How to Troubleshoot a Check Valve Leaking Air

Check valves come in a few different designs. There is the ball check valve, disk or flap check valve, and cone check valve, to name the most common. The purpose of a check valve is to close off a pipe to prevent whatever is being transferred through the system from backflowing in the opposite direction. With a check valve in place, an obstacle is used to seal off a hose or pipe at a certain point to keep the flow from backing up. If this fails and there is a backup, the check valve is the first thing you should look at to determine if it is leaking.

Difficulty: Moderate

Instructions

Things You'll Need:

• Screwdriver

1. Shut down the air supply that is being sent to the leaking valve and remove the valve from the line.

2. Remove the screw from the valve assembly and lift weights and gaskets off. Pay attention to how these were placed so you can put the valve back together properly.

3. Check the nuts, screw, weights, and gaskets for wear and tear as well as rust. If needed, replace the items.

4. If it is a flap check valve, make sure it is closing properly. If it is a ball valve, inspect the ball to see if there are any worn areas. If it is a cone valve, look at the cone apparatus to see that it is sitting in the seal area with no gaps. If these parts are worn, replace them or the entire valve.

5. Check to see that the spring is pushing with the proper tension. Ball check valves sometimes have a spring inside that holds the ball up against the seat, helping to create the seal. If the spring is broken, worn down, or has lost its tension, it will need to be replaced.