Guide to Plumbing Pipe Fittings

Guide to Plumbing Pipe Fittings

By: First Supply

A lot has changed in the plumbing industry since First Supply began doing business as Wisconsin Supply back in 1897. Modern plumbing fixtures and fittings are easier to find and much more reliable. The large number of fittings and accessories available allows custom solutions for even the most complex plumbing project. The drawback is that there are almost too many fittings to commit to memory. No worries. We’ve put together the following reference guide describing the different types of pipe fittings.

Adapters
Adapters

These may also be called reducing couplers or reducers. Pipe adapters are used to join two pipes of different sizes.

Barbs
Barbs

These are available in straight and curved versions. Barbs connect plumbing pipes to a hose, instead of a pipe, for hot and cold-water applications.

Bushing
Bushing

These are threaded inside and out and used to join two, different-sized pipes.

Cap
Cap

These are used to cover the end of open pipes. The kind of cap required depends on the material of the pipe being covered and whether the cap will ever need to be replaced with a coupler to extend the branch in question.

Coupling
Coupling

A coupling is a short length of pipe used to join two plumbing pipes together. There are many different couplings to fit different applications, supply lines and pipe configurations.

Cross
Cross

These are also called four-way fittings or cross-branch lines. They have a single inlet and three outlets, which allows water from a single source to flow to multiple branches in a plumbing system. Crosses are not commonly used in residential plumbing applications – they are better suited for things like sprinkler systems in case of fires in large buildings.

Elbow
Elbow

An elbow is a type of coupling that joins two pipes together, but also creates a change in direction. An elbow can be bent to varying degrees, so it’s a versatile component when designing a system.

Nipple
Nipple

These short lengths of pipe are threaded on both sides so fittings can be attached at both ends. A nipple connects two fittings, instead of two pipes.

Olet
O-let

These branch fittings provide a way to connect into the main run. These pre-shaped fittings don’t require reinforcement. Pipe O-lets are most often used for high-temperature and high-pressure applications.

Plug
Plug

Pipe plugs fit inside the end of a pipe segment to dead-end water flow. Pipe plugs provide an easy way to plug a pipe.

Reducer
Reducer

These are sometimes called reducing couplers or pipe adapters. They are used to join two pipes of different sizes.

Tee
Tee

These are couplings with two inlets instead of one. They accommodate plumbing branches that use two water sources to feed to a single place.

Union
Union

These are similar to couplings but are threaded for easy connection and disconnection. These compact flange connectors include a nut, male end and female end. The nut seals the joint by pressing the male and female ends together.

Y (Wye)
Y (Wye)

These have three openings to join or create branch lines. They allow one pipe to joined to another pipe at a 45-degree angle.

Perfect Fit

While this list is relatively short, it gives you an idea of the large number of fittings available for any plumbing job. Find a complete selection plumbing supplies, accessories and pipe fittings at First Supply.