The swing check valve is a self acting one way flow control valve which consists of a main valve body, a swinging internal disc and a shaft with a disc arm that hold the disc in position. This is the standard design. A lever arm and counterweight can also be affixed to the external side of the valve shaft. This allows some control of the disc opening/closing speed and also indicates the position of the disc inside the valve.

The main use for these valves is at the outlet side of the pump in a water or waste water pipeline.

When the flow begins, the valve disc is pushed forward by the force of the water flow against the valve disc. The flow continues its travel in the direction of pumping. At full flow, the check valve disc is fully open and makes contact with the body stop inside the valve. At this point there is then a clear flow inside the pipeline – with minimal head-loss, thereby increasing the efficiency of the pipeline.

As the pump begins to slow down to the stop position, the check valve disc begins to close. As the pump stops, the check valve closes quickly and automatically by means of the weight of the disc under gravity forces and also by the assistance of the lever and weight. The closure is also further assisted when the flow of water stops and tries to flow in the reverse direction upstream of the valve and this back flow of water helps to seal the valve by pushing the valve disc seat tightly onto the valve body seat.

This rapid closure of the check valve prevents the water in the pipe line flowing in reverse back to the pumps.

The full open angle of the disc should not exceed 70 degrees.

The check valve should be installed with the shaft in the horizontal position. When installed in vertical pipes – the flow direction can only by upwards, and the lever and weight, if fitted, should be set accordingly.

There is no need for maintenance for these check valves that are installed especially in clean water pipe-line. If check valve is uninstalled, shaft o-rings can be checked and renewed accordingly.

Available Accessories

Mechanical Limit Switch : A cam, which is fixed on shaft of check valve, rotates as the disc flaps. When disc closes, cam hits on switch. Switch sends signal to panel at operation room to notify closed position of disc.

Shaft Protection : It is a steel pipe to protect open-end of valve shaft from any damage.

Mesh Guard : It is a protective accessory for the things around the valve against sudden movement of counter lever and weight under operation.

By-pass : It is a “U” shaped equipment fixed on body, which connects outlet of check valve to inlet from outside of main pipe line. There is a gate valve between two elbows. In closed position of disc, by-pass valve is used to transfer the fluid from outlet side to inlet side. If chamber of pump is emptied, fluid can be transferred into the pump.