A flanged joint is a detachable joint. There are holes in the flange, bolts can be worn to make the two flanges tightly connected, and the flanges are sealed with gaskets. According to the connected parts, it can be divided into container flange and pipe flange. The pipe flange can be divided into five basic types according to the connection with the pipe: flat welding flange, butt welding flange, thread flange, socket welding flange, loose flange.

■ Flat welding flange

Flat welded steel flange: suitable for carbon steel pipe connection with nominal pressure not exceeding 2.5MPa. The sealing surface of flat welded flange can be made into three types: smooth type, concave and convex and grooved type. Smooth type flat welded flange The application is the largest. It is mostly used in the case of moderate media conditions, such as low pressure non-purified compressed air and low pressure circulating water. Its advantage is that the price is relatively cheap.

■ Butt welding flange

Butt welding flange: It is used for the opposite welding of flange and pipe. Its structure is reasonable, its strength and rigidity are large, it can withstand high temperature and high pressure and repeated bending and temperature fluctuation. The sealing performance is reliable. The nominal pressure is 0.25~2.5MPa. Welding flange with concave and convex sealing surface

■ Socket welding flange

Socket welding flange: commonly used in PN10.0MPa, DN40 pipeline

■ Loose flange (commonly known as looper flange)

Butt welding sleeve flange: It is often used when the medium temperature and pressure are not high and the medium is corrosive. When the medium is corrosive, the part of the flange that contacts the medium (flange short section) is a corrosion-resistant high-grade material such as steel, while the outside is clamped by a flange ring of a low-grade material such as carbon steel. It to achieve a seal

■Integral flange

Integral flange: It is often the integration of flanges with equipment, pipes, fittings, valves, etc. This type is commonly used on equipment and valves.