A flange is a method of connection pipes, valves, pumps, and other equipment to form a piping system. It is the second and most connection after welding. Flanges provides easy access for cleaning inspection or modification.
Flange Classified :
1- Flange Type
2- Flange Face
3- Size
4- Schedule
5- Pressure-temperature rating
6- Material
FLANGE TYPE :
1) Weld neck Flange:
Easy to recognize because of the long-tapered hub. It is the most widely used in process piping.
- Used for high pressure and high temperature application
- Decrease the high stress concentration at the bottom of the flange.
- Used in all pressure class
2) Slip on flange :
The flange slip over the pipe and welded with two filets welds on inside and
outside of the flange. It has short service life compared to weld neck flange.
This flange is attached to the pipe by a filled weld. The flange has a socket, so the
pipe is inserted and fits on the sockets.
- Can be used in high pressure system.
- A high skilled welder is required.
- There is an expansion gap that is must be 1/16” to prevent residual stress.
4) Threaded Flange :
It has a female thread, so it’s connected to a male thread. Unlike other flanges,
threaded flange is connected to the pipe without welding. It is used for low
temperature and low-pressure applications.
5) Lap Joint flange :
This flange consists of two parts, which are stub end and the flange. It is used for low pressure
applications.
