A Relief Valve or Pressure Relief Valve (PRV) is a type of Safety Valve used to control or limit the pressure in a system; pressure might otherwise build up and create a process upset, instrument or equipment failure, or fire.

The pressure is relieved by allowing the pressurised fluid to flow from an auxiliary passage out of the system. The relief valve is designed or set to open at a predetermined set pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits. When the set pressure is exceeded, the relief valve becomes the “path of least resistance” as the valve is forced open and a portion of the fluid is diverted through the auxiliary route.

Sizes DN15 to DN300 (NPS 1/2 to NPS 12)
Pressure Rating Class 150, 300, & 600
Material Construction Cast Carbon Steel – WCB, WCC, etc.
Austenitic Stainless Steel – CF8, CF8M, CF3, CF3M, CN7M, CG3M, etc.
Design & Manufacturing Standard API 520
Face to Face Std. ASME B16.10
End Connection Std. ASME B16.5
Testing Standard API 527
End Connection Type Flanged Ends, Screwed Ends, Socket Weld Ends, etc.
Operated Type Wrench Operated
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