Piping Fittings: Components

Apart from pipe, different piping fittings components are used in a piping system.

Each component has a different function and location in the piping system as per the requirement.

Different Piping components are discussed below:

1. Elbow
2. Tee
3. Reducer
4. Couplings
5. Swage nipples

1. Elbow:

It is a component used in piping fittings to change the direction of a pipe run by 90 Deg or 45 Deg.

As per the end connection they are available as Butt welded and Socket welded type.

Butt welded are categorized as:

Long radius -Radius 1.5 D (‘D’=Nominal Pipe size)

Short radius- Radius 1 D (‘D’=Nominal Pipe size)

Any bends which is having radius more than 1.5D has to be specially fabricated.

Long radius elbow R-1.5D

Elbow-45

2. Tee:

It is a component used in piping fittings to take a branch off from the main pipe run. As per the end connection they are available as Butt welded and Socket welded type.In case of Low pressure services the branching off is done by directly pipe to pipe welding. This is called as Stub-in or Stub-on connection. Depending on the size and the thickness of the branch-off sometime times reinforcement pads are welded on the main pad for the area compensation purpose.

The requirement of the reinforcement pad is specified in the code ASME B31.3. The branch table or schedule are generally is a part of each piping specification which gives the type of fitting to be used depending on the size of header and corresponding size of the branch.

As a general rule the availability of the reducing Tee sizes can be known by dividing the main pipe size by 2 and consider the next lower size. But the actually availability should be checked and confirmed with the standards.

3. Reducer:

It is a component used to reduce the size of main pipe run to a smaller pipe run.

They are available only as Butt welded type.There two type of reducers available:

1) Concentric Reducer:

Used to maintain the centerline of the main pipe run.

2) Eccentric Reducer:

Used to maintain the back of pipe or bottom of pipe of the main pipe run. The general rule for the availability of reducer sizes is same as Tee.

Pipe concentric reducer

Pipe eccentric reducer

4. Couplings: 

There are three types of coupling available each type is used in the piping system depending upon the requirement

Full coupling:

Used to join small bore plain end pipes where the pipe spec requirement is socket weld

Half coupling:

Used to take a small bore pipe branch-off from a large bore pipe where the pipe spec requirement is socket weld in small bore size

Reducing coupling:

Used to reduce the size of a small bore pipe maintaining the centerline of the pipe.

Pipe full coupling

Pipe half coupling

5. Swage Nipples: 

The function of Swage nipples are the same as reducer the only difference is that they are generally used to connect butt welded pipe to a socket welded or screwed pipe.

There are also available as Concentric and Eccentric type.

The different end connections available are:

PBE-Plain Both Ends

PLE-Plain Large Ends

PSE-Plain Small End

BLE-Beveled Large End

TSE-Threaded Small End

Pipe concentric swage nipples

Pipe eccentric swage nipples