API St 520-2 pdf download Sizing, Selection, and Installation of Pressure-relieving Devices Part II—Installation 1Scope This standard covers methods of installation for pressure-relief devices (PRDs) for equipment that has amaximum allowable working pressure (MAWP) of 15 psig (1.03 barg or 103 kPAg) or greater. Pressure-reliefvalves(PRVs) or rupture disks(RDs) may be used independently or in combination with each other toprovide the...