Non-Return Valve 70 / 70U

Non-return valve for the prevention of unintended gas mixtures, for flow rates up to 1120 m³/h (air), up to 16 bar, for use in thermal processing, certified to EN 746-2, G 3/4 - G 1.1/2

  • safety element: non-return valve [NV]
  • every non-return valve 100% tested
  • DIN EN ISO 5175-2
  • protects against flashbacks, for fuel gas-compressed air-mixtures
  • ultra-low opening pressures (approx. 4 mbar), ultra-low pressure drop
  • 62 X 137 X 160 mm, 1.255-1.679 g

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Information

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

Benefits:

  • a spring-loaded non-return 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. 4 mbar)
  • brass filter protects the non-return valve against flashbacks, extending the service life
  • 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 are used to protect equipment and pipelines against dangerous reverse gas flow. Use is possible for applications in accordance with EN 746-2
  • non-return valves are proved in accordance with DIN EN ISO 5175-2. They may also be used as a safety device to protect against flashbacks (proved in accordance with DIN EN ISO 5175-1 point 6.7), which may result from the combustion of natural gas/ LPG with air
  • 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

Approvals
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

Accessories

Test Rig 722

Test Rig 722

For the annual testing of WITT flashback arrestors and non-return valves

Pipeline Fittings

Pipeline Fittings

For flashback arrestors models 270N/NU and 623N/NU, as well as non-return valve model 70

Fittings

Fittings

For hose or pipe connection PN 10