Pressure Release Valve: Functioned to release the pressure in pipeline which is in excess of the safe preset value of pilot valve, and to maintain in the pressure in pipeline below a certain safe value, thus to prevent pipeline equipments from damage due to high or sudden pressure. This valve is used to release the pressure of fire control test circulating system in high-rises to prevent the system from danger due to excessive hydraulic pressure. Pressure holding valve: Functioned to maintain the water supply pressure at the upper stream of main valve over a certain preset value. Emergency Open Valve: Mounted at the water outlet of fire spraying pump, it will immediately open when the pressure at pump outlet rises over a certain preset value. Specifications 1) Diaphragm type: DN50-DN350 Piston type: DN400-dn800 2) Pressure grade: PN10, PN16, PN25 Main materials: 1) Body and bonnet: Cast iron, ductile cast iron, WCB, WCA, WCC, A351, 304, 340L, 316, 316L17-4PH 2) Disc: Brass, stainless steel, carbon steel 3) Stem: Stainless steel
