How to Connect a Check Valve

Determine the type and size of check valve most appropriate for your application. Oversized valves often result in valve chatter because they open and close too frequently. Undersized valves sometimes cause a pressure drop in the system, and might prevent adequate flow.

Shut off the water flow to the area of check-valve installation. An isolation valve is sometimes located between the water source and the check-valve-installation area. Use the isolation valve -- if it is present -- to turn off the flow of water. Shut off the water supply at the entrance into the building -- or at its incoming source -- if the system lacks an isolation valve.

Cut pipe at the check valve location, perpendicular to the length of the pipe. Use the check valve to help determine the amount of pipe to remove. Sand the burrs from the inside and outside of the pipe. Dry fit the check valve prior to permanent installation.

Swab primer on the exterior of the two pipe ends. Apply primer the interior of the check valve ends and let dry for at least 10 seconds. Swab cement on the exterior of the two pipe ends and on the interior of the check valve ends. Install the check valve, ensuring the flow direction is correct. Allow the cement to dry completely before returning water pressure to the system.