Fibre-optic temperature measurement systems

The NV range of Gas non-return valves from Witt Gas Techniques, the Warrington based gas safety, control, mixing and analysis supplier, are safety devices designed to stop the return flow of gase.

The NV range of Gas non-return valves from Witt Gas Techniques , the Warrington based gas safety, control, mixing and analysis equipment supplier, are safety devices designed to stop the return flow of gases in gas supply pipelines used in shipyards, gas production plants, treatment works and gas distribution systems.

There are 6 models in the range comprising NV100, NV200, NV300, NV400, NV800 and NV2000 with flow ranges up to 26,800 m3/hour.

All are designed to be installed in any orientation, as the spring loaded valve is not affected by gravity (except NV2000) with opening pressures as low as 4 mbar even when mounted in the vertical plane.

They can be used in pipelines supplying butane, hydrogen, methane, natural gas, LPG, propane, compressed air and non-flammable gases to prevent flammable mixtures being formed.

The valve mechanism in the NV100, NV200, NV300 and NV400 is protected against contamination by a mesh dirt filter in the inlet and are suitable for use with most non-corrosive gases.

The NV100 has a maximum working pressure of 25 bar, whilst the NV200, NV300 and NV400 have a maximum working pressure of 16 bar.

The NV800 and NV2000 are used when oxygen or compressed air is used at equal or higher pressures than the fuel gas.

They operate with a maximum gas pressure up to 10 bar.

Witt Gas Techniques recommend that all their non-return valves should be tested at least once a year for function and body leakage and should be serviced by Witt Engineers or one of the Company's approved repairers.

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