What is a weld neck flange
A weld neck flange has two designs. The regular type is used with pipes. The long type is unsuitable for pipes and is used in process plant.A weld neck flange consists of a circular fitting with a protruding rim around the circumference. Generally machined from a forging, these flanges are typically butt welded to a pipe. The rim has a series of drilled holes that permit the flange to be affixed to another flange with bolts.Such flanges are suitable for use in hostile environments that have extremes of temperature, pressure or other sources of stress.The resilience of this type of flange is achieved by sharing the environmental stress with the pipe with which it is welded.
Specification of weld neck flange
|Shape Type||Regular and Long Neck|
|America Standard||ASME B 16.5/ASME B 16.47 SERIES a/b|
|Carbon Steel||ASTM A150/A150N|
|Low Tem Carbon Steel||ASTM A350 LF2/LF3|
|Pipeline Steel||ASTM A694 F42/46/56/60/65|
|Alloy Steel||ASTM A182 F11/F12/F5/F9/F91/F92|
|Stinless Steel||ASTM A182 F304/304L/304H,316,316L,310S,317,347,904L|
Advantages of weld neck flange
Because long weld neck flanges are bored to match the inside diameter of the pipe itself, the flow of high-pressure liquid is not impeded. This design assures that there is little “turbulence” within the pipe, a common cause of erosion, resulting in stronger more durable pressure vessel connections.