As soft as copper pipe is, the best way to connect it to these pipes or to fittings is with the use of copper pipe compression fittings. With the right tools, materials and instructions, even an inexperienced do-it-yourselfer can complete this common type of connection in minutes.
Step 1 – Cut Your Pipe
You'll need your pipe to be a specific length, so measure the length you'll need. Unless you already have the perfect size for your needs, use a copper pipe cutter to cut the length of pipe according to your measurements.
Step 2 - Turn Off Water
Remove any water from the pipe on which you're working. Find the valve or tap that controls the flow of water through your pipe, and turn it off.
Step 3 – Connect the Fitting
Connect the fitting by slipping the fitting nut over the copper pipe, followed by the copper ring. Slip the end of the pipe into the male end of the fitting, and screw on the nut. When it begins to bind, use 2 wrenches to finish tightening it: one wrench to hold the pipe, the other to turn the nut. When the connection is tight, turn on the water, and check to make sure there are no leaks at the connection.