How to Install Electrical PVC Expansion Coupling

PVC expansion couplings are used at any point where the expanding or contracting of one side of the pipe is a concern. The couplings allow the PVC to move along with the expansion rather than putting stress on the joint. They come in any size in which the PVC is available. A PVC expansion coupling consists of two pieces of PVC pipe, one slightly larger than the other, that slide together freely. Any time PVC extends from underground to attach to a point above ground, an expansion joint is needed to allow for the movement of the earth from ground freezing and thawing.

Working with PVC requires a few special materials, such as PVC glue.

Step 1

Locate a point between where the PVC leaves the ground and where it enters a wall or joins with a junction box. Be sure there is sufficient space for the expansion joint to be installed.

Step 2

Using a hacksaw, cut the PVC coming out of the ground at the place where the expansion joint is to be installed.

Step 3

Apply some PVC glue to the outside of the pipe coming from the ground.

Step 4

Position the half of the expansion joint set with the smaller opening on the end of the pipe emerging from the ground and slide it over the pipe, making sure the pipe slides in completely.

Step 5

Slide the side of the expansion joint with the larger opening onto the smaller piece of the expansion joint set. The larger side must always be on top to prevent water from entering the area between the two pieces of the expansion joint.

Step 6

Apply PVC glue to the piece of PVC that will go into the top of the expansion joint. When you secure this pipe, make sure the two pieces of the expansion joint are about halfway through their total possible travel. You do not want the top piece resting on the bottom one. This would prevent the joint from sliding, thereby rendering it useless.

Step 7

Continue installing the PVC until you reach the point of entrance into the wall or the desired junction box.