(a) The user or his designated agent shall establish the design requirements for pressure vessels, taking into consideration factors associated with normal operation, such other conditions as startup and shutdown, and abnormal conditions which may become a governing design considerations (see UG-22).
The loadings to be considered in designing a vessel shall include those from:
NOTE: Italics added by Roy E. Hanson Jr., Mfg.
(a) internal or external design pressure;
(b) weight of the vessel and normal contents under operating or test conditions (this includes additional pressure due to static head of liquids);
(c) superimposed static reactions from weight of attached equipment, such as motors, machinery, other vessels, piping, linings, and insulation;
(d) the attachment of:
(2) vessel supports, such as lugs, rings, skirts, saddles, and legs;
(e) cyclic and dynamic reactions due to pressure or thermal variations, or from equipment mounted on a vessel, and mechanical loadings;
(f) wind, snow, and seismic reactions, where required;
(g) impact reactions such as those due to fluid shock;
(h) temperature gradients and differential thermal expansion;
(i) abnormal pressures, such as those caused by deflagration.