Non-Return Valve NV100

Non-return valve for the prevention of unintended gas mixtures, for flow rates up to 11,059 scfh (air), up to 362 psi, G 1/8 - 3/8

  • safety element: non-return valve [NV]
  • every non-return valve 100% tested
  • ultra-low opening pressures (approx. 0.0296 psi), ultra-low pressure drop
  • compact and light: 0.98 X 2.77-3.78 inches, 1.56 oz

This model is also available in Stainless Steel

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    WITTnon-return valves (check valves) for reliable protection against dangerous reverse gas flow.
    Every non-return valve (check valve) 100% tested.

    The best non-return valves (check valves) in the world.


    • a spring-loaded non-return valve (check valve) prevents a reverse flow of gases, which could lead to unwanted gas mixtures
    • low pressure drops – using complex valve assembly with low opening pressures (approx. 30 mbar)
    • no leaks – using a spring-loaded valve (check valve) assembly with elastomer sealing
    • diverse applications – useful for many technical gases
    • reduce installation costs – the spring-loaded valve is not affected by gravity and may be installed in any orientation

    Operation / Usage:

    • non-return valves (check valves) are used to protect equipment and pipelines against dangerous reverse gas flow. Use is possible for applications according to EN 746-2
    • WITT non-return valves (check valves) may be mounted in any position / orientation
    • the maximum ambient / working temperature is 60 °C / 140 °F


    • annual testing of the non-return valve (check valve) and body leak tightness is recommended
    • WITT is happy to supply special test equipment
    • non-return valves (check valves) are only to be serviced by the manufacturer

    Company certified ISO 9001
    Designed for Oxygen Service according to EIGA IGC Doc 13/12/E: 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


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    Test Rig 722

    Test Rig 722

    For the annual testing of WITT flashback arrestors and check valves