Necked flange neck height is lower, the stiffness of the flange, bearing capacity has improved. Compared with the butt-welding flange, welding workload, welding rod consumption is high, can not withstand high temperature and high pressure and repeated bending and temperature fluctuations, but the site installation is more convenient, can omit the weld beat the process of rubbing injury, more popular. Neck butt welding butt welding flange: neck flange welding is usually called “high pivot” flange.

　　Its purpose is to transfer the pressure of the pipeline, thus reducing the high stress concentration at the base of the flange. Neck flange welding is good for those flanges that are designed to provide butt welding due to its own constructive value of existence. However, the price is relatively high, due to the complexity of the product's consumption process. Threaded (threaded) flange: This threaded flange is connected with a silk buckle. But the center of the product has a thread size corresponding to the pipe. Its main advantage is that it can be assembled without welding.

　　Sliding flange: The sliding flange has a lower pivot due to the pipe into the monoflange before welding. This is welded internally and externally to provide sufficient strength to avoid leakage. Sliding flanges are boring to match the slightly larger outside diameter of the pipe. They are superior to neck flanges for welding due to the lower initial cost.

　　Many users, but after the installation costs are about not lower due to the increased weld neck flange less, lap flanges: In practice the lap flanges are identical to the sliding flanges, unless it is a radius between the hole and the flange race. This is the necessary radius to have a flange inclusive of the lap stub finish. Usually, the lap flange and lap stub end mating together will be assembled system.

　　The socket weld flange is a similar sliding flange unless it has a hole and counterbore dimension. The counter bore matches the pipe so that the pipe is inserted into the flange similar to a sliding flange. The diameter of the hole in the smaller hole is the same as the ID of the same pipe match. The restriction is built into the hole, as a shoulder sleeve designed for the pipe stays on the bottom. This eliminates any flow restriction in the utilization of socket weld flanges.