Compression Fittings

Compression fittings are designed for ease of replacement on all applications. If you are a do it yourself plumber, compression fittings are your friend.


Compression Fittings are used in electrical conduit systems and plumbing to connect tubes, pipe, or valve and fixtures together. Their main use is for applications that will eventually require the part to be replaced due to damage that naturally and inevitably occurs as a result of normal wear, or aging.


In most cases you can use compression fittings where you would normally sweat two copper pipes together for a water tight seal. Compression fittings need to be installed correctly for the seal to be water tight. The real advantage of using a compression fitting is that they are easy to disassemble and replace. They were designed to be utilized by the do-it yourself homeowner for replacement on refrigerator lines or basic plumbing applications.


The basic installation of a compression fitting consists of the following.


Slid the compression nut onto tubing, followed by the compression ring, and the pipe is then slid into the valve or fitting and the nut is tightened down. When you tighten down the compression nut, it will then compress the compression ring onto the seat; creating a (hopefully) water tight seal.


Compression fittings were designed to be used on stationary applications only and do not work well with rotational stress. By design they lock the tube or pipe inside the fitting, protecting against an outward pull. If you use a compression fitting in an application that could swivel or turn; like connecting an ice maker to a refrigerator, you will need to use a longer piece of tubing so that it absorbs the rotational stress caused if the unit is ever moved or turned.


These fittings are designed to ease replacement, but in most cases you will need to replace the compression nut, and cut the tube or pipe behind the compression ring. This will greatly improve chances of creating a new water tight seal for the application. When tightening an old connection, loosen the compression nut first and then if needed apply plumbers grease before re-tightening. If the seal is not leak proof, take the time to remove and replace the fitting.


Compression fittings should never be used on bent pipes; unless there is at least a few inches that are straight for the fitting to set. If you are connecting plastic tubing or pipe; make sure that you are using a plastic compression ring. Also do not use compression fittings to lengthen pipe or tubing; this will put the fitting in an area that could be subject to rotational stress.


There is also new push-in or push to connect compression fittings that work well with most applications. The difference in push-in fittings is that you do not need any special tools to connect. You will need to make sure that the pipe or tubing being connected is cut square before inserting into the fitting.


Push-in fittings can be reused; just like regular compression fittings. Be careful to make sure that they are the right type of fitting for the connection that you desire. When in doubt contact your plumber or the city code office for information on the proper fittings to use for each application or project.

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Published in: Do-It-Yourself


RSSComments: 6  |  Post a Comment
  1. Nice article

  2. Informative and well-written.

  3. If DIY project/job I’ve ever done has ended in disaster EricPinola .. these days I just call the expert plumber :-) A very straight forward guide for compression fittings.

  4. Every DIY project I meant .. damn it .. typing too fast! hehehe :-)

  5. Wow! You really do have a deep knowledge of diy info….you must be a pro. Well written and solid read.

  6. My parents made me read a LOT when I was a kid. Thnx- this article was to help promote my sales efforts for our company.


    Eric Pinola

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