The flange is connected to the part between the pipe and pipe, connecting pipe used for end flange in between; also useful equipment import and export of, for the connection between the two devices, such as the reducer flange. Flange connection or flange connection, is defined by the flange, gasket and bolt three are connected as a group of combined sealing structure of the detachable connection. Pipe flange refers to the pipeline installation of piping flange, used in equipment refers to equipment import and export flange. There are holes on the flange, bolt the two flange connect. The flange gasket seal. Sub threaded flange connection (threaded connection) flange, welding flange and clamp flange. Flanges are used in pairs, low-pressure pipeline can use the wire connected flange, four kg more than the use of pressure welding flange. Between the two flange with a sealing gasket, and then tighten the bolts. The different pressure of different thickness of flange, bolt they use are different. Pump and valve, connection and pipe, these equipment locally, also made the corresponding flange shape, also known as the flange connection. In general the two plane surrounding the use of bolted connection parts and closed, generally referred to as "flange", such as ventilation pipeline connection, the parts can be called "flange type parts". But this connection is only a partial one device, such as a connecting flange and a water pump, water pump is not good to call "flange type parts". Relatively small such as valves and so on, can be called "flange type parts".
Butt welding flanges are often used in environments where media conditions are relatively mild, such as low pressure non-purified compressed air and low pressure circulating water. The advantage is that the price is relatively cheap. The sealing surface of the welding flange can be divided into three types: smooth, concave and convex and grooved. Smooth butt weld flanges are used in a wide range of applications, and the other two types of butt weld flanges are also used in many applications. Butt Welding has a reasonable structure, high strength and rigidity, and can withstand various harsh environments such as high temperature and high pressure, repeated bending and temperature fluctuation, and does not reduce the sealing performance.
A butt weld flange is a type of pipe and refers to a flange with a neck that has a transition of a round pipe and is butt welded to the pipe. It is widely used at present because Butt Welding is not easy to be deformed, sealed, and has a wide range of uses, and has corresponding rigidity and elasticity requirements and a reasonable butt welding thinning transition.
At the same time, because the distance between the welding joint and the joint surface is large, the joint surface can be protected from the welding temperature deformation, and a relatively complicated structure is adopted, which is suitable for pipelines with high pressure or temperature fluctuation or high temperature, high pressure and low temperature pipelines. It is generally used for the connection of pipes and valves with PN greater than 2.5 MPa; it is also used to transport expensive, flammable and explosive media. In the production process, the welding flange is strictly controlled in the production and welding to ensure that it can fully play its role and value in production and use.
Butt welding flange refers to a flange with a neck and a round tube transition and is butt welded to the pipe. It is not easy to be deformed, has good sealing, is widely used, has corresponding rigidity and elasticity requirements, and has a reasonable butt welding thinning transition. . The relevant information on the welding flange is as follows:
Butt weld flanges are especially suitable for pipelines with high pressure or temperature fluctuations or high temperature, high pressure and low temperature pipelines. They are generally used for the connection of pipes and valves with PN greater than 2.5 MPa, and also for expensive, flammable and explosive transportation. On the tubing of the media.
The product grade and technical requirements for the butt weld flange are to comply with the relevant requirements in JB4726-4728. Carbon steel or austenitic stainless steel forgings with a nominal pressure of 0.25MP-1.0MPa are permitted, allowing them to be manufactured with Class I forgings. Forgings with a nominal pressure between 1.6 MPa and 6.3 MPa shall meet the requirements of Class II or Class II forgings. For forgings for flanges with a nominal pressure of not less than 10.0 MPa, chrome-molybdenum steel forgings with a nominal pressure of more than 4.0 MPa, ferritic steel forgings with a nominal pressure of more than 1.6 MPa and an operating temperature not exceeding -20 ° C, such flat welding Flange forgings must comply with the relevant requirements for Class III forgings. Normally, the butt weld flanges are manufactured using forging or forging techniques. If it is to be made of steel or steel, it must meet these requirements.
The butt welding flange factory must pass the ultrasonic flaw detection test, and there should be no delamination defects after inspection. It is to be cut into strips along the rolling direction of the steel, and it is butt-welded into a ring shape by a bending process, and at the same time, the surface of the steel is formed into a ring cylinder surface, and it is not possible to machine the steel sheet material into a neck. Butt welding flange. For the butt weld of the ring, it is necessary to adopt the form of full penetration weld. The butt weld of the ring must be heat treated after welding, and the test of 100% radiation or ultrasonic flaw detection should be carried out, and the results of the radiographic inspection should be consistent. For the Class II requirements in JB4730, the results of ultrasonic flaw detection of Butt Welding must meet the Class I standard requirements of JB4730. Butt weld flanges are necked, while flat weld flanges are not. If it is for safety reasons, it is best to use butt welding. If it is normal medium, the pressure is not high, and the leakage will not cause danger.Source:China Stainless Steel Flanges Manufacturer - Yaang Pipe Industry Co., Limited (www.yaang.com)