Standard: API, DIN, JIS, GB, ASME Ⅷ, API std 526, API RP 520Material: Stainless Steel, Carbon Steel, Brass, Alloy Steel, Titanium, 904l, Ductile Iron, Cast Iron, Cast Steel. ?Size: 1/2" ~18", DN15~DN450.Pressure: 150LB~2500LB, PN10~PN420.?Type: Full Lift, Balanced Bellow, Bellow Seal, Flanged, Steam Jacketed, Low Tempreature, High Tempreature, Power Station.?Safety valve is a valve mechanism which instantly releases a substance from a boiler, pressure vessel, or any other system, once the pressure or temperature exceeds preset limits.It is among a group of pressure safety valves (PSV) or pressure relief valves (PRV), that also includes relief valves, safety relief valves, pilot-operated relief valves, low pressure safety valves, and vacuum pressure safety valves.Safety valves were first utilized on steam boilers throughout the Industrial Revolution. Early boilers operating without one were vulnerable to accidental explosion.Vacuum safety valves (or combined pressure/vacuum safety valves) are utilized to prevent a tank from collapsing even though it is being emptied, or when cold rinse water can be used after hot CIP (clean-in-place) or SIP (sterilization-in-place) procedures.