Safty valve for LP-gas (propane) and NH3 1.Max. Working Pressure: ... 4" 3.safety pressure valv Safety valve for LP-gas piping, dispenser, LPG station.when pressure increase beyond a ... , reducing excess perssure quickly for protecting the dispener, system.This is a distinct advantage over ordinary valve which ... valve for LPG dispenser . Rogo design. LP-gas safty valve for Propane,Anhydrous Ammonia , Rego