The flange is the part of the shaft and the shaft that is connected to each other for the connection between the ends of the pipe. It is also used for the flange on the inlet and outlet of the device for the connection between two devices, such as a centrifugal pump flange. A flange connection or a flange joint refers to a detachable connection in which a flange, a gasket and a bolt are connected to each other as a combined sealing structure. Pipe flange refers to the flange used for piping in the pipeline installation. It is used on the equipment to refer to the inlet and outlet flanges of the equipment. There are holes in the flange, and the bolts make the two flanges tightly connected. The flanges are sealed with gaskets. Flange threaded connection (threaded connection) flange, welded flange and clip flange. Flanges are used in pairs. Low-pressure pipes can be used with wire-bonded flanges, and welded flanges are used for pressures above four kilograms. A gasket is placed between the two flanges and then bolted. Different flange thicknesses for different pressures use different bolts. Pumps and valves, when connected to the pipeline, the parts of these equipment are also made into the corresponding flange shape, also known as flange connection.
According to the connection type of flange connection, it can be divided into: plate type flat welding flange, neck flat welding flange, neck butt welding flange, socket welding flange, thread flange, flange cover, neck butt weld ring Loose flange, flat welding ring loose flange, ring groove flange and flange cover, large diameter flat flange, large diameter high neck flange, eight-word blind plate, butt weld ring loose flange, etc.
Standard
There are two main systems for the international pipe flange standard, namely the European pipe flange system represented by German DIN (including the former Soviet Union) and the American pipe flange system represented by the American ANSI pipe flange. In addition, there are Japanese JIS pipe flanges, but they are generally only used for public works in petrochemical plants, and have little impact internationally. Now introduce the national pipe flanges as follows:
1. European system pipe flange represented by Germany and the former Soviet Union
2. American system pipe flange standard, represented by ANSI B16.5 and ANSI B 16.47
3. British and French pipe flange standards, the two countries have two casing flange standards.
In summary, the internationally accepted pipe flange standard can be summarized as two different, non-interchangeable pipe flange systems: a European pipe flange system represented by Germany; the other is represented by the United States. American pipe flange system.
IOS7005-1 is a standard promulgated by the International Organization for Standardization in 1992. This standard is actually a standard for pipe flanges that combines two series of pipe flanges from the United States and Germany.
Common malfunctions
In the continuous production of modern industry, the flange is inevitably leaked due to the influence of medium corrosion, erosion, temperature, pressure, vibration and other factors. Leakage of the flange is easily caused by the error in the size of the sealing surface, the aging of the sealing element, and the improper installation and fastening. If the flange leakage problem cannot be dealt with in time, the leakage will rapidly expand under the scouring of the medium, causing the loss of materials and the destruction of the production environment, causing the enterprises to stop production and cause huge economic losses. If it is a toxic, harmful, flammable and explosive medium, it may cause serious accidents such as personnel poisoning, fire and explosion.
The traditional method for solving flange leakage is to replace the sealing element and apply the sealant or replace the flange and the pipe, but the method has great limitations, and some leakage is limited by the requirements of the work environment safety, and cannot be solved on site. . It is now possible to use polymer composite materials for on-site plugging, among which the more mature Fushun blue system is applied. It is an ideal method, especially in the case of flammable and explosive occasions, it also shows its unique superiority. The polymer composite technology technology is simple, safe, and low in cost. It can solve most of the flange leakage problems for enterprises, eliminate safety hazards, and save more maintenance costs for enterprises.
