How to Replace a Sewage Pump Check Valve – drain the old check valve and saw it off the PVC sewage stand pipe.
This project is continued from Part 2.
Drain the Sewage Check Valve
The 12 feet of water in the pipe above the sewage check valve must be drained before removing the old check and ball valve combo. I could have simply stuck a screwdriver in the check valve to open it and let the water drain, but 12 feet of static water head tends to spray all over the place and I didn’t want to be in the splash zone. My solution was to hammer and fold the ends closed on a scrap section of 1/2 inch copper pipe and bend it in a V shape on the bench vise so I can stand clear of the water spray.
I poked the end of the copper pipe in the check valve to force it open. High pressure water gushed out in a spray from the 12 feet of vertical pipe. This photo was taken after the water has drained to illustrate the technique.
Sewage Check Valve Removal
With the wastewater drained from vertical pipe, I can now saw off the old sewage check valve above the PVC solvent weld connection. No measuring is required – the new valve will be fitted later and the proper adjustments made then.
The lower 5 feet of the 2 inch PVC sewage pipe is unsupported and I’ll need to hold the pipe with one hand to brace it while I work the saw with the other hand. I wired the old check valve handle to a 2×4 wall brace to prevent the valve body from dropping into the sewage basin. Fishing in the sewage basin for dropped items is not on my wish list!
Try to make the saw cut as square (even) as possible across the 2 inch PVC pipe. The old check valve is hanging by the safety wire here:
This is a closeup of the bottom of the swing check valve mechanism. The swing valve is hinged on one side and is partially open. The valve opens when the sewage pump runs and closes under the weight of the water head when the pump stops to prevent backflow.
The top end of the swing check valve is pictured below. This side of the valve holds back the wastewater. Overall, the PVC pipe and check valve body is remarkably clean after 3 years of service. This simple swing check valve mechanism is responsible for the water hammer as the 12 foot column of water reverses direction after the pump shuts off and slams the valve closed.
This project is continued in Part 4.
Thanks for reading,