How to Join a PVC Pipe to a Copper Pipe
While you should use more-expensive brass pipes for most of your plumbing, you can use cheaper PVC pieces if you need to update them. Just be sure to connect them together properly to avoid structural weaknesses. To learn how, read the guide below.
Step 1 – Turn off the Water
Before beginning, make sure that the water is shut off at the main supply valve or at the in-line valve connected to the pipes you are working on. Turn on the faucets to allow all of the water to flow out.
Step 2 – Prepare the Copper Pipe
Next, prepare the copper pipe. Use a rag to thoroughly dry the copper pipe both inside and out. Then, use an emery cloth to get rid of the top layer of copper, to provide a better bond. Make sure that the cut copper pipe is as smooth as possible. The pipe should be shiny for 2 inches from the cut end of the pipe.
Step 3 – Prepare the Copper Adapter
Use the emery cloth to sand the inside of the copper male adapter. Once you have finished doing so, the inside of the connector should be completely shiny.
Step 4 – Apply Flux
Apply flux by brushing it around the copper pipe and inside the copper male adapter. Make sure that the entire surface is coated properly to create the best bonding surface.
Step 5 – Fix the Copper Pipe and Connector
Next, fit the copper pipe and connector together. Slide the slip end down of the connector over the copper pipe until it won't go any further. Then, twist the connector around, so that all of the flux is distributed evenly.
Step 6 – Solder the Pipes
Warning: Use all proper safety precautions as provided by the tool manufacturers for completing this step. Wear appropriate safety gear, like gloves and a face mask.
Use a propane torch to heat up the slip joint. Then, when the flux has reached its melting point, you can apply solder to the joint. This solder should melt and connect the joints. Ensure all joints are sealed properly.
Then, wait until the copper pipe has cooled down and wrap the threaded section in plumber’s tape.
Step 7 – Add a PVC Adapter
Screw the PVC female adapter onto the copper male thread. Tighten it by hand until you can't turn it any more, and then finish the job with a pipe wrench.
Step 8 – Connect the PVC Pipe
If the PVC pipe isn't already cut, use a hacksaw to do so. Then, prime the cut PVC pipe and adaptor with “purple primer” for PVC pipes. Apply cement around the joint to ensure the pipes are completely bonded. Once you’ve coated the pipe and connector with cement, slide the pipe down as far as it will possibly go.