Weld Neck Pipe Flanges

Weld neck pipe flanges are attached to the pipe by welding the pipe to the neck of the pipe flange. Used in conjunction with a "Lap joint Stub End", these flanges are nearly identical to a slip-on flange with the exception of a radius at the intersection of the flange face and the bore to accommodate the flanged portion of the stubbed. 
This group of flanges is designed with a hub on the backside tapering to a diameter that will match the pipe to which it will be welded. These flanges are bored to match the inside diameter of the mating pipe so there will be no restriction of product flow. This allows for the transfer of stress from the weld neck pipe flanges to the pipe itself and also reduces high stress concentration at the base of the hub of the weld neck pipe flanges. 
These flanges are often used for high pressure applications. To match the inside diameter of the pipe, the inside diameter of a weld neck pipe flange is machined. Weld Neck Pipe flanges with a hub have published specifications that range from 1/2" thru 96". Simplex Trading Company provides Weld Neck pipe flanges in all material grades, specifications and sizes.