What is Pipe Fittings?
Pipe Fittings are Piping component which helps in Changes the direction of the flow such as elbows, tee. Changes the size of the pipe such as reducers, reducing tees. Connect to components together such as couplings and stop the flows such as Caps.
Types of Pipe Fittings Used in Process Piping.
The Elbow is used more than any other pipe fittings. It Provides flexibility to change the pipe direction. Elbow mainly available in two standard types 90° and 45°. However, it Can be cut to any other degree.
Long Radius Vs Short Radius Elbow
Elbows are available in two radius types, Short radius (1D) and Long radius (1.5D).
A Long Radius elbow is having the radius equivalent to 1.5 times the Diameter of the pipe and a Short Radius elbow is having the radius equivalent to the Diameter of the pipe.
- LongRadius A=1.5D
- Short Radius A=1D
When fluids are transported to long distances or go frequent directional changes, short radius elbows are not recommended because of their greater friction loss, which may require the installation of larger pump or compressor.
The 90 reducing elbow is designed to change direction as well as reduce the length of flow within a piping system. The reducing elbow eliminates one pipe fitting and reduces the welding by more than one-third. Also, the gradual reduction in diameter throughout the arc of the reducing elbow provides lower resistance to flow and reduces the effect of stream turbulence and potential internal erosion. These features prevent sizeable pressure drops in the line.
Miter bends are not standard pipe fittings they are fabricated from pipes. Usually, they are preferred for size 10” & above because large size elbow is expensive. Use of miter bend is restricted to low pressure water line. Miter bend can be fabricated in 2, 3, & 5 pieces.
Retuning elbows are used to make an 180º change in direction. Available in short & long pattern. Mainly used in the heating coil, heat exchanger etc.
There are different types of Tee used in piping,
- Equal/Straight Tee– in this type of tee Diameter of Branch is same as the Diameter of the Run Pipe
- In Reducing Tee – Diameter of the Branch size is smaller than the Diameter of the Run Pipe
Cross are also known as four-way pipe fittings. A cross has one inlet and three outlets (or vice versa). Generally, crosses are not used in process piping to transport fluid. But forged crosses are common in the fire water sprinkler line.
There are two types of reducer used in piping Concentric & Eccentric.
Offset = ( Larger ID - Smaller ID) / 2
- In Concentric reducer, the center of the both the ends is on the same axis. It maintains the centerline elevation of the pipeline.
- Whereas in the Eccentric reducer, the center of the both the ends is on different axis as shown in the image. It maintains BOP (bottom of pipe) elevation of the pipeline.
The swage is like reducers used to connect butt welded pipes to smaller screwed or socket welded pipes. Like reducers, they are a concentric & eccentric type.
Pipe caps are used at the dead end of the piping system. It is also used in piping headers for future connections.
Stub ends are used with lap joint flange. In this type of flange, the stub is butt welded to a pipe, whereas flange is freely moved over the stub end.
Union is used to connect small bore pipes. It can be socket end or threaded end.
Half Coupling & Full Coupling:
Half Coupling generally used for branching or for vessel connections. It can be threaded or socket type.
Full Coupling Generally used for connecting pipes or items with either threaded or socket ends.