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LESER UK Product Page for Pilot Operated Pressure Relief Valves


Solutions for high plant efficiency

LESER Pilot Operated Pressure Relief Valves for High Efficiency

Pilot operated pressure relief valves

  • Highest blow-off capacity of all series

  • Tightness right up to set pressure

  • Operating pressures up to 96% of the set pressure

  • Back pressures up to 70% of the set pressure

  • Backflow preventer integrated as a standard component 

  • Integrated Piping prevents damage and freezing

Supplementary Loading System

Equipment that enables the following pressure relief valve characteristics:

  • Tightness right up to set pressure

  • Operating pressures up to 97% of the set pressure 

  • Low loss of medium due to short opening times

  • Function test and valve adjustment possible during operation

  • Suitable for all media temperature



LESER High Efficiency pressure relief valves are designed, marked, produced and approved according to the requirements of the following regulations:

ce-mark logo
asme-uv logo


EAC logo

Valve Types

Type 811 >
Pilot operated / Pop Action

DN 25 - DN 200 (1" - 8")

Type 821 >
Pilot operated / Modulate Action

DN 25 - DN 200 (1" - 8")

Type 702, 712, 714, 731 >
Supplementary Loading System (additional option for safety valves)



Access all the necessary documents and detailed information for pressure relief valves in our download area

View or download the high efficiency product catalogue

Technical Data for Pilot Operated Pressure Relief Valves

Nominal Diameter at Inlet

DN 25 - DN 200 | 1" - 8"

Actual Orifice Diameter d₀

11 mm - 180 mm | 0.433 in - 7.087 in

Actual Orifice Area A₀

95 mm² - 25,446.9 mm² | 0.147 in² - 39.443 in²


2.5 bar - 426 bar | 36 psig - 6170 psig

Temperature (in accordance with DIN EN)

-48 °C to 200 °C | -54.4°F to 392°F

Body Material

1.0619, 1.4408 | SA 352 LCB, SA 216 WCB, SA 351 CF8M

Valve Connection

Flange in accordance with ASME B 16.5 or DIN EN 1092

Load Type

Medium controlled

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