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 DIN EN ISO 5175-2
• 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