21 Types of Plumbing Fittings (With Photos)

Staring at a wall of copper, PVC, and brass parts at the hardware store is enough to make your eyes glaze over. A street elbow, a diverter tee, a barb: the names alone can sound like another language.

Here is the reassuring part. Almost every plumbing fitting does one of three simple jobs. It joins two pipes, changes the direction of the flow, or adapts one size or material to another. Once you see them that way, those bins start to make sense.

This guide walks through 21 plumbing fittings you will meet on real DIY projects, what each one does, which material to reach for, and how to choose the right part so you do not end up mopping the floor.

Types of Plumbing Fittings

1. Adapter

Adapters are the problem solvers of plumbing. They feature “male” (threaded on the outside) and “female” (threaded on the inside) ends to connect incompatible pipes.

You generally use these to connect pipes of different types or sizes. For example, if you need to turn a male pipe end into a female connection, you grab an adapter.

There are three main types of adapters: male, female, and straight-threaded. If an adapter has no threads, it is usually designed to be soldered (sweated) or glued (solvent welded) directly onto a pipe.

Adapters are essential for:

• Extending pipe runs.
• Terminating a line.
• Transitioning between piping and flexible tubing.

You can find adapters in a variety of materials, including:

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

2. Nipple

A nipple is essentially a short piece of pipe with male threads at both ends. It is one of the most common fittings you will see, often used to connect two female fittings or attach pipes to appliances like water heaters.

These fittings come in various materials to match your system:

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

There are five specific types of pipe nipples you should know:

• Weld nipple: Designed for heavy-duty use; connects tube fittings and handles extreme pressure or vibration.
• Hexagon nipple: Features a hexagonal center section, making it easy to tighten with a wrench.
• Swage nipple: Used to transfer fluids from one pipe size to a different size.
• Barrel nipple: A short tube tapered at both ends but un-threaded in the middle.
• Close nipple: Threaded from end to end with no bare pipe in the middle. These are also called “running nipples.”

3. Union

A union connects two pipes, but unlike a standard coupling, it is designed to be taken apart.

Unions consist of three parts: a nut, a female end, and a male end. Once installed, you can unscrew the large nut to separate the pipes without having to cut the pipe or destroy the fitting. This makes them perfect for installing equipment that might need maintenance or replacement later, like pumps or heaters.

Common materials for unions include:

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

4. Barb

Barb fittings are used to connect flexible tubing or hoses to pipes. They usually feature a male thread on one end and a tapered, ridged cone (the barb) on the other.

The ridges allow the tube to slide on but prevent it from sliding off. When used with a hose clamp, they create a tight, sealed connection. You will often see these in low-pressure applications, such as gas lines, air hoses, or garden irrigation.

Material matters here:

• Plastic barbs: Best for cold water connections.
• Brass barbs: Better for hot water or gas.

5. Coupling

Couplings are the simplest way to join two straight pieces of pipe. Unlike unions, couplings are permanent; you cannot separate the pipes later without cutting them.

They typically connect two pipes of the same size. However, “reducing couplings” (or bell reducers) exist to join a larger pipe to a smaller one.

There are two distinct types of couplings to look for:

• Compression: These use rubber seals or gaskets and a tightening nut to prevent leaks. No glue or solder is required.
• Slip: One piece slides into the other. These are usually commonly used to repair a damaged section of pipe.

Couplings come in all standard materials, including:

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

6. Cross

Crosses are four-way fittings that look like a “plus” sign. They have one inlet and three outlets (or vice versa).

While they seem useful, cross fittings are rare in standard home plumbing. Because four pipes meet at a single point, temperature changes can cause significant stress on the fitting.

You mostly see these in fire sprinkler systems or irrigation setups where thermal expansion is not a major concern.

Cross fittings are available in:

• Brass
• Steel
• Stainless steel
• Malleable iron
• PVC

7. Tees

Tees are the workhorses of plumbing. Shaped like the letter “T,” they have one inlet and two outlets at 90-degree angles. They are used to split a line or combine two lines into one.

There are two main configurations:

• Straight tee: All three openings are the same size.
• Reducing tee: The side outlet (the branch) is smaller than the main line, which helps maintain pressure when branching off to a fixture.

8. Saddle Tee

Saddle tees are a DIY favorite for adding a line to an existing pipe without cutting it. They snap over the pipe like a saddle on a horse.

You glue or bolt the saddle onto the pipe, and once it is secure, you drill a hole through the fitting’s opening into the original pipe. These are extremely common in irrigation systems for adding sprinklers but are rarely code-compliant for indoor water supply lines.

9. Wyes

Wyes look like the letter “Y.” While tees split water at 90 degrees, wyes have a 45-degree branch.

This angle matters for drainage and wastewater systems. The smoother 45-degree angle reduces friction and turbulence, helping waste flow smoothly without clogging. You typically use these to connect a vertical drain pipe to a horizontal one.

Wye fittings are available in drainage-specific materials like:

• ABS
• PVC
• Brass

10. Flanges

A flange is a flat, round fitting used to create a tight seal between two surfaces using bolts.

In residential homes, the most common flange you will encounter is the “closet” flange (toilet flange). This secures the toilet to the floor and connects the toilet drain to the home’s waste pipe.

In industrial settings, heavy-duty flanges connect large sections of pipe to withstand high pressure.

11. Elbows (Ells)

Elbow fittings change the direction of the flow. Without them, you would have to bend the pipe itself, which isn’t always possible.

The most common angles are 90 degrees (a sharp corner) and 45 degrees (a softer turn). You can also find “street elbows,” which have one female end and one male end, allowing them to plug directly into another fitting without needing a connecting nipple.

Elbows also come in long-radius and short-radius versions. A long-radius elbow curves more gently, with a radius of curvature about 1.5 times the pipe diameter, so water flows through with less turbulence. A short-radius elbow makes a tighter turn in the same footprint, which helps when space is cramped. The elbow is the single most-used fitting in any plumbing system.

Elbows are made from every standard plumbing material:

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

12. Caps

Caps go over the end of a pipe to seal it shut. They are liquid and gas-tight.

You use caps to terminate a pipe line or to temporarily seal a pipe during a renovation project. They can be glued, soldered, or threaded onto the pipe end.

13. Plugs

Plugs do the same job as caps, but they go inside the fitting rather than over the pipe.

Plugs typically have a threaded head, allowing you to screw them into a fitting to close it off. Because they are threaded, they are excellent for clean-out ports where you might need to open the pipe later to remove a clog.

14. Bushings

Bushings are technically a type of adapter or reducer, but they are very compact. They look like a small screw or cylinder that fits entirely inside another fitting.

You use a bushing to connect a smaller pipe into a larger fitting. For example, if you have a 1-inch fitting but need to connect a 1/2-inch pipe, a bushing screws inside the larger hole to reduce the size.

15. Mechanical Sleeve

Also known as a rubber coupling or a “Fernco,” a mechanical sleeve connects two pipes using a rubber cylinder and stainless steel clamps.

These are a go-to for repair jobs. If you have two pipes that are slightly misaligned or made of different materials (like connecting old cast iron to new PVC), a mechanical sleeve flexes to make the connection. You tighten the clamps with a screwdriver to create a water-tight seal.

16. Valve

Valves are not just fittings; they are controls. They regulate or stop the flow of water.

Common types include:

• Ball Valves (Isolation): The most reliable shut-off valve. A lever turns a ball inside to stop flow completely.
• Gate Valves: An older style where a “gate” screws down to stop water. These are prone to failing over time.
• Check Valves (Non-return): These allow water to flow only one way. They are important in sump pumps and drainage to stop dirty water from coming back in.

17. Reducer

A reducer connects a larger pipe to a smaller one to change the flow rate.

• Concentric reducer: Cone-shaped; keeps the pipes centered on the same axis.
• Eccentric reducer: Keeps one side of the pipe flat/level, which is useful in horizontal runs to prevent air pockets from forming.

18. Clean-Outs

A clean-out is an access point for your drain lines. It consists of a pipe fitting with a removable threaded plug.

If your main sewer line clogs, you unscrew the plug on the clean-out and feed in an auger (snake) to clear the blockage. You should never permanently seal a clean-out; always use a threaded plug.

19. Combo Tee

A combination tee (or “combo”) blends a standard tee and a wye. It has a curving central branch rather than a sharp 90-degree angle.

These are used in drain systems to help waste flow smoothly around a corner while also providing an opening for a clean-out or vent. The gradual curve makes it much easier to push a plumbing snake through compared to a standard tee.

20. Diverter Tee

These are specialized fittings used primarily in hydronic (hot water) heating systems.

A diverter tee forces a portion of the hot water into a side loop (like a radiator) while allowing the rest to continue down the main line. They must be installed in the correct direction; if you put them in backward, your heating system won’t work efficiently.

21. Push-to-Connect (SharkBite)

For DIYers, push-to-connect fittings take most of the guesswork out of a repair. They use internal stainless steel teeth and an O-ring to grip the pipe and create a seal the moment you push it in.

You simply push the pipe into the fitting until it clicks. No glue, solder, or clamps are required. They work on copper, PEX, and CPVC, which makes them handy for quick repairs or for transitioning between different pipe materials.

One common worry is whether you can bury them in a wall. Approved push-to-connect fittings are IAPMO-listed and meet the UPC and IPC for use underground and behind the wall as finished joints, with no access panel required. Pressure test the line first, then close up the wall with confidence.

Plumbing Fittings Material Guide

Choosing the right material matters. If you connect two dissimilar metals, like copper and galvanized steel, the water between them acts as an electrolyte and drives galvanic corrosion, which eats at the joint and leads to leaks.

When you have to join copper to galvanized or steel pipe, put a dielectric union (or a brass fitting) between them. Most plumbing codes require it because the plastic liner breaks the electrical path the corrosion needs, and a bad connection in aggressive water can start leaking in just a couple of years.

• Copper: The gold standard for water supply lines. It resists corrosion and tolerates heat well.
• PVC (White): Used for drains, waste, and vents (DWV). It handles cold water but creates toxic fumes if melted, so never use it for hot water lines.
• CPVC (Cream/Yellow): A chemically treated version of PVC that can handle hot water (up to 200°F). Useful for supply lines.
• PEX (Flexible Plastic): The modern standard for new homes. It is flexible, freeze-resistant, and easy to install.
• Brass: Durable and heat resistant. Brass works well for valves and fittings connecting to copper or iron pipes.
• Cast Iron: Found in older homes for heavy-duty drainage. It is incredibly quiet but heavy and difficult to cut.

FAQs

Where Can You Buy Plumbing Fittings?

You can buy plumbing fittings at almost any hardware store. Big-box chains like Home Depot, Lowe’s, or Ace Hardware. For specialized parts or bulk orders, online retailers like Amazon and SupplyHouse.com often have better inventory.

How Do You Measure a Pipe Fitting?

Measure a pipe fitting by its Nominal Pipe Size (NPS), which roughly correlates to the inside diameter (ID) of the pipe, not the outside. For example, a “1/2-inch copper pipe” actually measures 5/8 inch on the outside. Always measure the interior of the fitting or read the stamp printed on the side of the pipe to ensure you buy the right size.

How Do I Identify the Connection Type?

Identify a fitting connection type by looking at its ends. If it has threads (ridges) on the inside, it is a Female Thread (FIP). If it has ridges on the outside, it is a Male Thread (MIP). If it is smooth, it is a Slip fitting meant for glue or solder. If it has a ridged cone, it is a Barb for hoses. Finally, if it has a movable ring and plastic insert, it is likely a Push-to-Connect fitting.

What Is the Difference Between a Valve and a Fitting?

A valve is technically a type of fitting, but the two do different jobs. A standard fitting (like an elbow or tee) is passive; it just directs water. A valve is active; it has moving parts that allow you to control, throttle, or stop the flow of water entirely.

Do I Need Teflon Tape for All Fittings?

No, not all of them. You only need Teflon tape (plumber’s tape) or pipe dope for threaded connections (MIP/FIP). The tape lubricates the threads and fills gaps to prevent leaks. Do not use tape on compression fittings, flare fittings, or rubber seals, as the tape can actually prevent a proper seal from forming.

Can I Mix PVC and Copper Fittings?

You can mix PVC and copper, but never by gluing them straight together. To join the two, use a transition adapter. A threaded male PVC adapter screwed into a brass or copper female adapter is a common method. Alternatively, a “Fernco” rubber coupling or a push-to-connect fitting (like SharkBite) is the easiest way to bridge the two materials safely.

What Is NPT Thread Size?

NPT stands for “National Pipe Taper.” It is the standard US thread type for plumbing. The threads are tapered (they get slightly wider at the back), which forces them to bind tightly together as you screw them in, creating a water-tight seal. That is different from NPS (National Pipe Straight) threads, which keep the same diameter and do not seal on their own. A straight-thread fitting relies on an O-ring, gasket, or washer for the seal, while an NPT joint is sealed with PTFE tape or pipe dope on the threads.

What Do MIP and FIP Mean?

MIP stands for “Male Iron Pipe” (threads on the outside). FIP stands for “Female Iron Pipe” (threads on the inside). Despite the word “Iron,” the terms describe the thread on brass, PVC, and copper fittings too, not just iron. If you have a MIP pipe, you need a FIP fitting to connect to it.

Can You Use Push-to-Connect Fittings Behind a Wall?

Yes, approved push-to-connect fittings can go behind a wall or underground. Major brands are IAPMO-listed and meet the UPC and IPC for use as finished joints with no access panel, so you do not have to leave them exposed. Pressure test the line to confirm there are no leaks, then seal up the wall.