Flange is a common part in piping system. They are mainly used to connect shafts and shafts or to connect two devices. In general, flanges are used with gaskets and bolts. The purpose is to fix two pipes, pipe fittings or equipment on the flange, then add flange gasket between the two flanges, and then use bolts to tighten the two flanges to make it tight connection. Therefore, it is also a common connection method in pipeline system.
Ensure that the sealing surface is clean and free from defects
- (1) The center of the flange must be in line with the center of the pipe.
- (2) The flange sealing surface must be perpendicular to the piping center.
- (3) The position of flange threaded hole on the pipeline shall be consistent with that on the opposite equipment or pipeline, and the position of flange threaded hole on both ends of the same pipeline shall be consistent.
Installation of flat welding flange
Installation of weld neck flange
Weld neck flange this kind of pipe fittings refers to the flange with neck and round pipe transition and butt welding connection with the pipe. Different from flat welding flange, weld neck flange is not easy to deform and has good sealing performance. In addition, they are relatively cheap, so they are widely used. Weld neck flange is suitable for pipes with large fluctuation of pressure or temperature or high temperature, high pressure and low temperature pipes. It is used to transport precious, flammable and explosive media. So, do you know how to install and use weld neck flange? When installing and using weld neck flange, we should know the precautions?
- 1. Before installing the weld neck flange, pay attention to check whether the nominal pressure of the flange meets the design requirements; check whether the sealing surface of the flange is smooth and clean, whether there are burrs and radial grooves, and whether the threaded part of the flange is complete and intact. Whether the concave and convex flange can fit in naturally, especially the nondestructive testing of the welding flange must be done well, so as to avoid damaging the inside of the welding flange and affecting the performance and service life of the flange.
- 2. Please pay attention to cleaning before installing weld neck flange. After all, the sealing surface of the flange should be tightly connected with washer and bolt. Flange sealing surface shall be cleaned with special cleaning tools and methods to prevent damage of weld neck flange.
- 1. Before connecting the weld neck flange, first arrange the inside and outside of the stainless steel pipe fittings, and then install the flange with slotted ring on the pipe to be connected. Above, the end of the pipe needs 90 degree flanging. After treatment, the end surface of the pipe needs to be polished. After grinding, it should be free of burr, concave convex and deformation, vertical and flat, and need to use special tools to round it.
- 2. The finished flanging short pipe is welded on the pipe, and the O-shaped rubber seal ring and stainless steel seal ring installed on both sides are inserted into the flange with groove ring for sealing. The inner diameter of the inner hole of the sealing ring is the same as that of the pipe, and then the flange hole is connected with bolts. The bolt assembly needs to be tightened symmetrically. When tightening the weld neck flange, please pay attention to the sealing of each joint and meet the required specifications.