Step 6 · Install the PVC Section with Transition Couplings

This is the step most people slow down on. Take it one move at a time — there’s no rush, and you can rewind the clip as many times as you need.

Slide one of the flexible couplings completely onto one of the cast iron pipe ends. On the other cast iron pipe, slide the second coupling on but then roll the rubber gasket back over itself, exposing the inside of the coupling. Now, insert one end of your new PVC pipe fully into the first coupling until it hits the internal stop. Carefully flex the PVC pipe into position and guide the other end into the second coupling. Once it's in place, unroll the rubber gasket so it sits flat against the PVC pipe. Adjust the PVC pipe and both couplings so that everything is aligned and the pipe is seated against the stops in both couplings. The metal shields should be centered over the rubber gaskets.