I must design a jacketed vessel (Fig. 9-2, Type 1) acc. to Div. 1.
Design data for
shell : FV / 40 psi @ 284°F
jacket : 40 psi @ 284°F
So part of the schell must be designed for 55 psi.
As I understand UG-99 (e), we must hydrotest the jacket based on this differential pressure (1.3x55xstress...