The types of flanges that are currently in use are as follows:

1. Socket Welded Flange (SW FLG.)

It is a flange with a hole in the (bore) as the shoulder (Socket) in connection with the pipe will be connected only to the outside only one side. The interior that is the shoulder does not need to be welded. of the weld with a radiograph method. This type of flange is commonly used with small pipes (Small Pipe) for the shoulder.SW flange It should be used as the same thickness as the pipe thickness, for example, the Sch 40 shoulder pipe of the SW flange should also be used as a SCH40.

2. Slip-on Flange (So Flg.)

SO Flange Similar to the SW flange, only the difference in the holes in the SO flange does not have an inner shoulder. Therefore, the SO flange to the pipe must be welded both outside and inside. while the SW flange is only externally welded.
This type of flange is commonly used with large pipes (Large Pipe) and is more popular than Welding Neck Flange because it is cheap and has a short neck (Hub) so it uses less distance to install.

3. Threaded Flange or Screw Flange

AreFlange with holes in the thread Suitable for use with low pressure and temperature pipe systems. Easy to assemble and install without welding, making it easy to install and can be installed in areas with flammable objects safely.

• The pipe threads that are commonly used in Thailand are BSP and NPT threads.S.K. Fitting Valve (SK Fitting Valve) can produce both standards.

4. Welding Neck Flange (WN FLG.)

It is a flange that is designed to transmit the stress (stress) that occurs with the flange. To the tube through the strong neck area, there is no problem of cracking at the welds, which can occur with Socket Welded Flange and Slip-on Flange. With this special design, this type of flange is more expensive than other types of flanges.
This type of flange is commonly used with large pipes. The assembly or installation of a butt weld method to the pipe makes it possible to check the integrity of the weld by radiograph.
The thickness of the neck of the WN flange should be used as the same thickness as the pipe thickness, such as the Sch 40 pipe.

5. Lap Joint Flange

When it comes to LAP Joint Flange, it has to be divided into 2 parts: Lap Joint Flange and Stub End Lap Joint Flange. END and then connect the stub end to the pipe by butt weld. In this way, the flange can be rotated freely from the pipe. This makes it possible to reduce the misalignment of the bolt holes and reduce the torque caused by the centrifugation of the pipes.
Lap Joint Flange and Stub End are different pieces. make an alternative to Choose materials to be more economical, for example, if the pipe material is grade 316 stainless steel, you can choose to use Stub End that is the same material as the pipe, but choose Lap Joint Flange can be carbon steel However, Galvanic Corrosion must be prevented.

6. Blind Flange

Areflange without holesopen for welding pipes Used to close the end of the system, pipe or cover the nozzles of the Pressure Vessel for various reasons such as for pressure testing (Hydro Static Pressure Test).