PASS/EQUIP → Working with PASS/EQUIP → Data input → Dished head
Fig. 1. Ellipsoidal head
Component name, code of standards, dimensions according to GOST, material, dimensions, weld strength factors, insulation and lining, and load properties for dished ends are set in the same way as those for cylindrical shells.
At calculation of loads using FEM method, dished ends are represented as a pair of weightless beam elements with node in the point, which corresponds to the head gravity centre (Fig. 2). Cross-section of elements is considered to be constant and corresponding to the cross-section of the head foundation. Head weight is considered to be lumped and is applied to the centre of gravity (yellow node).
Fig. 2. Modeling a dished head with beam elements
Fig. 3. Hemispherical head
Fig. 4. Torispherical head
Torispherical head type is determined according to GOST 34233.2-2017 (GOST 14249-89) and can be seamless pressed, welded from flat bars or welded from segments (Fig. 5). Weld strength factors must be set welded heads.
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| Seamless | Welded from flat bars | Welded from segments |
Fig. 5. Torispherical head types