Do you need complete information about pipe fittings before starting your plumbing work? There are different types of pipe fittings available that are used for different purposes in plumbing work.
If you are going to do your plumbing project yourself or hire an expert to do it, you should get complete information about the various types of plumbing fittings. Some of them look the same but using the wrong type will cause severe issues.
They are available in different shapes, materials, and sizes in the market, and should be selected according to your requirement. In this article, we will study different types of pipe fittings and their uses for piping.
What are Pipe Fittings?
Pipe fittings are used to connect pipes together for different purposes. Tees or elbows are used to change the direction of the flow. To change the pipe size reducing tees or reducers are used.
Different other parts like couplings are used to stop the flow or connect, while caps are used to close flows. They are made up of different materials such as PVC, iron, brass, copper, and many more.
Piping and Plumbing Fitting Types
Tees and Sanitary Tees
Tee fitting is the easiest one to recognize. It’s called T fitting because it resembles the capital T. It makes the flow of liquid in a straight line and at a right angle from the main flow.
These fittings are useful for when a water outlet is required like when you have to add water lines in each floor of the house from the main supply of water.
In some cases, it is also used to connect two pipe pieces into one outlet. Tees are also installed in a septic tank. If these fittings are already not present in the tank, you have to add them to prevent failure of the tank.
For drain connections, a sanitary tee is used with the vertical part of the capital T positioned such that it allows the air to flow through for ventilation. The horizontal part of the tee is for the wastewater that comes from the horizontal pipe.
Often a code is required to install them. One common location of the sanitary tee is the drainage plumbing under a bathtub.
This fitting is called wye because it resembles the lowercase “y”. Its longer side works as a straight run and the shorter side is separated from it at a 45-degree angle. Usually, they are used for drainage like when you need two inlets to connect into one inlet.
Sanitary wye is used in such a way that the letter y lies on one side and the shorter angle runs upward to connect with a drainpipe. To make the vertical connection, it may be connected to an elbow.
The wastewater comes into the wye from above and also from one side, linking to a horizontal drainpipe. It is important to use wye instead of sanitary tee because the tee fitting could allow the sewer water to flow back upstream, which can create other problems.
The cross fittings are like a plus or cross sign and it also looks like a tee. It is designed in such a way that four pipes that be connected to it each at right-angle intervals from the next.
They can be used as one inlet and three outlets or one outlet and three inlets. Mostly, they are used in irrigation systems and sprinklers. For indoor applications, they are not commonly used.
In most plumbing applications, elbows are used a lot. They allow for bends because without these fittings it was impossible to do in a single piece of pipe.
Mostly they come in 45, 90, 22.5, or 60 degrees angles and are connected to the pipes where they are required. On each end, they fit the same pipe size, and if one end is reduced in size it’s called reducing elbow.
If a pipe has male or female threads at the end they can be socketed to fitted into the elbows. In most cases, street elbows has male threads at one end and female threads at the other.
Some elbows have a hub at one end but the other end is without a hub. If they don’t have any threading, they may need soldering or gluing depending on the structure.
Coupling is a type of fittings that are used to connect two pieces of pipes of the same size and material. It is made from a solid material that has a female thread on both of its sides or sometimes has no threads.
If the coupling is made of PVC and has no threads, it needs gluing for connecting. If it’s made of copper, it needs soldering.
Couplings are so useful in situations like when the size of the pipe is too short and you need to increase its height. So you add another pipe to it using coupling fittings.
They also come in handy when you have to repair a leaking pipe. Both ends of bell reducers and reducing couplings are different.
When they are installed once, they are permanently fixed and if ever a problem occurred with a pipe, you may need to cut it.
In some situations, couplings don’t work so you can use unions to attach two threaded pipes. A union has its own tightening mechanism and has a nut.
This shows that twisting the pipe into the fitting is not required; rather, the union fitting is twisted in one pipe and then the nut is slid over the other pipe. After doing so, the nut is tightened to complete the connection.
Unions come in PVC and metal materials and their ends are usually male and female. If any leakage occurs and you have to repair the connection, it is easily removable.
In some cases, you need to close one end of the pipe so a cap is useful in this situation. It is placed on the top of one end of the pipe to seal it. Some of these fittings are threaded but mostly they are not threaded.
To keep them in place, you need to glue or solder them, in this way the seal becomes permanent. Caps are made of the materials like chrome-plated brass, ABS, stainless steel, PVC, copper, and CPVC.
It is used to close one end of the pipe, like a cap. But they are different in such a way that a cap is placed over one end of the pipe while a plug is inserted into one end of the pipe like a stopper is placed at the bottle.
To insert them into the open end of the pipe, they have threads. Hence, it is also easy to remove if needed.
It is a type of fittings which has one flat part with holes and the other part with a place to fit the pipe. The purpose of the holes in the flat part is to fix them to the wall using bolts.
Although the flanges have threads in some situations, to fit the pipe into place, you need to weld it. Often, they are used to fix the toilet over the drainpipe and for domestic pump systems.
Most people use them for furniture making in industrial style. In this process, the flanges work as a holder to secure pipes, and the pipes work as legs. Flanges are made of PVC, brass, or copper.
Nipples are short pieces of fittings that have threads on both of their ends. Mostly, they are used to link two pipe fittings instead of two pieces of pipes in a straight line.
Some nipples have one closed end and have threads over that end. These fittings are made of PVC or plumbing metal.
A reducer is a fitting which is narrower from one side; its purpose is to decrease the speed of flow. There are two types of reducers; concentric and eccentric.
A concentric reducer resembles a cone with a thin opening placed on the narrow end while an eccentric reducer has a thin opening away from the midpoint slightly.
When the pipes are horizontal, the eccentric reducer decreases the air bubbles that form in the pipe. Most reducers come with threads but they have no threads in most cases.
To change the type of end on a pipe, adapters are often used from nonthreaded to threaded or from male to female. Most of the time, they have male threads at the thin end which are inserted into the pipe. Inside or female threads work as a nut.
Most people use them for copper pipes or PVC. If they are not available in the threaded form, they can be glued or soldered for fixing. Sometimes, they can be welded also.
Barbed Fittings Connections
Various plumbing fittings are available that can be used for connections depending on the type of use and material. To connect flexible plastic materials like polyethylene or PEX barbed fittings are used. Or they may be thorny at each end to accept flexible tubing at each end.
One end of these fittings has threads while the other has rings on it which are used to connect the hose. However, fastening tools are used with these barbed fittings to tighten the tubing so it does not slip away.
For hot water connection, the barbed piece is made of brass while for cold water connection, it is made of plastic. Plastic fittings can also be used for hot water links but they must be at a distance of 18 inches from the heat source.
On all kinds of fittings, barbed lines are available like tees, couplings, reducers, and elbows. These connections are not secured with glue because they are made of brass and plastic and glue is not compatible with them.
Sweat or Solder Connections
When the pipe is not threaded and you have to make a connection between metal-type set-ups, then these are connected through sweating or soldering. For example, when you have to connect a copper elbow to a copper pipe that has no threads.
As in this type of soldering very high heat is required, so using a soldering torch is better than using a soldering iron. The result of this connection is very durable and free of leaks if done properly.
It is used for the materials like copper or brass pipes. This process should be done carefully and using heat should be good to prevent accidents.
Solvent and Glue Connections
To connect two same types of plastic pipes, solvent welding creates a permanent adhesive. The solvent adhesive comprises ingredients that make the plastic and the resin soft and re-harden it with a single product, unlike traditional adhesive.
The pieces of plastic must be cut neatly and cleaned thoroughly because any debris may cause a defective connection. Whichever connector you are using, first, test-fitting the pipe then use this adhesive.
Use a brush to apply the solvent adhesive on the outer sides of the pipe and the insides of the connector. Now, place the pipe into the connector and hold them for half a minute. The connection will be made permanent.
Before starting the process, read all the directions of the adhesive to make sure that the glue works on the plastic that you are going to connect.
Threaded Pipe Connections
In most cases, threaded connections are the easiest ones because they require no soldering or gluing. They are useful for the materials like PVC and metal.
If the pipe you are using has threads, the connection you make should also be of the same material and thread. Fittings with threads are the easiest connections to remove because they need only a wrench to loosen them.
Compression Pipe Connections
A compression fitting is made of brass, plastic, or copper. It has different parts that work together to make a tight seal. Often, they are used in toilets and sinks as water shutoff valves.
This fitting has different parts like a compression nut, compression seat, and a compression ring. So, when you tighten the nut, the other parts are tightened too, in this way it makes a good seal.
These fittings slide over the pipe and push into place, so they are easy to use. In the inner side of this connector, there are stainless teeth and an O-ring that do not allow any leakage to occur.
If the pipe inside the fittings is cut neatly and there is no debris, this fitting works well. Usually, these fittings are used for water supply lines.
However, first, it’s necessary to check the codes of local plumbing because they may not be allowed in most of the places where they are hard to access. For example, the inner side of a wall without an access board.
Purpose of a Pipe Fitting
Pipe fittings have the following purposes:
- To connect two or more tubes or pipes.
- To link pieces of pipes.
- Attaching a pipe to a different device.
- To change the direction of fluid flow.
- To Regulate or maintain the flow.
- Stopping and closing a pipe.
Things to Consider Before Choosing Pipe Fittings
Consider the following things before choosing the pipe fittings:
Before buying the pipe fittings, get aware of the fact that a fitting has two different types of connectors. A fitting can have one male threaded end and one female threaded.
If the fittings are made of plastic, one end can be a male slip while the other can have threads. They also come with matching ends for different purposes.
The material of the fittings should be the same as the material of the pipes that you are going to connect. But in a few cases, materials of certain codes can be used with different material pipes.
Check for Flow
The pipe ends should be a little bigger than the rest of the pipe to keep the flow reliable. Its purpose is to have connections without narrowing the inside of the pipe’s diameter.
Type of Fitting
Pipes fittings are recognized by the type of fittings besides the materials used for example male or female, threaded or slip.
While measuring the pipe fittings’ size, keep in mind that the female thread fittings are measured to the inner diameter (ID) and the male thread fittings are measured to the outer diameter (OD).
As pipes come in different thicknesses the same is with the pipe fittings. They also come in different thicknesses.
There is a variety in pipe designs and every pipe is designed for a specific type of fluid such as gases, liquids, fluids, or chemicals under different conditions. Like pipes, pipe fittings also come in different designs.
Standard and Codes
Various organizations have set certain codes and standards which can grade different pipe fittings. Such as BSP, ASME, and ASTM are standards of some pipe fittings that show their use.
FAQs – Frequently Asked Questions
What are the Four Types of Pipe Fittings?
- Elbows: It is used to change the direction of the flow of fluid in the pipes.
- Street Elbows: One end of these elbows has female threads and the other side has male threads.
- Tee Fittings: This fitting has the shape of the capital letter “T”.
- Couplings: It is used to connect two pipe pieces of the same diameter.
What are the Common Kinds of Fittings?
These are the most commonly used fittings: Valves, flanges, elbows, outlets, reducers, adapters, unions, bushing, couplings, plugs, crosses, swage nipples, and caps.
What are Pipe Fittings and Pipe?
Pipe fittings are different parts that are used to change the direction, size, and branch connections. They are used in piping and plumbing industry extensively.
What are the Four Most Common Pipe Types?
The most common types of plumbing pipe are given below:
- Cross-linked Polyethylene (PEX)
- Polyvinyl Chloride (PVC)
- Galvanized Steel
What is the Name of the Pipe Fitting?
A union is the name of a pipe fitting that is used to connect two pipes. It has three parts; a male end, a female end, and a nut. Both ends are assembled with the help of a nut and pressure is applied to link the joint.
How Do I Recognize a Pipe Fitting?
The pipe fitting is identified by its thread. There are peaks, valleys, and spiral designs on it. And its dimensions are the amount of those threads per inch. The peak and valley have a close relationship with the dimensions.
Pipe fittings are commonly needed for all plumbing and piping system used in commercial and industrial applications. They are used for different purposes such as joining two pipes, mounting the pipe in a suitable place, or closing one end of a pipe.
There are different types of pipe fittings and they are made of different materials and have different shapes and sizes. So, you have to choose according to your requirement. Use a fitting suitable for the application; using the wrong fitting will cause problems in the plumbing system.