Dish head

Elliptical and torispherical heads according to DIN standards made from carbon, alloy, corrosion-resistant, and heat-resistant steels for the oil and gas industry. Delivery to the destination point, available in various diameters. A dished head is a component used in pipeline systems and pressure vessels to hermetically close the ends of vessels, tanks, and heat exchangers. It protects the internal contents from the external environment and retains internal pressure without deformation or leakage. In industrial applications, two main types are commonly used: elliptical heads and torispherical heads. Elliptical heads are typically used in vessels operating under constant or variable pressure because their shape distributes loads evenly across the entire surface. Torispherical heads are widely used in systems with limited installation space, where reinforced edges and reduced overall height are required.

Elliptical heads: DIN, EN, and ASME standards

Elliptical heads are manufactured from stainless austenitic steels, heat-resistant alloys, alloy steels, and carbon steels. In Europe, their parameters are defined by DIN and EN standards, which specify the radius of curvature, wall thickness, and edge geometry. In the United States, similar requirements are regulated by the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 (UG-32). The use of ASME and ASTM standards (for example, ASTM A516 for boiler and pressure vessel steels and ASTM A240 for stainless steels) ensures precise geometry, uniform pressure distribution, and reliable welded joints. As a result, elliptical heads manufactured according to ASME/ASTM standards meet the strict requirements of the oil and gas, chemical, and power generation industries.

Torispherical heads: features and applications

Unlike elliptical heads, torispherical heads have a convex central section and a reinforced transition zone. This design strengthens the edges and allows wall thickness to be reduced without compromising strength. In European projects, DIN and EN standards are applied, while international practice often follows ASME Section VIII together with ASTM A516 / ASTM A537, which regulate geometry, strength, and material requirements. Torispherical heads manufactured according to ASME standards reduce structural weight, simplify installation, and ensure resistance to high temperatures and aggressive environments.

FAQ

1. Can these heads be used in vertically oriented vessels?

Yes. Both types can be used in horizontal and vertical vessels, provided that loads and welded connections are correctly calculated.

2. Is an elliptical head suitable for equipment operating under vacuum conditions?

Yes. With sufficient wall thickness and proper calculation for external pressure, the elliptical shape demonstrates good resistance to deformation.

3. Are elliptical heads suitable for columns with a high content of suspended solids?

Yes, but in cases of intensive sedimentation, proper cleaning or drainage should be provided, as the head geometry does not completely prevent accumulation of solid particles.

Comments

Comment 1: Which type of head is preferable for large-diameter horizontal vessels?

Elliptical heads are often used because they provide more uniform stress distribution across a large cross-sectional area.

Comment 2: How does the type of head affect the vessel draining process?

Torispherical heads create a deeper central area that may facilitate removal of residual media. Elliptical heads allow smoother drainage when the vessel is installed with the appropriate slope.

Comment 3: What installation considerations arise when mounting instrumentation in the lower part of a head?

The torispherical shape may require extended nozzles or adapters due to the central curvature. Installation on an elliptical head is usually simpler because of its smoother radius.