Pilot-operated Pressure-relief Valves are composed of Pilot Assy and Main Valve. Although Spring-loaded Pressure-relief valves adopts the force of the spring against the inlet pressure, the reliving pressure and reseating pressure of the Pilot-operated Pressure-relief Valves is controlled by Pilot Assy, which acts nearly as same as Spring-loaded Pressure-relief valves. There is no adjusting function in the Main Valve.
Pilot-operated Pressure-relief Valves have larger size variations compared to Spring-loaded type, which is applied in a severe condition such as high pressure.
  • Pilot Operated Safety Valve:
  • Piping between the pilot and main valves is integrated into the cover to prevent damage and freezing
  • Integrated Backflow Preventer as standard part
  • Four week delivery time from the factory
  • Higher capacity than comparable size with extra orifices
  • 20% less installation space than competitors' comparable models
  • Supplementary Loading System:
  • Higher operating pressures are possible
  • Closing pressure difference of up to -3 %; opening process is independent of back pressure
  • Functional test and valve adjustment possible during operation
  • Overpressure tolerance at a minimum of 1% with Pop Action


Nominal Diameter at InletDN 25 - DN 200 | 1" - 8"
Orifice1 D 2 to 8 T+ 10 | 1 D 2 to 8 T+ 10
Actual Orifice Diameter d011 mm - 180 mm | 0.433 in - 7.087 in
Actual Orifice Area A095 mm² - 25,446.9 mm² | 0,147 in² - 39.443 in²
Pressure2,5 bar - 426 bar | 36 psig - 6170 psig
Temperature (iaw DIN EN)-45 °C to 200 °C | -49°F to 392°F
Body Material1.0619, 1.4408 | SA 352 LCB, SA 216 WCB, SA 351 CF8M
Valve ConnectionFlange in accordance with DIN EN 1092, ASME B 16.5 or JIS 2220
Load TypeMedium Controlled
Pilot Operated Pressure Relief Valves