20 Types of Plumbing Fittings Explained With Pictures

For the average homeowner, knowing which plumbing fitting goes where can be a challenge. There are many different types, sizes, and materials to consider. Which ones you need depends on the job.

If you need some more guidance, you’ve come to the right place. We’ll take you through 20 of the most common types of plumbing fittings.

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Different Plumbing Fittings

1. Adapter

An adapter has male and female ends, the male having threads on the outside and the female on the inside.

They’re used to connect different sized pipes, or even turn a male pipe into a female, and vice versa.

There are three types of adapters: male, female, and straight-threaded. If one of the ends of the adapter is without threads, it needs to be welded or soldered onto the pipe.

Adapters are essential when it comes to extending or terminating pipe runs. Leak-free adapters can withstand high pressure, commonly used in gas and water pipes. They also provide a smooth transition from piping to tubing systems.

You can find adapters in a range of materials, which include:

• Steel.
• Aluminum.
• Rubber.
• Brass.
• Copper.
• Cast iron.
• Polymers.

2. Nipple

A pipe nipple is one of the most popular types of fittings; it’s also very important. It connects pipes to appliances such as water heaters, and connects two straight pipe runs.

The nipple fitting has two male ends and comes in various materials and finishes, such as:

• Brass.
• Aluminum.
• Copper.
• PVC.
• Carbon steel.
• Stainless steel.

There are five types of pipe nipples, including:

• Weld nipple: Used to connect tube fittings. They’re strong and can be used under extreme pressure surges, vibrations, and changes.
• Hexagon nipple: This has two threaded ends and a hexagonal center. Available in a variety of materials, lengths, and threads.
• Swage nipple: Used to get fluids through one pipe size to a different size.
• Barrel nipple: Short tubular nipple with an external taper thread at each end, and is un-threaded in between.
• Close nipple: Threaded throughout both ends. Also referred to as a “running nipple.”

Before buying a pipe nipple, it’s important to consider material, thickness, and diameter to make sure you get the correct fitting.

 

3. Union

Union fittings are made up of three parts: a nut, a female end, and a male end. They’re designed to connect two pipes with the possibility of being detached without damage or deformation to the pipes. They’re conveniently used in maintenance or cases of planned replacements in the future.

Pipe unions are available in a wide range of durable materials such as:

• Cast iron.
• Nickel.
• Brass.
• Bronze.
• Plastic.
• Rubber.

One of the many advantages with union fittings is that they’re easy to install.

They’re used in various industrial and municipal applications such as process piping and wastewater systems. When buying a union fitting, consider which type and size you need.

4. Barb

Barb fittings are generally male at one end and have a tapered and ridged cone at the other. They’re designed to grip the inside of a tube and seal the connection.

As the barb fitting is inserted, the hose or tube will first expand and then relax. When the tube or hose relaxes and goes back to its original size, the connection is sealed and becomes difficult to undo. Barbed fittings are generally used in gas, air, and fluid control applications in low pressure.

For water connections, plastic barbs are used for cold water. Brass barbs are used to carry hot water. Before buying a barb fitting, consider the following:

• Material compatibility.
• Single or multi-barb.
• Hardness of the tube or hose.
• Inner diameter of the hose or tube.

5. Coupling

Couplings are very similar to unions. However, these can’t be detached without damage to the pipes.

Couplings can be used to connect two pipes of the same size and diameter. They’re also commonly used to change pipe sizes; a bell reducer is a common coupling used to do this since it connects a big pipe to a smaller one.

You’ll find couplings with female threads or un-threaded. Un-threaded couplings are used for either copper soldering or plastic solvent welding.

There are two other main types of couplings:

• Compression: Connected between two pipes using gaskets or rubber seals on both ends. The seals prevent leaking.
• Slip: Usually used to repair a certain length of damaged pipe.

Coupling fittings are available in a range of materials; these include:

• ABS.
• Chrome-plated brass.
• Brass.
• CPVC (chlorinated polyvinyl chloride).
• PVC.
• Stainless steel.

6. Cross

As the name might suggest, crosses are four-way fittings, a combination of two tees (see below). They consist of one inlet and three outlets, and these often have a solvent-welded socket or female-threaded ends.

Cross fittings aren’t as popular as tees. The reason being that they can stress pipes as temperature changes due to the four open ways.

Crosses are mostly used in plumbings where thermal expansion isn’t an issue, such as fire sprinkler systems.

These types of fittings are available in the following materials:

• Brass.
• Steel.
• Stainless steel.
• Malleable.
• PVC.

7. Tees

Tees are a three-way fitting. They look like a coupling with an outlet in the middle. They’re short pipes with a 90-degree “branch” at the center.

There are two main types of tees:

• Straight tee: Used in setups where the pipe run is the same size as the tee branch.
• Reducing tee: Used where the tee branch is smaller than the run pipe.

Tees are available in a range of materials:

• ABS.
• Chrome-plated brass.
• Brass.
• Copper.
• CPVC.
• PVC.
• Stainless steel.

8. Saddle Tee

Saddle tees look very similar to a real saddle. They’re only available in PVC and used to add a tee to an existing pipe without the need to cut or re-solder.

These are most often used in irrigation systems when you need to add a new sprinkler line. Saddle tees are “snapped” onto the pipe using glue. Once the glue is settled, a new hole is drilled.

9. Wyes

Wyes look like the letter “Y.” They’re generally used in drainage fittings and have a 45-degree branch.

The angling of the branch is designed to reduce turbulence and friction. They connect vertical drain pipes to horizontal ones.

Wye fittings are available in:

• ABS.
• PVC.
• Brass.

10. Flanges

A flange is a round fitting used to connect pipes. The pipes are either threaded or welded to the middle of the flange, and then sealed together. The holes on the outside are used for bolts.

Flanges are mainly used in industrial applications due to their ability to handle high pressure. You can also find flanges in residential pump systems.

At home, PVC flanges are used when mounting toilets to the floor. These are also referred to as “closet” flanges.

They’re offered in several materials:

• Copper.
• Malleable.
• PVC.
• Brass.

11. Elbows

Elbow fittings are curved and are mainly used to change flow directions. These are mostly produced in 45 and 90-degree angles and can be sweated or threaded.

The ends of the elbow fitting can be made for butt welding, threading or socketed. A reducing elbow is when the two ends differ in size.

Elbows are made in these different materials:

• Brass.
• Chrome-plated brass.
• CPVC.
• Copper.
• ABS.
• PVC.
• Stainless steel.

12. Caps

Caps are used to cover the end of an open pipe and are liquid- and gas-tight. The cap can be attached to the pipe end by interior threading (female), or solvent-welded socket.

The outside of a cap can be square, round, rectangular, I- or U-shaped; some will even have a handgrip.

Caps are available in a range of materials:

• ABS.
• Copper.
• CPVC.
• Brass.
• Chrome-plated brass.
• PVC.
• Malleable.
• Stainless steel.

13. Plugs

Plugs are used similarly to caps, but instead of being fitted on the pipe, they’re fitted inside. These are usually threaded to allow the plug to be removed for future use of the pipe.

These are offered in many of the same materials as caps:

• ABS.
• Copper.
• Brass.
• Stainless steel.

14. Bushings

Bushings look like small screws. They’re mainly used to connect pipes of different sizes, reducing a large fitting to a small pipe. These can be threaded on the inside and outside; however, this is not always the case.

Bushing fittings are smaller than unions and couplings, and are, therefore, often used in the same situations.

This type of fitting is available in:

• Brass.
• Chrome-plated brass.
• CPVC.
• Copper.
• ABS.
• PVC.
• Malleable.

15. Mechanical Sleeve

A mechanical sleeve joins two pipes using a screw or other device and is easy to install.

The sleeve is usually made of rubber and is inserted into a stainless steel clamp. The clamp compresses the rubber, which creates a tight seal.

This type of fitting is slightly flexible and can be used in misalignments in difficult places.

16. Valve

A valve is used to regulate or stop the flow of gas or liquid. Valves are generally categorized by application, such as:

• Isolation: Used to disconnect a part of a piping system temporarily. Usually left fully open or closed, and can be in place for years before replacement.
• Throttling: Used to control the pressure of a fluid. Designed to withstand wear and stress; however, they might eventually give in. Usually installed along with an isolation valve in case of malfunction.
• Non-return: Also called check valves, these allow a free flow of fluids in one direction, but prevents reverse flow. Often used in sewage and drainage systems.

Valves are mainly made of metals such as:

• Bronze.
• Cast iron.
• Cast steel.
• Stainless steel.
• Carbon steel is used for high pressure or high temperatures.

17. Reducer

A reducer is designed to reduce flow. It comes in two types:

• Concentric reducer: Looks similar to a cone. Designed to join two pipe sections on the same axis. Usually used when there’s a change in pipe diameter.
• Eccentric reducer: Used in piping systems where the upstream pipe is larger than the downstream pipe.

Reducers are available in a range of materials such as:

• Carbon steel.
• Alloy.
• Stainless steel.

18. Clean-Outs

A clean-out fitting features removable parts that allow access to drains without the need to undo plumbing fixtures. Clean-outs will enable an auger (a type of drill) to enter and clean a clogged drain.

Its crucial clean-outs are placed in accessible locations since an auger isn’t the longest tool. Larger plumbing systems feature several clean-outs that will be placed at regular intervals.

Clean-outs are mostly made out of PVC.

19. Combo Tee

Combination tees have a gradually curving central branch. They’re used in drains to give a smooth, slightly curving path to reduce the chances of clogs. The curve also makes it easier for a plumber to push a snake tool through.

These fittings are available in PVC material.

20. Diverter Tee

This type of tee is mainly used in pressurized hydronic heating systems. It diverts portions of the flow from the primary line into a side branch that’s connected to a heat exchanger.

It’s designed to allow a regular flow through the main line, even if the branch is shut off.

Installing a diverter tee can be a challenge. It features directional marking that must be followed. If it’s installed backward, it won’t function properly.

Diverter tees are available in materials similar to regular tees:

• Stainless steel.
• ABS.
• Brass.
• Chrome-plated brass.
• Copper.
• PVC.

Types of Plumbing Fittings FAQs

Types of Piping Systems

“Newer” homes across the United States (built in the mid-1970s) are fitted with plastic pipes and fittings. The materials used are rated by the American Society for Testing and Materials.

This rating system can be used for pressurized fixtures like cold and hot water distributions, potable water and irrigation systems. It can also be used for non-pressurized installations like drainage, sewage, and storm drain systems.

Older homes (before 1960) used cast iron or galvanized steel pipes for their drain, waste and vent systems (DWV). DWV systems are designed to remove wastewater while preventing the flow of sewer gasses from entering homes.

Today, homes are fitted with PVC (polyvinyl chloride) and copper pipes. These materials are sturdy, long-lasting, and most importantly, easy to install ⁽²⁾.

Plumbing Fittings Material Guide

Using the right material can mean the difference between worry-free and leak-filled. Knowing which materials go where can help you to find the right fittings for your home quickly.

• Cast-iron fittings: Can go in DWV systems and are usually black.
• PVC schedule 40: Used in DWV systems, irrigation, and outdoor applications such as pools and sprinklers. The material can be used in pressurized systems as well. It can’t be used for compressed gasses or air.
• PVC schedule 80: Can be usedin pressurized systems. It can be used for pressurized liquids, but not gasses or air.
• Copper: Used for hot and cold water distributions in pressurized systems.
• Acrylonitrile butadiene styrene (ABS): Commonly used in DWV systems in western parts of the US.
• Brass: A mixture of metal alloys such as copper and zinc, brass is a common material for fittings. It’s used in pressurized systems, mostly for potable water and in hot water applications ⁽³⁾.
• CPVC (chlorinated polyvinyl chloride): Commonly used for drinking water at higher temperatures (up to 200 degrees). It can withstand higher temperatures compared to PVC ⁽⁴⁾.

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Fit Fittings

Pipes can be easy to shop for — all you need to know is the length and material. However, fittings are a completely different story. It’s crucial you use the correct fittings for the different areas.

The material also plays an essential role since the wrong choice could lead to leaks or malfunctions within your system. By following our types of plumbing fittings guide, you should be feeling a little more confident next time you’re on the hunt for plumbing fittings.

Do you do your plumbing at home? Which type of fitting do you prefer to use? Let us know in the comments section below.