FLANGES - CLASSIFICATION

Classification of flanges

1. Standard flange
2. Nonstandard flange
3. Wide face flange
4. Narrow face flange

1.Standard flange

Readily for the pipe joints, connections between head and shell, etc. These can be used for moderate pressure and temperature.

2. Nonstandard flange

These are designed with specific material, shape, size, bolting arrangement, etc. as per the requirement of the process equipment. A specific design procedure needs to be followed in this case.

3. Wide face flange

Face flange. These are suitable for low-pressure operations and the temperature limited up to 200 C Since the gasket is applied all over the flange face, bolt load required for tightening the joint is very high and more bolts are required. This can become costly.

4. Narrow face flange

Not beyond the bolt hole, is called a narrow face flange. Narrow face flanges can be Classification as: spirals so that the gasket can remain in position. A flat ring gasket of soft material, slightly less in width than that of the width of the raised face is used. corresponding raised face. The flange face is smooth provided with a raised ring called a tongue. Tongue and groove construction needs a narrow flat gasket.in shape. A ring gasket fits in the grooves and is well protected.
Standard flanges are designed as per I.S. standard and are available Nonstandard flanges are formed from structural section or plate. If the gasket is applied all over the width of the flange, it is called as wide If the gasket is applied only over some part of the flange, specifically

(a) Raised face flange

In raised face flange some portion of the flange face is raised and is finished with grooves or

(b) Male and female face flange

In male and female facing one flange has a recessed face while the other flange has a

(C) Tongue and groove face flange

In tongue and groove facing one flange is provided with a groove while the other flange is

(d) Ring face flange

Ring flange face is formed by identical grooves on both the flanges. The grooves are trapezoidal