Pipe fittings thread together to connect pipes and help you configure your plumbing system. Jason Bordash, one of our Senior Water Specialists, helps you understand different types of pipe fittings and how they're used.
What is a pipe fitting?
A pipe fitting is a threaded fitting that comes in different shapes to make different plumbing configurations. Pipe fittings include tees, elbows, y-fittings, couplings, reducers.
What are pipe fittings used for?
A pipe fitting joins pipe and plumbing configurations. If you were to plumb your entire house, you would need a pipe fitting at different parts of your house to branch off the water supply or bend with the water supply so that the water goes around a corner.
What are the different pipe fittings and how do they work?
Elbows bend water at 90 degrees or 45 degrees. The pipe comes in on one end and goes out another to make a 90-degree bend in the plumbing configuration. You use elbow fittings to route the water behind walls. Tees branch off a line to feed different parts of your house. Couplers link pipes together so you can run long lengths of pipe.
To learn about other types of pipe fittings, check out out plumbing glossary.
How do you know which pipe fitting you need?
The type of pipe fitting you need depends on what kind of pipe you're already using in your plumbing configuration. If you have a copper tubing running through your house, you need copper fittings. If you have CPVC pipe, then you need PVC fittings. If you have PEX tubing, you might need a variety of different PEX fittings or some kind of material compatible with PEX. The right pipe fitting for the job also depends on its compatibility with the fluid that runs through the application.
Is a pipe fitting measured by ID or OD?
ID stands for inner diameter. You measure the inner diameter to size NPT pipe fittings. You won't get a precise measurement if you put a ruler up to it, but it is measured by the inner diameter.
What is NPT thread size?
NPT stands for national type tapered, which means the fitting threads taper in. When you thread the fitting in, it compresses against the other threads. You need Teflon tape to thread these together and. To better understand thread sizing, please check out our article on how to determine pipe thread size and thread type.
Can pipe fittings be reused?
Yes, pipe fittings can be unscrewed and re-screwed into any other plumbing configuration, provided it has the right sealant in it like pipe dope or Teflon tape.
Learn more about fittings in these articles:
- What is a Hose Barb Fitting and How Does It Work?
- What is a Quick-Connect Fitting and How Does It Work?
- What is a Quick-Disconnect Fitting and How Does It Work?
- What is a Compression Fitting and How Does It Work?
- John Guest Quick-Connect and SharkBite fittings: Are they reliable?
Or browse our pipe fittings collection: