According to API 2000 code, the pressure & vacuum relief valve of Model KSBB and KSBS are designed, manufactured and tested.Model KSBB, which is used for the protector of fluid storage tank, is
composed of one body with the functions of pressure relief and vacuum relief. (Model KSBS is used for the pressure setting above 1 PSIG)This valve has function to intake the air under constant
pressure during unloading, and to discharge the overpressure generated during pouring the fluid into storage tank.This is the safe valve to control the deflation(vacuum) and inflation(pressure) of
several storage tanks.