Fire retardant breathing valve in the system from the security role. When the system pressure exceeds the set value, the safety valve Ting open, will be part of the system of gas into the atmosphere, so that system pressure does not exceed the allowable value, thus ensuring the system is not an accident due to the pressure is too high. Safety valve, also known as the relief valve. Icon for some of the typical structure of the safety valve. Figure a piston valve spool is a tablet. Gas source pressure on the piston A, when the pressure exceeds the safe value determined by the spring force, the piston A was to open the top part of the compressed air into the atmosphere from the valve port; when air pressure falls below a safe value, the spring-driven piston down, close the valve port. 
 Nominal pressure: PN0.5-16Mpa 
 Operating temperature :0-550 ℃ 
 Nominal diameter: DN15-150mm 
 Connection type: flanged, threaded, welded 
 Material: 304,316,304 L, 316L, SS316, WCB, WC6, WC9, CF3, CF8, cast steel, cast iron, ductile iron, forged steel, stainless steel and so on.