How do you define a hydro-test pressure based on design pressure?

Hydro-test pressureandholding times vary for different design codes. For example, the ASME SEC VIII Div.1 general hydro-test pressure will be1.3 x design pressure (minor factors may vary for this equation as well) and forpiping design codes, the hydro-test pressure will be ASME B31.4,B31.8 1.5 xdesign pressure.

Bellows of an expansion joint going through a hydro-test pressure.