industry, and others where high accuracy and quality of pipes are required.

Main provisions of GOST 8734-75:

Application area:

• Mechanical engineering (machine parts, hydraulic systems, bearings).
• Aviation industry (pipelines, structural elements).
• Instrument engineering (elements of instruments, housings).
• Oil and gas industry (special pipelines).
• Automotive industry (suspension components, steering).

Pipe dimensions:

• Diameter range: from 5 mm to 250 mm (outer diameter).
• Wall thickness: from 0.3 mm to 25 mm (depending on the outer diameter).
• Pipe length: unmeasured length (from 1.5 to 11.5 meters), measured length, multiple measured length.

Materials:

• Carbon steels (10, 20, 35, 45, etc.).
• Alloy steels (15Kh, 20Kh, 30Kh, 40Kh, etc.).
• The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Cracks, films, laps, scratches, and other defects that impair performance characteristics are not allowed on the surface of the pipes.
• Pipes must meet the requirements for ovality, curvature, and wall thickness variation.
• Pipes must meet the requirements for tensile strength, yield strength, elongation, and reduction of area.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of diameter, wall thickness, curvature, and ovality.
• Mechanical tests: tensile tests, flattening tests, flaring tests to check strength and ductility.
• Non-destructive testing: ultrasonic testing to detect internal defects (if necessary).
• Metallographic analysis to control microstructure.

GOST 9.301-86 is a Russian standard that is part of the Unified System of Corrosion and Aging Protection of Materials and Products (ESZKS). It establishes general requirements and methods for corrosion and aging protection for metallic and non-metallic inorganic coatings. The standard covers a wide range of protection methods, including electroplating, paint and varnish coatings, chemical oxidation, phosphating, and other types of protective coatings used to protect products from corrosion.

Main provisions of GOST 9.301-86:

Application area:

• Mechanical engineering.
• Instrument engineering.
• Automotive industry.
• Aviation industry.
• Construction.
• Electrical engineering.
• Radio electronics.
• Production of consumer goods.

Types of coatings:

• Electroplating (zinc plating, chrome plating, nickel plating, cadmium plating, tin plating, etc.).
• Paint and varnish coatings (enamels, varnishes, primers, paints).
• Chemical coatings (oxidation, phosphating).
• Metallization coatings.
• Inorganic non-metallic coatings.

Requirements for the quality of coatings:

• GOST 9.301-86 establishes requirements for the quality of coatings, including thickness, adhesion (bond strength to the base material), porosity, corrosion resistance, and appearance.
• It defines methods for controlling the quality of coatings, such as measuring thickness, adhesion tests, corrosion resistance tests in salt spray, visual inspection, etc.
• The quality of the coating must protect the product from corrosion and other negative effects during the specified service life.

Testing methods:

• Adhesion tests (lattice methods, pull-off, scribe tests).
• Hardness tests (pencil hardness, Brinell hardness, etc.).
• Corrosion resistance tests (in salt spray chambers, humidity chambers, sulfur dioxide chambers, etc.).
• Appearance assessment.
• Measurement of coating thickness (microscopic method, eddy current method, magnetic induction method).

GOST 10705-80 is a Soviet and Russian standard that establishes technical conditions for electric-welded straight-seam steel pipes. It defines requirements for geometric parameters, mechanical properties, surface quality, and testing methods of these pipes, intended for use in various industries. This standard is widely used for the production and application of electric-welded pipes, particularly in construction, mechanical engineering, the oil and gas industry, and other fields.

Main provisions of GOST 10705-80:

Application area:

• Construction (metal structures, scaffolding).
• Mechanical engineering (elements of machines and equipment).
• Oil and gas industry (pipelines).
• Housing and communal services (water supply, heating, gas supply systems).
• Agriculture (irrigation systems).

Dimensions and Allowable Deviations

• Diameter range: from 10 mm to 530 mm (outer diameter).
• Wall thickness: from 1 mm to 8 mm.
• Pipe length: unmeasured length (from 4 to 12 meters), measured length, multiple measured length.

Material

• Carbon steels (St3, 10, 20, etc.).
• Low-alloy steels (09G2S, etc.).

The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Defects (cracks, delaminations, laps, films, etc.) that impair performance characteristics and reduce strength are not allowed on the surface of the pipes.
• The weld must be tight, strong, and free of defects that affect its load-bearing capacity.
• Pipes must meet the requirements for ovality, curvature, and other geometric parameters.

Testing:

• Hydraulic test: pipes must withstand the hydraulic pressure specified in the standard.
• Mechanical tests: tensile tests, bending tests to verify the conformity of the mechanical properties of steel to the requirements of the standard.

Quality Control:

• Visual inspection: checking the surface of pipes and welds for defects.
• Dimensional control: measuring diameter, wall thickness, curvature.
• Weld control: ultrasonic testing is used to detect internal defects.

GOST 8734-75 is a Russian standard that establishes the range of sizes for steel seamless cold-deformed pipes. The standard defines the dimensions, wall thickness, and other parameters of pipes manufactured by cold deformation and having no weld seam. These pipes are characterized by higher dimensional accuracy and surface quality compared to hot-deformed pipes. It is used in various industries, such as mechanical engineering, instrument engineering, the aviation industry, and others where high accuracy and quality of pipes are required.

Main provisions of GOST 8734-75:

Application area:

• Mechanical engineering (machine parts, hydraulic systems, bearings).
• Aviation industry (pipelines, structural elements).
• Instrument engineering (elements of instruments, housings).
• Oil and gas industry (special pipelines).
• Automotive industry (suspension components, steering).

Pipe dimensions:

• Diameter range: from 5 mm to 250 mm (outer diameter).
• Wall thickness: from 0.3 mm to 25 mm (depending on the outer diameter).
• Pipe length: unmeasured length (from 1.5 to 11.5 meters), measured length, multiple measured length.

Materials:

• Carbon steels (10, 20, 35, 45, etc.).
• Alloy steels (15Kh, 20Kh, 30Kh, 40Kh, etc.).
• The choice of steel grade depends on the required properties and operating conditions.

Main requirements:

• Cracks, films, laps, scratches, and other defects that impair performance characteristics are not allowed on the surface of the pipes.
• Pipes must meet the requirements for ovality, curvature, and wall thickness variation.
• Pipes must meet the requirements for tensile strength, yield strength, elongation, and reduction of area.

Quality Control:

• Visual inspection: checking the surface of pipes for defects.
• Dimensional measurement: control of diameter, wall thickness, curvature, and ovality.
• Mechanical tests: tensile tests, flattening tests, flaring tests to check strength and ductility.
• Non-destructive testing: ultrasonic testing to detect internal defects (if necessary).
• Metallographic analysis to control microstructure.

GOST 24890-81 is a Russian standard that establishes technical requirements for welded pipes made of titanium and titanium alloys, intended for use in various industries where high strength characteristics, corrosion resistance, and low weight are required.

Main provisions of GOST 24890-81:

Application area:

• Aviation industry (hydraulic systems, air ducts, structural elements).
• Chemical industry (pipelines for aggressive media, heat exchangers, reactors).
• Shipbuilding (pipelines, hull elements).
• Medical equipment (implants, instruments).
• Cryogenic engineering.
• Energy sector.
• Other industries where high corrosion resistance and strength with low weight are required.

Materials:

• Titanium alloys (VT1-0, VT6, VT14, OT4, OT4-1, etc.).
• Commercially pure titanium (VT1-0).

The choice of alloy depends on the required strength characteristics, corrosion resistance, weldability, and operating conditions.

Dimensions and range of sizes:

• Diameter range: the outer diameter specifies a range, for example, from 6 mm to 114 mm and more.
• Wall thickness: specifies a range, usually from 0.5 mm to 3 mm, depending on the pipe diameter.
• Pipe length: unmeasured length, measured length, multiple measured length.

Main requirements:

• Cracks, delaminations, laps, films, and other defects that affect performance characteristics and strength are not allowed on the surface of the pipes.
• Minor defects (scratches, scratches) are allowed if they do not exceed the established norms.
• The weld must be tight, strong, without defects (cracks, pores, lack of fusion). It must ensure tightness and meet strength requirements.
• Special welding materials and technologies (gas tungsten arc welding) are used for welding.
• Pipes must meet the requirements for ovality, curvature, wall thickness variation, and other geometric parameters.
• The limits of deviation for diameter, wall thickness, and length are indicated.
• Pipes must meet the requirements for tensile strength, yield strength, and elongation.
• The minimum values of mechanical properties are indicated, depending on the alloy grade.
• Pipes must withstand tests for flattening, expansion, flanging (if provided for by the design).
• The weld is tested for tension and bending.
• Special tests for corrosion resistance in certain media may be provided.

Control and Testing Methods:

• Visual inspection.
• Measurement of geometric dimensions.
• Mechanical tests (tensile, flattening, flaring, bending of the weld).
• Non-destructive testing (ultrasonic testing - UT, radiographic testing - RT of the weld).
• Leak tightness testing (pneumatic or hydraulic tests).
• Determination of chemical composition.
• Metallographic analysis (for microstructure control of the weld and base metal).

Marking:

• The pipes must have clear and durable marking containing information about the manufacturer, alloy grade, dimensions, and other parameters.

GOST 22897-86 is a Russian standard that establishes the technical conditions for seamless cold-deformed pipes made of titanium-based alloys, intended for use in various industries where high strength characteristics, corrosion resistance, and light weight are required.

Main provisions of GOST 22897-86:

Application area:

• Aviation industry (hydraulic systems, fuel pipelines).
• Chemical industry (pipelines for aggressive media, heat exchangers).
• Shipbuilding (pipelines, heat exchangers, hull parts).
• Medical equipment (implants, instruments).
• Cryogenic engineering.
• Other industries where high strength, light weight, and corrosion resistance are required.

Materials:

• Commercially pure titanium (VT1-0, VT1-00): high corrosion resistance and ductility.
• Titanium-based alloys (VT6, OT4, VT14, and others): higher strength, but may have lower ductility and corrosion resistance than pure titanium.

Dimensions and range of sizes:

• Defines the range of outer diameters and wall thicknesses of pipes.
• Establishes dimensional tolerances (diameter, wall thickness, length).
• Regulates ovality, wall thickness variation, curvature, and other geometric parameters.

Mechanical properties:

• Tensile strength (σв): Depends on the alloy, but on average ranges from 300 to 900 MPa.
• Yield strength (σт): Also depends on the alloy and can range from 200 to 800 MPa.
• Elongation (δ): Can vary from 15% to 30% and above, depending on the alloy and heat treatment.

Welding:

• Gas tungsten arc welding (GTAW/TIG) is used to protect the weld from oxidation.
• Thorough edge preparation and surface cleaning are required.
• Welding modes and selection of welding materials (filler rods) are regulated.
• Special attention is paid to the quality control of the weld.

Control methods and tests:

• Visual inspection.
• Measurement of geometric dimensions.
• Mechanical tests (tensile, flattening, flaring).
• Non-destructive testing (ultrasonic testing - UT, eddy current testing - ET).
• Determination of chemical composition.
• Metallographic analysis (for microstructure control).
• Corrosion resistance tests (if necessary, according to individual methods).

Marking:

• The pipes must have clear and durable marking containing information about the manufacturer, alloy grade, dimensions, and other parameters.

GOST 492-2006 is an interstate standard that establishes technical conditions for nickel, nickel alloys, and semi-finished products made from them. It defines requirements for the chemical composition, mechanical properties, surface quality, testing methods, and other parameters of nickel and its alloys, as well as for the manufacturing, marking, packaging, and transportation of these materials. The standard applies to a wide range of products, including sheets, strips, ribbons, wire, rods, pipes, and forgings.

Main provisions:

Application area:

• Chemical industry (apparatus, containers, pipelines operating in aggressive environments).
• Energy (heat exchangers, steam generators, turbines).
• Electrical engineering (electrical contacts, resistive elements).
• Aerospace industry (engine parts, structures).
• Medical equipment (implants, instruments).
• Instrument engineering.
• Radio electronics.

Materials:

• Nickel (N0, N1, N2, N3, N4).
• Nickel alloys (KhN78T, KhN70Yu, KhN60VT, KhN35VT, etc.).

(The choice of material grade depends on the required strength characteristics, corrosion resistance, heat resistance, and other properties).

Types of products:

• Sheets.
• Strips.
• Ribbons.
• Wire.
• Rods.
• Pipes.
• Forgings.

Main requirements

Chemical composition:

• The content of nickel and other elements (iron, copper, manganese, silicon, sulfur, carbon, chromium, titanium, aluminum, etc.) must meet the requirements of the standard for each alloy grade.
• The content of impurities is normalized.

Mechanical properties:

• Tensile strength.
• Yield strength.
• Elongation.
• Hardness.

The minimum values of mechanical properties are indicated depending on the alloy grade and delivery condition (annealed, work-hardened, etc.).

Surface quality:

• Absence of cracks, delaminations, scale, rust, and other defects affecting performance characteristics.
• Minor defects (scratches, scratches) are allowed, provided they meet the requirements of the standard.

Manufacturing accuracy: Deviations from nominal dimensions are normalized (thickness, width, diameter, length).

Testing:

• Tensile tests (to determine mechanical properties).
• Hardness tests.
• Bend tests (for wire, ribbon).
• Corrosion resistance tests (depending on the intended use).

Quality control:

• Visual inspection: checking the surface of products for defects.
• Measurement of dimensions: control of product dimensions.
• Mechanical tests: tensile, hardness, bend tests.
• Control of chemical composition: analysis of the chemical composition of the material.
• Corrosion resistance tests (if necessary).

GOST 17217-2018 is an interstate standard that establishes technical specifications for pipes made of copper-nickel alloy grade MZH 5-1. It defines requirements for manufacturing, dimensions, surface quality, chemical composition, mechanical properties, testing methods, and quality control of these pipes. Pipes made of MZH 5-1 alloy are widely used in shipbuilding, the chemical industry, energy, and other industries where high corrosion resistance is required, especially in seawater.

Main provisions of GOST 17217-2018:

Alloy grade: MZH 5-1 (Copper-Nickel-Iron).

Dimensions:

• Diameter range: outer diameter - (specifies a range, for example, from 6 mm to 219 mm and more).
• Wall thickness: specifies a range, for example, from 0.5 mm to 10 mm and more, depending on the pipe diameter.
• Pipe length: unmeasured length, measured length, multiple measured length.

Types of pipes:

• Cold-deformed.
• Hot-deformed.

Main requirements:

• The content of copper, nickel, iron, and other elements must meet the requirements of the standard for MZH 5-1 alloy.
• The content of impurities (lead, zinc, sulfur, phosphorus, etc.) is strictly regulated.
• The minimum values of mechanical properties are indicated, depending on the material condition (annealed, work-hardened).
• Cracks, delaminations, blisters, laps, and other defects affecting performance characteristics are not allowed on the surface of the pipes.
• Minor defects (scratches, scratches) are allowed if they do not exceed the established norms.
• Pipes must meet the requirements for ovality, curvature, wall thickness variation, and other geometric parameters.
• The limits of deviation for diameter, wall thickness, and length are indicated.
• Pipes must withstand tests for flattening, expansion, flanging (if provided for by the design).

Quality control:

• Visual inspection: checking the surface of pipes for defects.
• Measurement of dimensions: control of diameter, wall thickness, curvature.
• Mechanical tests: tensile tests, flattening, expansion.
• Non-destructive testing: eddy current testing (to detect surface defects), ultrasonic testing (to detect internal defects).
• Control of chemical composition: analysis of the chemical composition of the alloy.

Marking: The pipes must have marking containing information about the manufacturer, alloy grade, dimensions, batch number, and other parameters.

GOST 17217-2018 is an interstate standard that establishes technical specifications for pipes made of copper-nickel alloy grade MZH 5-1. It defines requirements for manufacturing, dimensions, surface quality, chemical composition, mechanical properties, testing methods, and quality control of these pipes. Pipes made of MZH 5-1 alloy are widely used in shipbuilding, the chemical industry, energy, and other industries where high corrosion resistance is required, especially in seawater.

Main provisions of GOST 17217-2018:

Alloy grade: MZH 5-1 (Copper-Nickel-Iron).

Dimensions:

• Diameter range: outer diameter - (specifies a range, for example, from 6 mm to 219 mm and more).
• Wall thickness: specifies a range, for example, from 0.5 mm to 10 mm and more, depending on the pipe diameter.
• Pipe length: unmeasured length, measured length, multiple measured length.

Types of pipes:

• Cold-deformed.
• Hot-deformed.

Main requirements:

• The content of copper, nickel, iron, and other elements must meet the requirements of the standard for MZH 5-1 alloy.
• The content of impurities (lead, zinc, sulfur, phosphorus, etc.) is strictly regulated.
• The minimum values of mechanical properties are indicated, depending on the material condition (annealed, work-hardened).
• Cracks, delaminations, blisters, laps, and other defects affecting performance characteristics are not allowed on the surface of the pipes.
• Minor defects (scratches, scratches) are allowed if they do not exceed the established norms.
• Pipes must meet the requirements for ovality, curvature, wall thickness variation, and other geometric parameters.
• The limits of deviation for diameter, wall thickness, and length are indicated.
• Pipes must withstand tests for flattening, expansion, flanging (if provided for by the design).

Quality control:

• Visual inspection: checking the surface of pipes for defects.
• Measurement of dimensions: control of diameter, wall thickness, curvature.
• Mechanical tests: tensile tests, flattening, expansion.
• Non-destructive testing: eddy current testing (to detect surface defects), ultrasonic testing (to detect internal defects).
• Control of chemical composition: analysis of the chemical composition of the alloy.

Marking: The pipes must have marking containing information about the manufacturer, alloy grade, dimensions, batch number, and other parameters.

GOST 492-2006 is an interstate standard that establishes technical specifications for nickel, nickel alloys, and semi-finished products made from them. It defines requirements for the chemical composition, mechanical properties, surface quality, testing methods, and other parameters of nickel and its alloys, as well as for the manufacturing, marking, packaging, and transportation of these materials. The standard applies to a wide range of products, including sheets, strips, ribbons, wire, rods, pipes, and forgings.

Main provisions:

Application area:

• Chemical industry (apparatus, containers, pipelines operating in aggressive environments).
• Energy (heat exchangers, steam generators, turbines).
• Electrical engineering (electrical contacts, resistive elements).
• Aerospace industry (engine parts, structures).
• Medical equipment (implants, instruments).
• Instrument engineering.
• Radio electronics.

Materials:

• Nickel (N0, N1, N2, N3, N4).
• Nickel alloys (KhN78T, KhN70Yu, KhN60VT, KhN35VT, etc.).

(The choice of material grade depends on the required strength characteristics, corrosion resistance, heat resistance, and other properties).

Types of products:

• Sheets.
• Strips.
• Ribbons.
• Wire.
• Rods.
• Pipes.
• Forgings.

Main requirements

Chemical composition:

• The content of nickel and other
• elements (iron, copper, manganese, silicon, sulfur, carbon, chromium, titanium, aluminum, etc.) must meet the requirements of the standard for each alloy grade.
• The content of impurities is normalized.

Mechanical properties:

• Tensile strength.
• ii. Yield strength.
• Elongation.
• Hardness.

The minimum values of mechanical properties are indicated depending on the alloy grade and delivery condition (annealed, work-hardened, etc.).

Surface quality:

• Absence of cracks, delaminations, scale, rust, and other defects affecting performance characteristics.
• Minor defects (scratches, scratches) are allowed, provided they meet the requirements of the standard.

Manufacturing accuracy: Deviations from nominal dimensions are normalized (thickness, width, diameter, length).

Testing:

• Tensile tests (to determine mechanical properties).
• Hardness tests.
• Bend tests (for wire, ribbon).
• Corrosion resistance tests (depending on the intended use).

Quality control:

• Visual inspection: checking the surface of products for defects.
• Measurement of dimensions: control of product dimensions.
• Mechanical tests: tensile, hardness, bend tests.
• Control of chemical composition: analysis of the chemical composition of the material.
• Corrosion resistance tests (if necessary).

DIN 933 is a German standard “Hexagon Head Bolts with Full Thread.” It defines the construction, dimensions, and requirements for hexagon head bolts that have a thread along the entire length of the shank. This standard is one of the most common in mechanical engineering, construction, and other industries for creating universal and reliable connections.

Main Provisions:

Application Area:

• Mechanical engineering: joining parts and assemblies of machines and mechanisms where a full thread is required for reliable fixation.
• Construction: fastening elements of metal and wooden structures.
• Instrument engineering: fastening parts in instruments and equipment.
• Automotive industry: assembly of automobiles.
• Other industries: for a wide range of general-purpose connections.

Main Technical Characteristics:

• Bolt type: hexagon head bolt.
• Thread type: metric thread, profile in accordance with ISO 262.
• Thread size (d): usually from M1.6 to M52. The range depends on the specific version of the standard and the manufacturer.
• Thread pitch (P): determined by the metric thread standard (usually ISO 261, ISO 262). Both coarse and fine thread pitches are provided for.
• Bolt length (l): determined by the user depending on the connection requirements and is selected from the preferred range of lengths.
• Thread length (b): for DIN 933 bolts, the thread runs along the entire length of the shank (full thread), so only the overall length of the bolt (l) is specified.
• “Across flats” dimension (s): the size of the hexagon head used to tighten the bolt. Depends on the thread diameter.
• Head height (k): the height of the head.
• Materials: carbon steel, alloy steel, stainless steel (A2, A4), brass, aluminum, and others.
• Strength classes: depending on the material and purpose, DIN 933 bolts are produced with various strength classes, for example:
  • Carbon steel: 5.6, 8.8, 10.9, 12.9
  • Stainless steel: A2-70, A4-70, A2-80, A4-80
• Tolerances: comply with ISO 4759-1.
• Thread: metric (ISO 261, ISO 262).
• Coatings: may have various protective coatings to increase corrosion resistance (e.g., zinc, nickel, chrome).

Main Requirements:

• Construction and dimensions: the bolt must comply with all requirements for dimensions and shape specified in the DIN 933 standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Mechanical properties: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.
• Marking: must contain information about the strength class and the manufacturer’s trademark.

DIN 931 is a German standard “Hexagon Head Bolts with Partial Thread.” It defines the construction, dimensions, and requirements for hexagon head bolts that have a partial thread on the shank. This standard is widely used in mechanical engineering, construction, and other industries to create reliable connections.

Main Provisions:

Application Area:

• Mechanical engineering: joining parts and assemblies of machines and mechanisms.
• Construction: fastening elements of metal and wooden structures.
• Instrument engineering: fastening parts in instruments and equipment.
• Automotive industry: assembly of automobiles.
• Other industries: for a wide range of general-purpose connections.

Main Technical Characteristics:

• Bolt type: hexagon head bolt.
• Thread type: metric thread, profile in accordance with ISO 262.
• Thread size (d): usually from M1.6 to M64. The range depends on the specific version of the standard and the manufacturer.
• Thread pitch (P): determined by the metric thread standard (usually ISO 261, ISO 262). Both coarse and fine thread pitches are provided for.
• Bolt length (l): determined by the user depending on the connection requirements and is selected from the preferred range of lengths.
• Thread length (b): depends on the thread diameter and the overall length of the bolt and is calculated using the formula specified in the standard.
• “Across flats” dimension (s): the size of the hexagon head used to tighten the bolt. Depends on the thread diameter.
• Head height (k): the height of the head.
• Materials: carbon steel, alloy steel, stainless steel (A2, A4), brass, aluminum, and others.
• Strength classes: depending on the material and purpose, DIN 931 bolts are produced with various strength classes, for example:
  • Carbon steel: 5.6, 8.8, 10.9, 12.9
  • Stainless steel: A2-70, A4-70, A2-80, A4-80
• Tolerances: comply with ISO 4759-1.
• Thread: metric (ISO 261, ISO 262).
• Coatings: may have various protective coatings to increase corrosion resistance (e.g., zinc, nickel, chrome).

Main Requirements:

• Construction and dimensions: the bolt must comply with all requirements for dimensions and shape specified in the DIN 931 standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Mechanical properties: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.
• Marking: must contain information about the strength class and the manufacturer’s trademark.

GOST 15589-70 is an interstate standard titled “Hexagon Head Bolts, Accuracy Class C. Construction and Dimensions.” It establishes the construction and main dimensions of hexagon head bolts of accuracy class C with a nominal thread diameter from 5 to 48 mm. Bolts of this accuracy class are used in connections where high accuracy requirements are not imposed, for example, in building structures, agricultural machinery, etc.

Main Provisions:

Application Area:

• Building structures: joining elements where high accuracy is not required (e.g., temporary structures, auxiliary elements).
• Agricultural machinery: fastening parts that are not subject to high loads.
• General industrial application: general-purpose connections where economy is a priority and accuracy is not critical.
• Auxiliary structures: fastening fences, shields, and other similar elements.

Main Technical Characteristics:

• Bolt type: hexagon head bolt.
• Accuracy class: C (reduced). This means wider dimensional tolerances compared to accuracy classes A (GOST 7805-70) and B (GOST 7798-70).
• Thread diameter (d): from 5 mm to 48 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). As a rule, a coarse thread pitch is used.
• Bolt length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• “Across flats” dimension (S): the size of the hexagon head for tightening the bolt. Depends on the thread diameter.
• Head height (k): the height of the bolt head, depending on the thread diameter.
• Materials: carbon steels.
• Strength classes: as a rule, low strength classes: 3.6; 4.6; 4.8.
• Thread type: metric thread (according to GOST 9150-2002).

Main Requirements:

• Construction: the shape of the head, shank, and thread must comply with the drawings and tables presented in the standard.
• Dimensions: must comply with the established tolerances, which are wider than for bolts of accuracy class A and B.
• Materials: must provide the required mechanical properties.
• Thread: the thread must be clean, without burrs, and defects.
• Coatings: for corrosion protection, bolts can have a zinc coating (the most common option).
• Marking: may be absent or simplified.

GOST 10602-94 is an interstate standard titled “Hexagon Head Bolts with Reduced Wrenching Height for Metal Structures. Construction and Dimensions.” It establishes the construction and dimensions of hexagon head bolts intended for use in metal structures where a reduced wrenching height is required to facilitate installation and reduce the overall dimensions of the connection.

Main Provisions:

Application Area:

• Metal structures: used in joining elements of metal structures where access to the bolt head is limited or it is necessary to reduce the dimensions of the connection. Often used in the construction of bridges, buildings, and other structures.
• Construction: connecting metal structures, fences, facade elements, etc.
• Mechanical engineering (limited): less commonly used in mechanical engineering, usually in cases where it is necessary to reduce the dimensions of the connection in a limited space.

Main Technical Characteristics:

• Bolt type: hexagon head bolt.
• Wrenching height: reduced compared to standard bolts of the same thread diameter. This is the main difference from GOST 7798-70 and GOST 7805-70.
• Thread diameter (d): from 16 mm to 48 mm.
• Thread pitch (P): determined according to GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (usually coarse).
• Bolt length (l): determined from a series of preferred lengths specified in the standard, depending on the thread diameter and the thickness of the elements being joined.
• “Across flats” dimension (S): determined by the standard, and it is smaller than the “across flats” dimension for bolts according to GOST 7798 and GOST 7805 with the same thread diameter. For example, for an M20 bolt according to GOST 7798, the “across flats” dimension is 30 mm, while according to GOST 10602 it is only 27 mm.
• Head height (k): determined by the standard.
• Materials: carbon and alloy steels. The steel grade must correspond to the required strength class.
• Strength classes: 5.8, 8.8, 10.9. The choice of strength class depends on the design loads in the connection.
• Thread type: metric thread (according to GOST 9150-2002).
• Accuracy class: B (according to the instructions in the standard).

Main Requirements:

• Construction: the shape of the head, shank, and thread, as well as all dimensions (including the reduced “across flats” dimension) must strictly comply with the drawings and tables given in the standard.
• Material: the bolt material must correspond to the selected strength class and provide the specified mechanical properties (tensile strength, yield strength, elongation).
• Thread: the thread must be clean, without burrs, dents, or other defects. Must comply with the requirements of thread standards (GOST 9150, GOST 24705).
• Hardness: must meet the requirements of the strength class.
• Coatings: bolts may have protective coatings (e.g., zinc) to increase corrosion resistance.
• Marking: the bolt head must have clear marking containing information about the strength class and the manufacturer’s trademark.

GOST 7805-70 is an interstate standard titled “Hexagon Head Bolts, Accuracy Class A. Construction and Dimensions.” It defines the construction and main dimensions of hexagon head bolts of accuracy class A with a nominal thread diameter from 1.6 to 48 mm. These bolts are used in connections requiring increased accuracy and reliability in mechanical engineering, instrument engineering, and other industries.

Main Provisions:

Application Area:

• Mechanical engineering: connections requiring high accuracy and reliability (e.g., gearboxes, engines).
• Instrument engineering: fastening elements of instruments, where precise fixation and connection stability are important.
• Aviation industry: in connections subject to high loads and vibrations.
• Other industries: in critical structures and connections where guaranteed fastener quality is required.

Main Technical Characteristics:

• Bolt type: hexagon head bolt.
• Accuracy class: A (high). This class has stricter requirements for tolerances and manufacturing quality compared to accuracy class B (GOST 7798-70).
• Thread diameter (d): from 1.6 mm to 48 mm. A wide range of sizes.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). Typically, a coarse thread pitch.
• Bolt length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• “Across flats” dimension (S): the size of the hexagon head used to tighten the bolt. Depends on the thread diameter.
• Head height (k): the height of the bolt head, depending on the thread diameter.
• Materials: steels of various grades (carbon, alloy), the choice of which depends on the requirements for the strength of the connection and operating conditions.
• Strength classes: 5.8, 8.8, 10.9, 12.9 and others (depending on the connection requirements).
• Thread type: metric thread (according to GOST 9150-2002).

Main Requirements:

• Construction: the shape and dimensions of the head, shank, and thread must strictly comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances, which are stricter than for class B accuracy bolts.
• Materials: the bolt material must comply with the selected strength class and provide the necessary mechanical properties. Certificates of conformity must be provided.
• Thread: the thread must be clean, without burrs, dents, or other defects, and comply with the requirements of GOST 9150.
• Hardness: must meet the requirements of the strength class.
• Coatings: for corrosion protection, bolts can have various coatings (zinc, cadmium, oxide, phosphate, etc.). The type of coating must correspond to the operating conditions.
• Marking: the bolt head must have clear and indelible marking containing information about the strength class and the manufacturer’s trademark.

GOST 7795-70 is an interstate standard titled “Eye Bolts. Construction and Dimensions.” It establishes the construction and main dimensions of eye bolts with a nominal thread diameter from 6 to 24 mm. Eye bolts are designed for quick-release connections where frequent unscrewing and screwing is required without the use of tools, or in hard-to-reach places.

Main Provisions:

Application Area:

• Mechanical engineering: quick-release connections of covers, hatches, guards, and other parts requiring frequent access.
• Instrument engineering: securing panels, housings, and other instrument elements.
• Production of tooling: for fastening interchangeable tooling elements.
• In everyday life: fastening folding structures, furniture elements, etc.

Main Technical Characteristics:

• Bolt type: eye bolt.
• Thread diameter (d): from 6 mm to 24 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (usually coarse pitch).
• Bolt length (l): depends on the thread diameter and is determined from a series of preferred lengths specified in the standard.
• Head dimensions: the geometric dimensions of the head (length, width, thickness) are standardized and depend on the thread diameter.
• Eyelet dimensions: the dimensions of the eyelet (hole in the head) are also standardized and are designed for ease of gripping and flipping the bolt.
• Materials: carbon steels, less often - alloy steels. The choice of material depends on the required strength and operating conditions.
• Strength classes: strength classes are usually not standardized, as the main task is to ensure the convenience of a quick connection, and not high strength.
• Thread type: metric (according to GOST 9150-2002).

Main Requirements:

• Construction: the construction of the bolt must comply with the drawings and requirements of the standard. Special attention is paid to the shape of the head and eyelet, providing ease of use.
• Dimensions: all dimensions must comply with the tolerances established in the standard.
• Materials: the bolt material must provide the required mechanical properties and corrosion resistance under operating conditions.
• Thread: the thread must be clean, without burrs, and defects.
• Hinge connection: the bolt head must rotate freely relative to the shank (threaded part).
• Coatings: bolts can have various coatings (zinc, cadmium, etc.) for corrosion protection. The requirements for coatings are determined by the corresponding standards.
• Marking: must contain information about the thread diameter and the manufacturer’s trademark.

GOST 7798-70 is an interstate standard titled “Hexagon Head Bolts, Accuracy Class B. Construction and Dimensions.” It establishes the construction and main dimensions of hexagon head bolts of accuracy class B with a nominal thread diameter from 6 to 48 mm. Bolts conforming to this standard are widely used in various general-purpose connections in mechanical engineering, construction, and other industries.

Main Provisions:

Application Area:

• Mechanical engineering: joining parts and assemblies of machines and mechanisms.
• Construction: joining elements of metal structures (trusses, beams, columns, etc.).
• Instrument engineering: fastening parts in instruments and equipment.
• Furniture manufacturing: assembly of furniture.
• In other industries: for a wide range of general-purpose connections.

Main Technical Characteristics:

• Bolt type: hexagon head bolt.
• Accuracy class: B (medium). Defines tolerances on dimensions and shape.
• Thread diameter (d): from 6 mm to 48 mm. The standard covers a range of the most common sizes.
• Thread pitch (P): determined by the thread standard (usually GOST 24705, metric thread). Both coarse and fine thread pitches are provided for.
• Bolt length (l): determined from a series of preferred lengths, depending on the thread diameter.
• “Across flats” dimension (S): the size of the hexagon head used to tighten the bolt. Determined by the standard depending on the thread diameter.
• Head height (k): the height of the head, also determined by the standard.
• Materials: various grades of steel (carbon and alloy), the choice of which depends on the required strength class of the bolt.
• Strength classes: 4.6, 4.8, 5.6, 5.8, 8.8. Define the minimum values of tensile strength and yield strength of the bolt material.
• Thread type: metric thread (according to GOST 9150).
• Thread tolerance field: 6g (for bolts without coating) and 6h (for bolts with coating).

Main Requirements:

• Construction and dimensions: the shape of the head, shank, and thread, as well as all dimensions, must strictly comply with the requirements specified in the drawings and tables of the standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties (tensile strength, yield strength, elongation). Material quality certificates must be provided.
• Thread: the thread must be clean, without burrs, dents, or other defects. Must comply with the requirements of the thread standard (GOST 9150, GOST 24705).
• Hardness: must meet the requirements of the strength class.
• Coatings (if provided): coatings (zinc, cadmium, oxide, phosphate, etc.) must be uniform, without defects, and comply with the requirements of coating standards. Coatings provide corrosion protection.
• Marking: the bolt head must have clear marking indicating the strength class and, as a rule, the trademark of the manufacturer.

DIN 7985 is a German standard “Cylindrical Head Screws with Cross Recess.” It defines the construction, dimensions, and requirements for cylindrical head screws that have a cross recess (Phillips or Pozidriv), with a nominal thread diameter from 1.6 to 10 mm. These screws are widely used in various industries and in everyday life for creating connections where ease of installation with a Phillips or Pozidriv screwdriver and a relatively small protruding head are required.

Main Provisions:

Application Area:

• Furniture manufacturing: assembly of furniture.
• Instrument engineering: fastening panels, housings, and other elements of instruments.
• Radio-electronic industry: fastening components.
• Household appliance manufacturing: assembly of household appliances.
• General industrial application: a wide range of connections where ease of installation and reliable fixation are required.

Main Technical Characteristics:

• Screw type: cylindrical head screw.
• Head shape: cylindrical (with straight side walls and a flat top surface).
• Slot type: cross recess (Phillips - PH or Pozidriv - PZ).
• Thread diameter (d): Usually from M1.6 to M10.
• Thread pitch (P): determined by the metric thread standard (usually ISO 261, ISO 262). Usually coarse thread pitch.
• Screw length (l): determined by the user depending on the connection requirements and is selected from the preferred range of lengths.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): determined by the standard depending on the thread diameter.
• Materials: carbon steel, stainless steel (A2, A4), brass, aluminum, and others.
• Strength classes: depending on the material and purpose, DIN 7985 screws can be manufactured with various strength classes, for example:
  • Carbon steel: 4.8
  • Stainless steel: A2-70, A4-70
• Tolerances: comply with ISO 4759-1.
• Thread: metric (ISO 261, ISO 262).
• Coatings: may have various protective coatings to increase corrosion resistance (e.g., zinc, nickel, chrome).

Main Requirements:

• Construction and dimensions: the screw must comply with all requirements for dimensions and shape specified in the DIN 7985 standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Slot: the cross recess must be formed correctly to ensure reliable engagement with the screwdriver.
• Mechanical properties: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.

DIN 966 is a German standard “Round Head Screws with Cross Recess.” It defines the construction, dimensions, and requirements for round head screws that have a cross recess (Phillips or Pozidriv), with a nominal thread diameter from 1.6 to 10 mm. These screws are widely used in various industries and in everyday life where an aesthetic connection and ease of installation with a Phillips or Pozidriv screwdriver are required.

Main Provisions:

Application Area:

• Furniture manufacturing: assembly of furniture.
• Instrument engineering: fastening panels, housings, and other elements of instruments.
• Radio-electronic industry: fastening components.
• Everyday application: a wide range of applications in everyday life where an aesthetic connection is required.
• Household appliance manufacturing: assembly of household appliances.

Main Technical Characteristics:

• Screw type: round head screw.
• Head shape: round (spherical).
• Slot type: cross recess (Phillips - PH or Pozidriv - PZ).
• Thread diameter (d): usually from M1.6 to M10.
• Thread pitch (P): determined by the metric thread standard (usually ISO 261, ISO 262). Usually coarse thread pitch.
• Screw length (l): determined by the user depending on the connection requirements and is selected from the preferred range of lengths.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): determined by the standard depending on the thread diameter.
• Materials: Carbon steel, stainless steel (A2, A4), brass, aluminum, and others.
• Strength classes: Depending on the material and purpose, DIN 966 screws can be manufactured with various strength classes, for example:
  • Carbon steel: 4.8
  • Stainless steel: A2-70, A4-70
• Tolerances: comply with ISO 4759-1.
• Thread: metric (ISO 261, ISO 262).
• Coatings: may have various protective coatings to increase corrosion resistance (e.g., zinc, nickel, chrome).

Main Requirements:

• Construction and dimensions: the screw must comply with all requirements for dimensions and shape specified in the DIN 966 standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Slot: the cross recess must be formed correctly to ensure reliable engagement with the screwdriver.
• Mechanical properties: must meet the requirements of the strength class.
• Coatings (if provided): Coatings must be uniform, without defects, and comply with the requirements of coating standards.

DIN 965 is a German standard “Countersunk Head Screws with Cross Recess.” It defines the construction, dimensions, and requirements for countersunk head screws that have a cross recess (Phillips or Pozidriv), with a nominal thread diameter from 1.6 to 10 mm. These screws are widely used in various industries and in everyday life where a flush connection and ease of installation with a Phillips or Pozidriv screwdriver are required.

Main Provisions:

Application Area:

• Furniture manufacturing: assembly of furniture.
• Instrument engineering: fastening panels, housings, and other elements of instruments.
• Radio-electronic industry: fastening components.
• Woodworking: fastening fittings to wooden products.
• Everyday application: a wide range of applications in everyday life where a flush connection is required.

Main Technical Characteristics:

• Screw type: countersunk head screw.
• Head shape: countersunk (conical).
• Slot type: cross recess (Phillips - PH or Pozidriv - PZ).
• Thread diameter (d): usually from M1.6 to M10.
• Thread pitch (P): determined by the metric thread standard (usually ISO 261, ISO 262). Usually coarse thread pitch.
• Screw length (l): determined by the user depending on the connection requirements and is selected from the preferred range of lengths.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): determined by the standard depending on the thread diameter.
• Head cone angle: 90 degrees.
• Materials: carbon steel, stainless steel (A2, A4), brass, aluminum, and others.
• Strength classes: Depending on the material and purpose, DIN 965 screws can be manufactured with various strength classes, for example:
  • Carbon steel: 4.8
  • Stainless steel: A2-70, A4-70
• Tolerances: comply with ISO 4759-1.
• Thread: metric (ISO 261, ISO 262).
• Coatings: may have various protective coatings to increase corrosion resistance (e.g., zinc, nickel, chrome).

Main Requirements:

• Construction and dimensions: the screw must comply with all requirements for dimensions and shape specified in the DIN 965 standard. It is important that the head cone angle and diameter are correct to ensure a flush fit.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Slot: the cross recess must be formed correctly to ensure reliable engagement with the screwdriver.
• Mechanical properties: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.

DIN 912 is a German standard “Cylindrical Head Screws with Hexagon Socket.” It defines the construction, dimensions, and requirements for cylindrical head screws with an internal hexagon (socket), with a nominal thread diameter from 1.6 to 36 mm. These screws are widely used in mechanical engineering, instrument engineering, and other industries for creating reliable and strong connections, especially in places with limited access to the screw head.

Main Provisions:

Application Area:

• Mechanical engineering: joining parts and assemblies of machines and mechanisms where high strength and reliability are required.
• Instrument engineering: fastening elements in instruments and equipment.
• Automotive industry: assembly of automobiles.
• Equipment manufacturing: fastening parts of machine tools, molds, and other industrial equipment.
• Other industries: for a wide range of connections where reliable fixation and the ability to apply a high torque are required.

Main Technical Characteristics:

• Screw type: cylindrical head screw.
• Head shape: cylindrical.
• Slot type: internal hexagon (socket).
• Thread diameter (d): usually from M1.6 to M36.
• Thread pitch (P): determined by the metric thread standard (usually ISO 261, ISO 262). Both coarse and fine thread pitches are provided for.
• Screw length (l): determined by the user depending on the connection requirements and is selected from the preferred range of lengths.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): determined by the standard depending on the thread diameter.
• “Across flats” dimension (s): the size of the internal hexagon used to tighten the screw. Depends on the thread diameter.
• Materials: carbon steel, alloy steel, stainless steel (A2, A4), brass, aluminum, and others.
• Strength classes: depending on the material and purpose, DIN 912 screws are produced with various strength classes, for example:
  • Carbon steel: 8.8, 10.9, 12.9
  • Stainless steel: A2-70, A4-70, A2-80, A4-80
• Tolerances: comply with ISO 4759-1.
• Thread: metric (ISO 261, ISO 262).
• Coatings: may have various protective coatings to increase corrosion resistance (e.g., zinc, nickel, chrome).

Main Requirements:

• Construction and dimensions: the screw must comply with all requirements for dimensions and shape specified in the DIN 912 standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Mechanical properties: must meet the requirements of the strength class.
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.

GOST 1476-93 is an interstate standard titled “Cylindrical Head Screws with Hexagon Socket.” It defines the construction and dimensions of cylindrical head screws with an internal hexagon (socket), with a nominal thread diameter from 3 to 24 mm. These screws are used in connections where reliable fixation and the ability to apply a high torque during tightening are required, as well as in cases where access to the screw head is limited.

Main Provisions:

Application Area:

• Mechanical engineering: connections requiring high strength and reliability, as well as in places with limited access to the screw head.
• Instrument engineering: fastening elements in instruments and equipment.
• Machine tool engineering: fastening elements of machine tools.
• Automotive industry: assembly of automobiles.
• In various industries: for a wide range of connections where reliable fixation and the ability to apply a high torque are required.

Main Technical Characteristics:

• Screw type: cylindrical head screw.
• Head shape: cylindrical.
• Slot type: internal hexagon (socket).
• Thread diameter (d): from 3 mm to 24 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). Usually coarse pitch.
• Screw length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): the height of the screw head, depending on the thread diameter.
• “Across flats” dimension (s): the size of the internal hexagon used to tighten the screw. Depends on the thread diameter.
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 8.8, 10.9, 12.9 (for steel screws).
• Thread type: metric thread (according to GOST 9150-2002).
• Accuracy class: A (usually).

Main Requirements:

• Construction: the shape of the head, shank, and internal hexagon must comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Slot: the internal hexagon must be formed correctly, providing reliable engagement with the tool.
• Hardness: must meet the requirements of the strength class.
• Coatings: for corrosion protection, screws can have various coatings (zinc, oxide, phosphate, etc.).
• Marking: must contain information about the thread diameter, screw length, strength class, and the manufacturer’s trademark.

GOST 11738-84 is an interstate standard titled “Set Screws with Hexagon Socket. Accuracy Classes A and B.” It defines the construction and main dimensions of set screws with an internal hexagon (socket) and various end shapes (pointed, flat, stepped, cylindrical, etc.) with a nominal thread diameter from 1.6 to 24 mm. Set screws are designed to fix parts relative to each other by means of the end of the screw pressing against the surface of the part.

Main Provisions:

Application Area:

• Mechanical engineering: fixing shafts, gears, pulleys, and other parts on shafts.
• Instrument engineering: fastening elements in instruments and equipment.
• Machine tool engineering: fixing tools and fixtures on machines.
• In various industries: for a wide range of applications where reliable fixation of parts relative to each other is required.

Main Technical Characteristics:

• Screw type: set screw.
• Head shape: absent (headless screw, completely screwed into the hole).
• Slot shape: internal hexagon (socket).
• End shape: various options (pointed, flat, stepped, cylindrical, conical, etc.) - selected depending on the application.
• Thread diameter (d): from 1.6 mm to 24 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). Usually coarse pitch.
• Screw length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• “Across flats” dimension (s): the size of the internal hexagon used to tighten the screw. Depends on the thread diameter.
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: depending on the material - 14H, 22H, 33H, 45H (for steel).
• Thread type: metric thread (according to GOST 9150-2002).
• Accuracy class: A and B (indicated in the screw designation).

Main Requirements:

• Construction: the shape of the screw (including the end shape), shank, and socket must comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances for accuracy class A or B.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Slot: the internal hexagon must be formed correctly, providing reliable engagement with the tool.
• Hardness: must meet the requirements of the strength class.
• Coatings: for corrosion protection, screws can have various coatings (zinc, oxide, etc.).
• Marking: must contain information about the thread diameter, screw length, strength class, end shape (symbol), and the manufacturer’s trademark.

GOST 17475-80 is an interstate standard titled “Cylindrical Head Screws. Construction and Dimensions.” It defines the construction and main dimensions of cylindrical head screws with a nominal thread diameter from 1 to 20 mm. Cylindrical head screws are used in various connections where reliable fixation and ease of installation/removal are required.

Main Provisions:

Application Area:

• Mechanical engineering: assembly of various machines and mechanisms.
• Instrument engineering: fastening elements of instruments, housings, and panels.
• Radio-electronic industry: fastening components.
• Furniture manufacturing: assembly of furniture.
• In various industries: for a wide range of connections.

Main Technical Characteristics:

• Screw type: cylindrical head screw.
• Head shape: cylindrical. The head has a cylindrical shape with a flat top surface.
• Thread diameter (d): from 1 mm to 20 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). A coarse pitch is usually used.
• Screw length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): the height of the screw head, depending on the thread diameter.
• Slot type: straight slot, Phillips slot (types H and Z), internal hexagon (rare).
• Materials: carbon steels, stainless steels, brass, aluminum alloys.
• Strength classes: for carbon steels - 3.6, 4.6, 4.8, 5.8. For stainless steels - A2-50, A4-50 (approximate values).
• Thread type: metric thread (according to GOST 9150-2002).
• Accuracy class: B (usually).

Main Requirements:

• Construction: the shape of the head, shank, and slot must comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Slot: the slot must be formed correctly, providing reliable engagement with the tool.
• Coatings: for corrosion protection, screws can have various coatings (zinc, nickel, chrome, etc.).
• Marking: must contain information about the thread diameter, screw length, strength class (for steel screws), and the manufacturer’s trademark.

GOST 17474-80 is an interstate standard titled “Countersunk Head Screws. Construction and Dimensions.” It defines the construction and main dimensions of countersunk head screws with a nominal thread diameter from 1 to 20 mm. Countersunk head screws are used in connections where the screw head should be flush with the surface of the connected parts.

Main Provisions:

Application Area:

• Mechanical engineering: assembly of instruments, mechanisms, and equipment where a smooth surface and the absence of protruding fasteners are required.
• Instrument engineering: fastening panels, housings, and other elements of instruments.
• Furniture manufacturing: Furniture assembly.
• Woodworking: fastening fittings to wooden products.
• In everyday life: various connections where a flush fit is required.

Main Technical Characteristics:

• Screw type: countersunk head screw.
• Head shape: countersunk. The head has a conical shape that allows it to be completely recessed into the hole.
• Thread diameter (d): from 1 mm to 20 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). A coarse pitch is usually used.
• Screw length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): the height of the screw head (in fact, this is the thickness of the head at the edge), depending on the thread diameter.
• Head cone angle: usually 90 degrees.
• Slot type: straight slot, Phillips slot (types H and Z), internal hexagon (rare).
• Materials: carbon steels, stainless steels, brass, aluminum alloys.
• Strength classes: for carbon steels - 3.6, 4.6, 4.8, 5.8. For stainless steels - A2-50, A4-50 (approximate values).
• Thread type: metric thread (according to GOST 9150-2002).
• Accuracy class: B (usually).

Main Requirements:

• Construction: the shape of the head, shank, and slot must comply with the drawings and tables presented in the standard. It is important that the cone angle meets the requirements to ensure a flush fit.
• Dimensions: all dimensions must comply with the established tolerances.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Slot: the slot must be formed correctly, providing reliable engagement with the tool.
• Coatings: for corrosion protection, screws can have various coatings (zinc, nickel, chrome, etc.).
• Marking: must contain information about the thread diameter, screw length, strength class (for steel screws), and the manufacturer’s trademark.

GOST 17473-80 is an interstate standard titled “Round Head Screws. Construction and Dimensions.” It defines the construction and main dimensions of round head screws with a nominal thread diameter from 1 to 20 mm. Round head screws are widely used in various connections where an aesthetic appearance is required and the presence of protruding fasteners is undesirable.

Main Provisions:

Application Area:

• Mechanical engineering: assembly of various machines and mechanisms, especially in places where appearance is important.
• Instrument engineering: fastening elements of instruments, housings, and panels.
• Furniture manufacturing: assembly of furniture.
• Radio-electronic industry: fastening components.
• In everyday life: for various connections where aesthetic fasteners are required.

Main Technical Characteristics:

• Screw type: round head screw.
• Thread diameter (d): from 1 mm to 20 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). As a rule, a coarse thread pitch is used.
• Screw length (l): depends on the thread diameter and is selected from a series of preferred lengths established by the standard.
• Head diameter (D): determined by the standard depending on the thread diameter.
• Head height (k): the height of the screw head, depending on the thread diameter.
• Slot type: straight slot (most common), Phillips slot (types H and Z), internal hexagon (rare).
• Materials: carbon steels, stainless steels, brass, aluminum alloys.
• Strength classes: for carbon steels - 3.6, 4.6, 4.8, 5.8. For stainless steels - A2-50, A4-50 (approximate values).
• Thread type: metric thread (according to GOST 9150-2002).
• Accuracy class: B (usually).

Main Requirements:

• Construction: the shape of the head, shank, and slot must comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Slot: the slot must be formed correctly, providing reliable engagement with the tool.
• Coatings: for corrosion protection, screws can have various coatings (zinc, nickel, chrome, etc.).
• Marking: must contain information about the thread diameter, screw length, strength class (for steel screws), and the manufacturer’s trademark.

DIN 985 is a German standard “Hexagon Self-Locking Nuts with Non-Metallic Insert.” It defines the construction, dimensions, and requirements for hexagon nuts that have a nylon or other non-metallic insert, which provides a self-locking effect and prevents the nut from loosening due to vibration and other dynamic loads. The thread diameter range is typically from M3 to M39.

Main Provisions:

Application Area:

• Mechanical engineering: connections subject to vibration (e.g., in engines, pumps, compressors).
• Automotive industry: assembly of automobiles.
• Aviation industry: in connections where high reliability and prevention of self-loosening are required.
• Railway transport: fastening parts of rolling stock.
• Household appliances: assembly of devices subject to vibration.
• Virtually all industries where it is necessary to prevent self-loosening of threaded connections.

Main Technical Characteristics:

• Nut type: hexagon self-locking nut.
• Thread type: metric thread (according to ISO 261 and ISO 262, usually coarse pitch).
• Thread diameter (d): usually from M3 to M39.
• Thread pitch (P): determined in accordance with ISO 261 or ISO 262 (usually coarse pitch).
• “Across flats” dimension (s): determined by the standard depending on the thread diameter.
• Nut height (m): determined by the standard depending on the thread diameter, including the insert height.
• Materials:
  • Carbon steel (with various strength classes).
  • Stainless steel (A2, A4).
  • Brass (less common).
• Strength classes:
  • Steel: 5, 8, 10 (and others, depending on the material and requirements).
  • Stainless steel: A2-70, A4-70.
• Insert material:
  • Nylon (PA6, PA66).
  • Other polymers that provide a self-locking effect.
• Tolerances: comply with ISO 4759-1.
• Coatings: may have various protective coatings to increase corrosion resistance, such as:
  • Zinc (galvanic or hot-dip galvanizing).
  • Nickel.
  • Oxide (blackening).

Main Requirements:

• Construction and dimensions: the nut must comply with all requirements for dimensions and shape specified in the DIN 985 standard. Special attention is paid to the correct installation and retention of the non-metallic insert.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties. The insert material must provide the necessary self-locking effect.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Mechanical properties: must meet the requirements of the strength class (hardness, tensile strength, yield strength, etc.).
• Self-locking properties: the nut must provide the specified torque resistance to loosening after a certain number of tightening-loosening cycles.
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.

DIN 934 is a German standard “Hexagon Nuts.” It defines the construction, dimensions, material requirements, and strength classes for hexagon nuts with metric threads from M1 to M160. DIN 934 is one of the most common standards for nuts, used in various industries and in everyday life to create reliable threaded connections.

Main Provisions:

Application Area:

• Mechanical engineering: joining parts and assemblies of machines and mechanisms.
• Construction: fastening elements of structures.
• Instrument engineering: fastening elements in instruments and equipment.
• Automotive industry: assembly of automobiles.
• Equipment manufacturing: fastening parts of machine tools, molds, and other industrial equipment.
• In everyday life: for various connections.
• Virtually all industries where threaded connections are used.

Main Technical Characteristics:

• Nut type: hexagon nut.
• Thread type: metric thread (according to ISO 261 and ISO 262, including both coarse and fine pitch).
• Thread diameter (d): from M1 to M160.
• Thread pitch (P): determined in accordance with ISO 261 or ISO 262 (coarse or fine pitch).
• “Across flats” dimension (s): determined by the standard depending on the thread diameter.
• Nut height (m): determined by the standard depending on the thread diameter.
• Materials:
  • Carbon steel (with various strength classes).
  • Alloy steel (with various strength classes).
  • Stainless steel (A2, A4).
  • Brass.
  • Aluminum.
• Strength classes:
  • Steel: 5, 6, 8, 10, 12 (and others, depending on the material and requirements).
  • Stainless steel: A2-70, A4-70, A2-80, A4-80.
• Tolerances: comply with ISO 4759-1.
• Coatings: may have various protective coatings to increase corrosion resistance, such as:
  • Zinc (galvanic or hot-dip galvanizing).
  • Nickel.
  • Chrome.
  • Oxide (blackening).

Main Requirements:

• Construction and dimensions: the nut must comply with all requirements for dimensions and shape specified in the DIN 934 standard.
• Material: must meet the requirements for the selected strength class and provide the specified mechanical properties.
• Thread: the thread must be clean, without defects, and comply with the requirements of metric thread standards.
• Mechanical properties: must meet the requirements of the strength class (hardness, tensile strength, yield strength, etc.).
• Coatings (if provided): coatings must be uniform, without defects, and comply with the requirements of coating standards.

GOST 9064-75 is an interstate standard titled “Nuts for Flanged Joints with Medium Temperatures from 0 to 650 °C. Types and Main Dimensions.” It establishes the types and main dimensions of nuts intended for connecting flanges of pipelines, fittings, machine parts, and apparatus operating under high-temperature conditions (from 0 to 650 °C). These nuts must provide a reliable and leak-proof flanged connection under high-temperature and pressure conditions.

Main Provisions:

Application Area:

• Energy industry: connecting flanges of steam and hot water pipelines, fittings, and equipment of thermal and nuclear power plants.
• Oil and gas industry: connecting pipelines and equipment operating with heated products.
• Chemical industry: connecting pipelines and equipment operating with heated corrosive media.
• Other industries: for connections operating under high-temperature conditions.

Main Technical Characteristics:

• Fastener type: hexagon nut.
• Application area: flanged joints operating at high temperatures (from 0 to 650 °C).
• Thread type: metric thread (according to GOST 24705-2004 and GOST 9150-2002).
• Thread diameter (d): from 6 mm to 48 mm.
• Thread pitch (P): determined for the corresponding thread diameter according to GOST 24705-2004 (coarse or fine).
• “Across flats” dimension (S): the size of the nut’s hexagon for tightening. Depends on the thread diameter.
• Nut height (m): the height of the nut, depending on the thread diameter. The height may vary depending on the nut type.
• Materials: special heat-resistant steels that ensure the preservation of strength and leak-tightness of the connection at high temperatures. Steel grades are determined depending on the specific operating conditions.
• Strength classes: depend on the material and operating conditions.
• Nut types (main):
  • Type 1: standard height hexagon nuts.
  • Type 2: increased height hexagon nuts.
  • Type 3: cap nuts.
• Design features: the nut design may include special elements to prevent self-loosening under high-temperature and vibration conditions.

Main Requirements:

1. Construction: the shape of the nut and the dimensions of the hexagon must comply with the drawings and tables presented in the standard.
2. Dimensions: all dimensions must comply with the established tolerances.
3. Materials: must provide the required mechanical properties and resistance to oxidation and deformation at high temperatures. The nut material must be compatible with the stud (bolt) material to prevent corrosion at high temperatures.
4. Thread: the thread must be clean, without burrs, and defects, and comply with the requirements of metric thread standards.
5. Hardness: must meet the requirements of the strength class.
6. Coatings: generally not used, as most coatings cannot withstand high temperatures. The correct choice of material is more important.
7. Marking: must contain information about the steel grade and the manufacturer’s trademark.

GOST 10605-94 is an interstate standard titled “Extra High (High) Hexagon Nuts, Accuracy Class B. Construction and Dimensions.” It establishes the construction and main dimensions of extra-high (high) hexagon nuts of accuracy class B with a nominal thread diameter from 6 to 48 mm. These nuts are used in connections where increased thread load-bearing capacity is required or it is necessary to increase the thread engagement length with a bolt (stud).

Main Provisions:

Application Area:

• Mechanical engineering: connections subject to high loads (e.g., in heavy machinery).
• Construction: in connections requiring increased reliability and safety margin.
• Mining industry: in equipment operating in harsh conditions.
• Transport engineering: in connections experiencing vibration loads.
• Other industries: in connections where it is necessary to increase the thread load-bearing capacity or the thread engagement length.

Main Technical Characteristics:

• Nut type: hexagon nut.
• Accuracy class: B (normal).
• Design: extra high (high). The main difference from GOST 5915-70 is the increased nut height.
• Thread diameter (d): from 6 mm to 48 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). Usually coarse pitch.
• “Across flats” dimension (S): the size of the nut’s hexagon used to tighten the nut. Depends on the thread diameter.
• Nut height (m): increased compared to standard hexagon nuts (GOST 5915-70) of the same thread diameter. This is the main parameter that defines the nut type.
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5, 6, 8, 10, 12 (for steel nuts).
• Thread type: metric thread (according to GOST 9150-2002).

Main Requirements:

• Construction: the shape of the nut and the dimensions of the hexagon must comply with the drawings and tables presented in the standard. The nut height is especially important and must be greater than that of standard nuts.
• Dimensions: all dimensions must comply with the established tolerances for accuracy class B.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Hardness: must meet the requirements of the strength class.
• Coatings: for corrosion protection, nuts can have various coatings (zinc, oxide, cadmium, etc.).
• Marking: must contain information about the strength class (for steel nuts) and the manufacturer’s trademark.

GOST 5927-70 is an interstate standard titled “Hexagon Nuts, Accuracy Class A. Construction and Dimensions.” It establishes the construction and main dimensions of hexagon nuts of accuracy class A with a nominal thread diameter from 1.6 to 48 mm. These nuts are used in conjunction with bolts, screws, and studs in connections where high accuracy and reliable fixation are required.

Main Provisions:

Application Area:

• Mechanical engineering: connections requiring high accuracy and reliability (e.g., gearboxes, engines).
• Instrument engineering: fastening elements of instruments where precise fixation and stable connection are important.
• Aviation industry: in connections subject to high loads and vibrations.
• Other industries: in critical structures and connections where guaranteed fastener quality is necessary.

Main Technical Characteristics:

• Nut type: hexagon nut.
• Accuracy class: A (high). This class has stricter requirements for tolerances and manufacturing quality compared to accuracy class B (GOST 5915-70).
• Thread diameter (d): from 1.6 mm to 48 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). Usually coarse pitch.
• “Across flats” dimension (S): the size of the nut’s hexagon used to tighten the nut. Depends on the thread diameter.
• Nut height (m): the height of the nut, depending on the thread diameter.
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5, 6, 8, 10, 12 (for steel nuts).
• Thread type: metric thread (according to GOST 9150-2002).

Main Requirements:

• Construction: the shape of the nut and the dimensions of the hexagon must comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances, which are stricter than for nuts of accuracy class B.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Hardness: must meet the requirements of the strength class.
• Coatings: for corrosion protection, nuts can have various coatings (zinc, oxide, cadmium, etc.).
• Marking: must contain information about the strength class (for steel nuts) and the manufacturer’s trademark.

GOST 5915-70 is an interstate standard titled “Hexagon Nuts, Accuracy Class B. Construction and Dimensions.” It establishes the construction and main dimensions of hexagon nuts of accuracy class B with a nominal thread diameter from 1.6 to 48 mm. These nuts are used in conjunction with bolts, screws, and studs in connections where standard accuracy and reliable fixation are required.

Main Provisions:

Application Area:

• Mechanical engineering: joining parts and assemblies of machines and mechanisms.
• Construction: fastening elements of metal and wooden structures.
• Instrument engineering: fastening elements in instruments and equipment.
• Automotive industry: assembly of automobiles.
• In various industries: for a wide range of general-purpose connections.

Main Technical Characteristics:

• Nut type: hexagon nut.
• Accuracy class: B (normal).
• Thread diameter (d): from 1.6 mm to 48 mm.
• Thread pitch (P): determined by GOST 24705-2004 (ISO 724:1993) for the corresponding diameter (metric thread). Usually coarse pitch.
• “Across flats” dimension (S): the size of the nut’s hexagon used to tighten the nut. Depends on the thread diameter.
• Nut height (m): the height of the nut, depending on the thread diameter.
• Materials: carbon steels, alloy steels, stainless steels.
• Strength classes: 5, 6, 8, 10, 12 (for steel nuts).
• Thread type: metric thread (according to GOST 9150-2002).

Main Requirements:

• Construction: the shape of the nut and the dimensions of the hexagon must comply with the drawings and tables presented in the standard.
• Dimensions: all dimensions must comply with the established tolerances for accuracy class B.
• Materials: must provide the required mechanical properties and corrosion resistance.
• Thread: the thread must be clean, without burrs, and defects.
• Hardness: must meet the requirements of the strength class.
• Coatings: for corrosion protection, nuts can have various coatings (zinc, oxide, cadmium, etc.).
• Marking: must contain information about the strength class (for steel nuts) and the manufacturer’s trademark.

GOST 13973-74 is an interstate standard that establishes the construction and dimensions of plugs for pipe connections using an external cone. The standard defines the parameters of the tapered thread, the geometric dimensions of the plugs, and the requirements for the materials and quality of their manufacture, ensuring interchangeability and leak-tightness of the connections.

Main Provisions:

Application Area:

• Mechanical engineering: for sealing channels and holes in hydraulic and pneumatic systems.
• Instrument engineering: in measuring instruments and other devices.
• Plumbing and heating: for sealing connections in water supply, heating, and sewage systems.
• Oil and gas industry: for sealing pipelines and equipment.
• Chemical industry: for working with various liquids and gases.
• General industrial application: in various pipeline systems and equipment.