Wastewater Swing Type Check Valves, Metal Seated

A swing check valve is a valve having a mounted disc that swings on a hinge or shaft. The disc swings off the seat to allow forward flow and when the flow is stopped, the disc swings back onto the seat to block reverse flow. The shut-off characteristics of the valve are impacted by the weight of the disc and the return flow. The disc of the valve is there to block the flow, swings on a hinge or trunnion, either onto the seat to block reverse flow or off the seat to allow forward flow.

The seat opening cross-section may be perpendicular to the centreline between the two ports or at an angle. The swing type check valves can come in several sizes but the large-sized ones are mainly considered. For applications in firefighting and fire life safety systems, another variant of this mechanism the clapper valve is used. In that valve, only a hinged gate remains open in the inflowing direction and it often comes with a spring that keeps the gate shut in absence of forwarding pressure.

For achieving optimum performance, sometimes a lever and weight or a lever and spring are mounted. Swing check valves with lever and weight are appropriate for installations with an increased risk of water hammer at standard velocities. And Swing check valves with lever and external spring are suitable for high pressure, insufficient backpressure, and high flow velocities.

The swing check valves offered by us are designed for providing easy maintenance. The bonnet assembly including hinge and disc can be removed from the body easily by just unscrewing a few bolts and maintenance can be performed.

A minimal amount of force is required by the light-weight disc of EPDM rubber with lip sealing and steel insert to open and close the valve. The disc is mounted in a nylon bushing that allows it to move slightly both horizontally and vertically to close completely tight. The hinge is made of acid-resistant stainless steel and is firmly tightened around the shaft with bolts to eliminate play and thus to ensure durability. The conventional swing type check valves are used in horizontal or vertical systems with the rising flow for preventing flow reversal. They are ideal for multi-pump sewage water applications that have low to medium lift.