After a new vessel has been installed, what must be done in order accept the vessel for operation?

When a corroded area of considerable size is encountered and the circumferential stresses govern, what is maximum length over which the thickness can be averaged for a vessel with an inside diameter of 48 inches?

The API authorized pressure vessel inspector may give prior authorization for repairs that do not involve:

An internal inspection is required on above the ground 'Lower-risk' vessels:

Flush (insert) patches shall be installed with full penetration butt joints and the corners shall be what type?