Compression fittings are the traditional quick-connect fitting. While these fittings require a little more effort to install, they still provide strong, tight, and dependable seals for any of your water treatment configurations. John, our Master Water Specialist, shares his knowledge of compression fittings to help you better understand how they work and how to install them correctly.
What exactly is a compression fitting?
A compression fitting is one of the beast fitting's components into another, usually tubing, to create a watertight seal between two different lines. The compression fitting has become less common in the water treatment industry since the introduction of quick-connect style fittings, but it is still a great fitting that can handle high pressure and provide a reliable, tight seal. A compression fitting is made up of three parts: a sleeve, a nut, and the fitting body itself. When the nut compresses the sleeve into the fitting body, it acts as a seal.
How do you put on and take off a compression fitting?
Compression fittings are simple to install, but most of the time a wrench is required. They are made up of three parts: the sleeve, the nut, and the fitting body. All of the components work together to form a watertight seal. To make this seal, you must first:
- Insert the nut into the tubing.
- Slide the sleeve up to the threaded side of the nut.
- Insert the tubing into the fitting body's connector and pull the nut, then the sleeve, down until the threads on the nut meet the threads on the fitting body.
- The nut will then be screwed onto the fitting body.
- Tighten the connection with your wrench.
Simply reverse the process to remove the fitting. When you remove the sleeve from the fitting body, it will stick to the tubing. You can reuse the sleeve if you simply put it back into the fitting body or connect the same tubing to a different angle-stop configuration. If you are not connecting the tubing to another type of compression fitting, you must cut the sleeve off to remove it from the tubing.
What materials are compression fittings made of?
Compression fittings are available in a number of materials. The most common material for a compression fitting is brass, but you must ensure that you purchase lead-free brass fittings because it is illegal in the United States to use any fitting that contains lead. They are frequently made of plastic and stainless steel. The amount of pressure or temperature that your fitting can withstand will vary depending on the material or your fitting.
How do compression fittings work?
Compression fittings have a wide range of applications. A compression fitting is used anywhere a waterline or air pneumatic line is connected. If you're just connecting drinking water systems, you'll probably use a quick-connect or quick-disconnect fitting.
A compression thread is represented by the angle stop beneath your sink. To connect to a coffee brewer, for example, these flex lines will frequently use compression-type threads. Some have a faucet connection on one side and an angle-stop connection on the other, which is your compression thread. To attach tubing to the top of an angle stop, simply use a compression nut and sleeve. All of these fittings connect in the same way.
What is the maximum pressure that a compression fitting can withstand?
The amount of pressure that a compression fitting can withstand is straightforward. A brass fitting will typically withstand more pressure than a plastic fitting, and so on. Typically, the pressure rating of a fitting can be found online or on the packaging that it comes in.
What should you do if your compression fitting leaks?
If a compression fitting leaks, you must locate the source of the leak. If you have a sound connection, have properly assembled the fitting, and have wrenched it down to where it is good and tight, the fitting is unlikely to leak. The seal should be tight and complete unless a piece of tubing is moved, putting some strain or torque on the fitting itself.
Plastic fittings may be more prone to leaking after installation, but this is usually due to something externally altering or stressing the component. Excessive vibration can cause plastic components to fail. If you use a fitting on an appliance or piece of equipment that has a pump or a motor that causes vibration, the nut may come loose from the fitting body.
Turning off the water is the best way to stop a leak with this type of fitting. After that, you'd need to disassemble the fitting and reassemble it after inspecting it for any flaws. Hopefully, your leak will stop after reassembling. If not, you may need to replace the fitting, or a portion of it, as well as the tubing that was attached to it.
