Install Compression Fittings
Pipes, fixtures and valves for common plumbing can be connected in various ways. The easiest way to connect a pipe to another pipe, a fitting or a valve is with a compression fitting. These fittings are designed to create fluid tight seals by compressing a semi-rigid ring so it spreads out in the gap between the 2 parts and securely fills that gap. While these fittings are easy to install or replace, they do not create a lifetime seal and will therefore need to be replaced from time to time. Care must be used when installing a compression fitting to ensure that a proper fluid tight seal is achieved. Use these tips to learn how to install compression fittings.
Contents
Steps
Determine the Suitability of Compression Fittings For the Application
- Use compression fittings in confined areas, such as under sinks. Welding in these areas can be awkward and dangerous.
- Apply compression fittings to joints that will not be moved after the joint is made. Compression fittings will not provide mechanical support to the parts connected by the compression fitting.
- Consider compression joints to lengthen pipes. This is generally not recommended because of the lack of mechanical support provided by the compression fitting. Compression fittings may be appropriate to lengthen pipes in congested areas where the pipes are supported by something other than the compression fitting and will not be moved after the joint is made.
- Ensure that plastic will be fitted to plastic or metal will be fitted to metal. Do not attempt to use compression fittings to join metal pieces to plastic pieces.
- Ensure the compression fitting can be made on straight sections of pipe. Compression fittings will be difficult, if not impossible, to apply if there is a bend in the tubing close to the joint.
- Save the joint, rather than replace it. Properly assembled compression fittings will have turns left over on the compression nut, so a leaking valve might be saved rather than replaced. Turn the compression nut a quarter turn at a time to attempt to stop the leak.
Gather the Parts
- Acquire the compression fitting. Compression fittings can be found at most hardware stores. They typically consist of a valve or fitting that has been designed to receive a compression joint, a compression ring and a compression nut.
- Make sure the parts are new. Do not attempt to reuse old compression rings or compression nuts if an existing compression fitting is being replaced.
Install the Compression Fitting
- Place the compression ring on the pipe. Slip the end of the compression ring onto the end of the pipe that will meet the other piece. Slip the ring on just far enough to see that the pipe is fully through the compression ring.
- Insert the pipe into the other piece. Firmly push the end of the pipe that has the compression ring on it into the other piece of the compression fitting. The compression ring will slide further onto the pipe as it enters the fitting. Make sure that you feel the pipe pressing hard against the other piece, rather than simply feel the force needed to push the pipe further through the compression ring.
- Tighten the compression nut. Tighten the compression nut using your fingers. Use a pair of pliers to turn the compression nut another half turn from the point of finger tightness.
- Turn on the fluid supply and check the fitting for leaks. If leaking is observed, continue to tighten the compression ring using the pliers by a half turn at a time until the leak is stopped.
Tips
- If problems occur in getting a fitting that does not leak, try removing the pipe from the fitting and wrapping the compression ring in 2 to 3 layers of PTFE tape, which is readily available in hardware stores. With the tape in place, reinstall the pipe into the fitting.
Things You'll Need
- Compression fitting
- Pliers
- PTFE tape
