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Non-Return Valve NV400 intermediate flange version

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Non-return valve (intermediate flange version) for the prevention of unintended gas mixtures, for flow rates up to 8100 m³/h (air), up to 16 bar, for use in thermal processing plants, certified to EN746-2

  • with welding neck flanges for simple installing and removing
  • safety element: non-return valve [NV]
  • every non-return valve 100% tested
  • protects against flashbacks, for fuel gas-compressed air-mixtures
  • ultra-low opening pressures (approx. 3 mbar), ultra-low pressure drop
  • ideal for biogas desulphurisation systems
  • dirt filter (100 μm) on gas inlet
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WITT non-return valves for reliable protection against dangerous reverse gas flow. Now available also with welding neck flanges for simple installing and removing. Every non-return valve 100% tested.

Benefits

  • a spring loaded non-return valve prevents back feeding of gases which could lead to unwanted gas mixtures
  • low pressure drops – using complex valve assembly with low opening pressure – approx. 3.0 mbar
  • no leaks – using of a spring loaded valve assembly with elastomer sealing
  • stainless steel filter (100 μm) in the gas inlet protects the non-return valve against dirt contamination, extending the service life
  • dirt filter in gas inlet are replaced quickly and easily
  • 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
  • non-return valve as „intermediate flange version“ guarantees quick and uncomplicated removal and installation at replacement and annual testing
  • maximum flexibility – screwed non-return valve as well as installed between flanges. Complete (non-return valve + flange-set) or as add-on kit available
  • spacer tubes around threaded rods (M16) for secure centering of non-return
  • flange connection with weld-on connecting according to EN 1092-1 Type11
  • equal length in brass and stainless steel non-return valves for optimal interchangeability and combination with flange kits (as well as DN40 and DN50)

Operation / Usage

  • non-return valves are used to protect equipment and pipelines against dangerous reverse gas flow
  • use is possible for applications according to EN 746-2
  • non-return valves are tested to EN 730-2. They may also used as a safety device to protect against flashbacks (proved in accordance to EN 730-1 point 6.7) from combustion natural gas with air
  • WITT non-return valves may be mounted in any position / orientation
  • the maximum ambient / working temperature is 70 °C / 158 °F


Maintenance

  • annual testing of the non-return valve, body leak tightness and flow capacity is recommended
  • WITT is happy to supply special test equipment
  • non-return valves are only to be serviced by the manufacturer.The dirt filter may be replaced according to model by competent staff

Approvals
Company certified according to ISO 9001 and PED 2014/68/EU Module H
CE-marked according to PED 2014/68/EU
Cleaned for Oxygen Service according to EIGA IGC Doc 13/12/E: Oxygen Pipeline and Piping Systems

Non-Return Valve NV400 intermediate flange version is used in following areas:

Products

WITT Zentrale

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