Gate valve has one way for fire safe.That is leakage from the valve stem area is prevented by double o-ring sealing、packing and firesafe gasket. Leakage through the
gate valve body joint is also blocked by double o-ring sealing and body gasket. After a fire has deteriorated o-rings, gland gasket, body gasket and stem, fire safe packing is the feature that prevents external fluid leakage.