Non Return Valves

A safe gas supply with gas non-return valves

WITT gas non return valves (Check valves) are used to protect plants, piping systems and outlet points against dangerous gas backflow and unwanted gas mixtures. Key features of WITT’s unique design are their very low opening pressures and very low pressure drop, so they are particularly suited to low operating pressure applications. A high-quality sealing system with elastomers prevents leaks. Dirt filters at the inlet ensure the long service life of these devices.

Non-return valves are also known as gas back-flow valves or check valves. WITT gas non-return valves can be installed in any orientation. They are available with various connections, in brass or stainless steel, and can be used for all technical gases such as oxygen, nitrogen, methane, hydrogen and compressed air. The WITT product range offers a wide selection of nominal sizes (up to DN 200) and flow rates (0.01 - 3,000 m3/h).

WITT gas non-return valves in thermal processing plants

WITT non-return valves conform to EN 746-2 and are particularly suitable for use in thermal processing plants. The low opening pressure of only 3 mbar and the high flow rate provide ideal protection for burner systems and prevent gas backflow and flashbacks.

WITT non-return valves can be installed in the air or oxygen line as well as in the fuel gas supply, thus reducing acquisition and storage costs. WITT non-return valves are 100% tested to DIN EN 5175-2 prior to delivery and offer the highest level of safety.

Safe biogas plants with WITT gas non-return valves / check-valves

In the air delivery lines to fermenters and biogas lines, WITT gas non-return valves are also characterised by their ultra-low opening pressures. WITT stainless steel valves for operation in biogas plants allow an air flow only in one direction and thus avoid unwanted and dangerous gas mixtures. Due to their low pressure losses, the use of small pipe cross-sections is possible, which reduces the operating costs for the compressor performance. WITT check valves are particularly leak-tight and therefore particularly safe. The valves are 100% tested and conform to DIN EN ISO 5175-2. The use of stainless steel in the gas return valves ensures a long service life, as these materials are extremely resistant to corrosion. They can also be retrofitted into existing air and gas supply lines.