If you’re into do-it-yourself plumbing, you may have worked with compression fittings before. Otherwise, I will assume that you have heard of these things and yet you still have a lot of questions about what they are and how they work. That’s alright because today, I will be giving you valuable information about these plumbing essentials. Hopefully, you’ll be able to successfully accomplish your DIY projects or repairs with ease and perfection after reading this guide.

What are compression fittings?

Compression fittings are not only plumbing essentials but are also used in electrical conduit systems. Their primary function is to connect two similar, thin pipes or tubes together. In case two different pipes should be connected with each other (such as copper and PVC), the compression fittings will also be utilized with a couple of compatible materials to suit the connection. The reason why they’re so popular in the trade is because of their capability to make leak-free and airtight seals for different types of connections.

In plumbing, they are used in toilet stop valves, the part inside the toilet tank that’s responsible for moving the water into the bowl. These fittings are also utilized in hot and cold tap systems to prevent the fixture from leaking.

How do they work?

The compression fittings you use for your plumbing projects are relatively small. They are composed of an exterior compression nut and an interior compression ring which are commonly made from copper or brass materials. Compression rings are available in different shapes, too. However, they all have a common feature — the ring features beveled edges. These edges make the ring fit snugly into the nut.

To create an airtight and watertight seal, the compression nut should be tightened. Doing so will squeeze the two components of the fitting together, forming a sort of clamping force around the tubes or the pipes that are being connected.

On the other hand, large compression fittings do not make use of a single compression nut to create a tight connection. They make use of a flange that features a ring of bolts instead. For this type of fitting, the bolts are individually tightened in order to make the seal leak-free.

Quick Tips When Using Compression Fittings

Unlike other joints, compression fittings do not require thread sealants like plumber’s putty or Teflon tape. This is because there are no threads in the joint that need these sealants. Instead of threads, the connection is sealed with the use of a compression nut and a compression ring. These two parts are easily attached together because of the ring’s beveled edges. However, what you have to take note of is that compression fittings need adequate lubrication to prevent its two components from creating too much friction. The lubrication will also reduce the fitting’s rate of deterioration or wearing out. You can simply apply a small amount of grease on it in order to ensure its efficiency.

Another point to remember is that over-tightening of the nut is a big no-no. If you’ll do so, the ring might eventually deform which will then, of course, cause the fitting to not serve its purpose. A trade secret you might want to keep in mind as well is that the bigger the fitting, the less tightening it needs. The ring is quite sensitive and prone to damage so be very careful when handling and tightening the nut.