DETAILS OF THREADED FLANGE 1. Threaded flange 2. Thread 3. Pipe or Fitting

Threaded flange is a type of flange that has taper pipe threads conforming to ASME B1.20.1 in its bore and can be used in piping systems where it is not possible to carry out welding of flange on to the pipe such as highly explosive areas where welding can create a potential hazard. The threaded flange is screwed on to a pipe which has external taper pipe threads. Most Engineering Organizations limit their use for a size range from 1/2" to 4" and for utility services such as instrument air, plant air, nitrogen, potable water and raw water up to class 300 rating.
Threaded Flanges are used for special circumstances with their main advantage being that they can be attached to the pipe without welding. Sometimes a seal weld is also used in conjunction with the threaded connection.