The structure of the flange is relatively simple
It consists of the upper and lower flange pieces, the middle gasket, and several bolts and nuts. A flange with a neck and connected to the pipe. Repair welding flanges are suitable for pipelines with large fluctuations in pressure or temperature, or pipelines with high temperature, high pressure and low temperature, and are also used for conveying pipelines with expensive, flammable and explosive media. The butt welding flange is not easy to deform, well sealed and widely used. The nominal pressure PN is about 16MPa. The docking size of the flange changes with the nominal pressure, resulting in the equal diameter flange often cannot docking, ordering, manufacturing, storage and transportation, installation, maintenance, maintenance, and other actual work is very troublesome. The 0.25,0.6 MPa flange adopts 1.0 MPa docking size, and the thickness still adopts the original three specifications, so as to realize the simplicity of the docking size. The welding flange is not easy to deform, good sealing, widely used, suitable for pressure or temperature large fluctuation pipeline or high temperature, high temperature and low temperature pipeline, the advantage is relatively cheap, the price is, the nominal pressure does not exceed 2.5MPa; also used to transport expensive, flammable and explosive medium pipeline, the nominal pressure is about PN16MPa. The pressure grade, material, standard of the welding flange has different characteristics and characteristics, used in accordance with certain principles and methods, can be produced and processed according to the corresponding standards, to ensure a good use value and role in use. Pressure grade of butt welding flange: 0.6Mpa~32Mpa (150Lb~2500Lb), material: 201.202.301.302.303.304L.309S.310S,316.316L.317.317L. 321.410.420 et al. Common production standards for welding flange: Ministry of Chemical Industry standard HG / T20592-2009, HG / T20615-2009, national standard GB/T9115.1-2000, GB/T9115.2-2000, GB/T9115.3-2000, GB/T9115.4-2000, mechanical department standard JB/T86.2-94, Marine standard CB / T47-1999.
