High-Pressure flanges: Flanges for piping or equipment connections with pressures above 10 MPa. At present, it mainly includes traditional high pressure flanges and high pressure self-tightening flanges.
1. The sealing principle is plastic deformation
2, by bolt connection
3, the bolt should withstand the tensile force, temperature difference stress, and bear a lot of external stress such as bending moment, torque, etc.
4, bulky, heavy weight, installation is very difficult.
5, the sealing performance is unstable, especially in the case of harsh (high temperature, high pressure, medium is highly toxic), it is easy to produce leakage, causing serious consequences.
The product grades and technical requirements for high-pressure flanges are to comply with the relevant requirements. A carbon steel or austenitic stainless steel forging with a nominal pressure is allowed to be manufactured using Class I forgings. Forgings with a nominal pressure between 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.
Die Forging High Pressure Flanges Normally, high pressure flanges are manufactured using forging or forging technology. If it is to be made of steel or steel, it must meet these requirements. The high-pressure flange must be tested by ultrasonic flaw detection, 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. High pressure 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 Class II requirements in JB4730, the results of ultrasonic flaw detection of high pressure flanges must meet the Class I standard requirements of JB4730.
Common die forging equipment for die forging equipment includes die forging hammer, hot forging press, flat forging machine and friction press.
Generally speaking, forged flanges are of better quality, generally produced by die forging, with fine crystal structure and high strength, of course, the price is also more expensive. Both the cast flange and the forged flange are common methods of manufacturing flanges. See the strength requirements of the parts to be used. If the requirements are not high, you can also use the turning flange.
Forging high pressure flange high pressure butt flange forging blanks are subject to deformation and work hardening during cold forging, so that the forging die is subjected to high loads. Therefore, it is necessary to use high strength forging die and hard to prevent wear and adhesion. Lubricating film treatment method. In addition, in order to prevent cracking of the billet, intermediate annealing is performed as needed to ensure the required deformability. In order to maintain a good lubrication state, the billet can be phosphatized. A butt weld flange is a flange that has a neck and is transitioned by a round pipe and is butt welded to the pipe. Butt weld flange is one of the flanged pipe fittings. It is widely used and promoted in different fields and industries. The applicable range is different in use, and the environment to be used is different. It needs to be used according to certain conditions.