How to choose flange products correctly?
Flange is widely used in basic projects such as chemical industry, construction, water supply, drainage, petroleum, light and heavy industry, refrigeration, sanitation, plumbing, fire fighting, electric power, aerospace, shipbuilding and so on. So there are many types of Flanges. How do we choose Flange correctly?
1.The nature of conveying medium: including general medium, special medium, poisonous medium, inflammable and explosive medium;
2.According to the parameters of the medium: working pressure and working temperature, when the medium is certain, the nominal pressure PN of the flange is determined according to the working temperature and working pressure of the medium;
3.Confirm the connection mode and sealing surface form of the flange and the pipe according to the place of use and connection conditions;
4.Confirm flange specifications according to the connection object.
Pipeline flanges can be divided into five basic types according to their connection with pipes: SO Flanges, WN Flanges, Threaded Flanges, Socket Welding Flanges, and Lap Joint Flanges. There are many types of flange sealing surface. Generally RF, FM, MFM, TG, FF, RJ are commonly used.
- SO Flanges: Suitable for carbon steel pipe connections with a nominal pressure not exceeding 2.5MPa. The sealing surface of the flat welding flange can be made into three types: smooth, concave and convex and tongue and groove. Smooth flat-welded flanges are the most widely used. They are mostly used when the medium conditions are relatively mild, such as low-pressure non-purified compressed air and low-pressure circulating water. Its advantage is that it is cheaper.
- WN Flanges: It is used for butt welding of flange and pipe cture, high strength and rigidity, can withstand high temperature and pressure, repeated bending and temperature fluctuations, and has reliable sealing. The butt welding flange with nominal pressure of 0.25～5MPa adopts concave and convex Type sealing surface
- Socket Welding Flange: often used in pipelines with PN≤0MPa and DN≤40
- Lap Joint Flanges: It is often used for medium temperature and pressure that are not high and the medium is corrosive Stronger situation. When the medium is highly corrosive, the part of the flange contacting the medium (flanging nipple) is made of corrosion-resistant high-grade materials such as stainless steel, and the outside is clamped with low-grade materials such as carbon steel flange rings To achieve sealing. Integral flange: The flange is often integrated with equipment, pipes, fittings, valves, etc. This type is commonly used on equipment and valves.