Pressure vessel flange connection flange according to the flange ring is divided into: the overall flange, loose flange and any flange. China's most popular JB / T4701-4703 standard pressure vessel flange There are three types: alpha-welded flange, welded flange and beta-necked welded flange, where influenza A, B flat welding flange belong to any flange. Flanges and gaskets, fasteners, collectively known as the flange joints, flange joints are used in engineering design is very common, involves a very wide range of parts, but also the process of engineering design and the use of key parts prone to problems . Flange adapter design is an important part of the pressure vessel design. Influenza in the selection criteria and the calculation of non-standard flange flange influenza, designers choose materials unreasonable phenomenon is more serious, and even the use of beta-necked welded flange welded flange welded flange instead of Influenza situation is more unnecessary waste. Therefore, it is necessary to discuss the selection and calculation commonly used for influenza A flat welding flanges. Specifications: DN300 ~ 3000 pressure vessel flange Industry: Building HVAC electricity supply pressure vessel fittings, pressure pipe fittings.