How to Splice a Copper Pipe

A man works on copper pipes.
What You'll Need
Copper valve or "T" coupling
Emery paper
Plumber's flux
Propane torch
Pipe cutter

Anyone who is doing minor plumbing may have to splice copper pipes together. Whenever there is the need for adding a new valve, water supply, installing a dishwasher, or adding a new outdoor water spigot, you will need to splice into the copper supply tubes. If you are facing the need to splice into a copper pipe, you can save a lot of money by doing it yourself.

Step 1 - Turn off Water Supply

Depending on where you need to splice the copper pipe, you will need to shut off the water valve to that area. A general rule of thumb is to splice into a water supply pipe that is fairly close to a shutoff valve. If not, then you will need to install one. In the instance where there is not a valve close by, you can shut the main valve off.

Step 2 - Drain Water from Lines

In order to make sure that you do not have a deluge of water come out when you cut into the pipe, turn on all the faucets in your home to drain the excess water from the pipes. Turn them off once the water stops running.

Step 3 - Cut Copper Pipe

When you splice into a copper supply line, you usually are adding a new line. To do this, you must first cut the existing line. A pipe cutter looks much like a clamp with two small blades in the middle. You place the cutter on the pipe and tighten the knob. As you turn the cutter, continue to tighten the knob. This presses the blades into the pipe, cutting through it.

Step 4 - Clean All Cuts With Emery Paper

Once the cuts have been made, run some emery paper over all of the ends. You should do this for both the pipes that you cut and for the new coupling.

Step 5 - Apply Flux to Pipe

Flux is something that is needed to help make a watertight seal when the solder is applied. It is applied with a small brush that is included with the flux. Apply it to the inside edge of the pipe that was cut. Also apply it to one side of the "T" coupling or valve.

Step 6 - Solder Copper Pipes Together

Place the coupling over the copper pipe and press it until it stops. Hold the propane torch up to the joint and heat it. This should only take a few minutes before it is ready to apply the solder. Hold the solder up to the heated joint and touch it to the pipe. It should melt and be sucked around the pipe and fill the joints. Repeat this process with other end of the coupling.

Step 7 - Turn Water on And Test

After the splice in the copper has been completed, turn the water on and test for any leaks. If there is some leaking, turn the water off, drain the lines, and apply more solder.