Non-return valves

The task of non-return valves or backflow valves is to prevent the flow of the media in a certain flow direction.

Our product range covers all non-return valve models used in the industry. They can be divided into four groups.

The most conventional model is a flanged or welded non-return valve. Up to PN 40, these non-return valves are ARI valves, and the welded high-pressure non-return valves up to PN 500 are STRACK valves. The flanged non-return valves in our product range are from GESTRA. According to the nominal size, pressure rating and, above all, pressure loss, a non-return valve suitable for a certain process can be selected from our product range of Disco, flap non-return valves or dual-butterfly non-return valves.

It is also important that non-return valves are dimensioned and not selected based on the pipe size only. Dimensioning ensures correct opening and closing of the valve as compared to flow rate. Excessive nominal size and low flow rate can result in a situation where the non-return valve never fully opens and its wear parts are subject to constant mechanical stress. This is often manifested by so-called continuous clinking. Naturally, this reduces the service life of the valve. For such applications, we particularly recommend the DSF-type non-return valve manufactured by ChemValve, the structural solution of which prevents the aforementioned problem and the design of which grants significantly better transmission as compared to a conventional non-return valve of the disc type.

Our product range also covers ASME non-return valves up to the pressure rating of 2500#, as well as non-return valves that can be locked in the open position.

Additional information on non-return valves is available in the Gestra general brochure.

Also, listen to our concise webinar presentation Choice and dimensioning of non-return valves