Safty valve for LP-gas (propane) and NH3 1.Max. Working Pressure ... ZG1/4" 3.safety pressure valv Safety valve for LP-gas piping, dispenser, LPG station.when pressure increase ... beyond a predetermined point, the valve is designed to " pop" open to its full dicharge capacity, reducing excess perssure ... Safety valve for LPG dispenser . Rogo design. LP-gas safty valve for Propane,Anhydrous Ammonia , Rego