For 2:1 semiellipsoidal heads, the ASME Code equation is: where D is the inside diameter of the head. Example: Using the same vessel as in…

The ASME Code equation for spherical shells under internal pressure is: The calculated minimum thickness of formed heads is not rounded up to standard plate…

ASME Code, Section VIII, Division 1, uses an approximate equation for determining the required thickness of a cylinder subjected to internal pressure: where: t =…

Figure 400-4 gives equations for various components under internal pressure. Internal or external pressure produces a longitudinal-seam stress that is two times larger than that…

The purpose of hydrostatic testing is to reveal defects in the vessel workmanship and to detect the presence of leaks. Note that most weld defects…

See Section 600 for specific recommendations where service environments warrant postweld heat treatment (PWHT). PWHT is performed to reduce residual stresses, hold dimensional tolerances, improve…

Wet H2S cracking can occur at carbon steel equipment exposed to aqueous or “wet H2S” service. Wet H2S is defined as service conditions of at…

Design for brittle fracture is covered in detail in Section 500. At low temperatures, strength is less a consideration than the increasing susceptibility to brittle…

Code rules establish minimum construction standards for a pressure vessel. Because of the extremely wide scope of Section VIII, Division 1, however, higher quality standards…

It is important to understand that Code rules are formulated to provide minimum requirements for safety and service, and that the Code holds the owner/user…