Non-Return Valve 800-ES

Non-return valve, stainless steel, for the prevention of unintended gas mixtures, up to 4,351 psi, 1/4" NPT

  • safety element: non-return valve [NV]
  • every non-return valve 100% tested
  • also ideal for use with corrosive gases
  • compact and light: 0.68 X 2.73 inches, 29.20 oz

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WITT non-return valves for reliable protection against dangerous reverse gas flow. Every non-return valve 100% tested.


  • a spring-loaded non-return valve prevents a reverse flow of gases which could lead to unwanted gas mixtures
  • no leaks – using of a spring-loaded valve assembly with elastomer sealing, opening pressure approx. 2 bar
  • diverse applications – useful for many technical gases

Operation / Usage:

  • non-return valves are used to protect equipment and pipelines against dangerous reverse gas flow
  • ideal for use with corrosive gases in the chemical industry, process technology or in laboritories
  • WITT non-return valves may be mounted in any position /orientation
  • the maximum ambient / working temperature is 150 °C / 302 F° (max. 60 °C / 140 °F at oyxgen)


  • annual testing of the non-return valve and body leak tightness is recommended
  • non-return valves are only to be serviced by the manufacturer

Company certified to ISO 9001 and PED 2014/68/EC Module H
CE-marked in accordance with PED 2014/68/EC
Designed for Oxygen Service in accordance with EIGA 13/20 and CGA G-4.4: Oxygen Pipeline and Piping Systems
Cleaned for Oxygen Service in accordance with EIGA 33/18 and CGA G-4.1: Cleaning of Equipment for Oxygen Service


Test Rig 722

For the annual testing of WITT flashback arrestors and check valves