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Pressure relief valves with PTFE-lining for corrosive media

LESER Critical Service pressure relief valves
  • Medium-touched components made of corrosion resistant PTFE

  • Pressure relief valve for the protection of highly corrosive media

  • Cost-effective alternative to high-alloyed materials

  • ATEX-compliant version in electrically conductive PTFE possible



LESER Critical Service pressure relief valves are designed, marked, produced and approved according to the requirements of the following regulations

ce-mark logo


asme logo
EAC logo

Valve Types

Type 447 >

PTFE-full lining at the inlet and outlet area for highly corrosive medium

DN 25 - DN 100 (1" - 4")

Type 449 >

Block body valve with flushing protective gas, all special materials available

DN 25 - DN 100 (1" - 4")

Technical Specifications for Critical Service

Nominal Diameter at Inlet

DN 25 - DN 100 | 1" - 4"

Actual Orifice Diameter d₀

23 mm - 92 mm | 0.91 in - 3.62 in

Actual Orifice Area A₀

415 mm² - 6.648 mm² | 0.645 in² - 10.304 in²


0.1 bar - 16 bar | 1.45 psig - 232 psig

Temperature (in accordance with DIN EN)

-85 °C to 200 °C | -121 °F to 392 °F

Body Material

1.0460, 1.0619 | SA 105, SA 216 WCB

Valve Connection

Flange in accordance with DIN EN 1092-1 and ASME B 16.5

Bellows Material (optional)

Stainless steel, PTFE, Hastelloy C276

Load Type




In our comprehensive download area you will find all necessary documents and detailed information on safety valves you need.

LESER critical service product brochure
View or Download
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