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 ... designed to " pop" open to its full dicharge capacity, reducing excess perssure quickly for protecting the dispener, system ... valve for LPG dispenser . Rogo design. LP-gas safty valve for Propane,Anhydrous Ammonia , Rego