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 centring 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 be 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 a 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