Plumbing fittings connect pipes of different sizes and materials together. They’re a crucial part of any plumber’s toolbox.
They’re sized to match the pipe and come in all kinds of shapes, like elbows, reducers and tees. And they’re made from a variety of materials, from copper to CPVC and ABS.
Couplings
A coupling is a device that connects two shafts to transport power precisely. They are used in virtually every industrial machine that requires power transmission.
Couplings also help to absorb misalignment and prevent damage to driven components. This is especially important in machinery where the motor is often moving slightly, as well as in applications where the drive is under emergency braking or stopping conditions.
Rigid couplings are rigidly fixed to the ends of the shafts they are connecting. The simplest of these is the sleeve or muff coupling, which consists of a cast-iron cylinder with an inner dia that matches the external diameter of the shafts being connected to it.
The muff is fixed over the end of each shaft with a gib head key. This allows the power transmission between the two shafts to take place through the muff, the key and a shaft that has been threaded through the muff. This type of coupling is most commonly found in low- and medium-duty torque applications.
Unions
Usually, unions are used for small diameter piping connections that require positive seal and easy assembly and disassembly. They are also used in swimming pools.
These fittings are usually made up of three parts, including a male and female end and a nut. The nut provides the necessary pressure to seal the connection when both the ends are brought together.
In some cases, a Teflon tape can be put between the threads of the connecting pipe and the union thread to prevent leakage from leaking through the threaded connection. However, a proper gasket or rubber seal is required to maintain water tightness between the union and connecting pipe.
There are two main types of unions; ground joint union and flange union. The former is made up of an angle that cuts into the joint to increase its surface area, thereby helping in seating properly. The latter is made up of two pieces that are screwed on to the ends of the pipes and welded or bolted to hold them together.
Tees
Plumbing fittings are the parts that connect pipes together and help in changing the flow or size of the pipe. They can also be used to connect different components in a piping system without leakage.
Tees are some of the best plumbing fittings for their purpose, as they can combine and divide fluid flow or change the direction of a pipe run. They are available in various materials, sizes and finishes.
They can be used to transition pipes from one material to another, such as from PVC to copper or vice versa. They can also be used to make a connection between two different types of tubes, such as a steel pipe to a plastic tube or a copper tube to a brass tube.
They can be found in a variety of sizes and are commonly made from CPVC, brass or galvanized. They can be crimped or threaded for different applications. Some are made of stainless steel.
Elbows
Pipe elbows are a very important part of pressure piping systems. They are used to connect two pipes with the same nominal diameter and to change the direction of the fluid flow (usually to 45 degrees or 90 degrees) within the system.
They are available in short and long radius, and can be used for various applications. However, the best choice depends on three main parameters: space availability, cost and pressure drop.
There are a variety of different types of elbows to choose from, and each one has a different purpose. The most common elbow is a 90 degree bend, but there are 45-degree and 22-1/2-degree bends as well.