Long Welding Neck Flanges are easy to recognize. They include a long tapered hub that gradually meets the wall thickness from the pipe or fitting. The long tapered hub provides an important reinforcement for use in several applications involving high pressure, sub-zero and / or elevated temperatures. In conditions of repeated bending, caused by line expansion or other variable forces, the smooth transition from flange thickness to pipe or fitting wall thickness is extremely beneficial. These flanges are bored to match the inside diameter of the mating pipe or fitting so there will be no restriction of product flow. This prevents turbulence at the joint and reduces erosion.