Critical-Service - Pressure relief valves with PTFE-lining | LESER
Critical Service
Critical Service Pressure Relief Valve from LESER

Pressure relief valves with PTFE-lining for corrosive media

  • 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:

  • LESER CE Approvel
  • LESER ASME Approvel
  • LESER EAC Approvel
  • LESER Chinese TS Approvel

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 data 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
Valvestar from LESER


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