Butt welding flange, also known as high neck flange or large tail flange, is a type of pipe fitting. It refers to a flange with a neck and a transition of a round pipe and is welded to the pipe. The butt welding flange is not easily deformed. It is well sealed and widely used. It is suitable for pipelines with high pressure or temperature fluctuations or high temperature, high pressure and low temperature pipelines. The advantage is that the price is cheap, the nominal pressure does not exceed 2.5MPa; it is also used for transportation expensive, flammable and explosive. On the pipeline of the medium, the nominal pressure is around PN16MPa.
Use an accurate installation sequence for the welded flange:
- 1. Firstly, the inner and outer sides of the connected stainless steel pipe fittings should be finished before connecting the butt welding flange.
- 2. Install the flanges with grooved rings on the pipe to be connected.
- 3. The port of the pipe needs 90 degree flanging process. After processing, the port plane requirements of the pipe are polished. After grinding, it should be vertical and flat, and there are no doubts about burrs, bumps and deformations, and the nozzle needs to be rounded with special tools. .
- 4. Another simple method is to use the finished product to make a short pipe and then weld it to the pipe.
- 5. Insert the O-shaped rubber sealing ring stainless steel sealing ring installed on both sides in the flange with grooved ring. The inner diameter of the seal ring is the same as the inner diameter of the pipe.
- 6. Then connect the flange holes with bolts, and the bolt assemblies should be tightened symmetrically.
- 7. When tightening the Shandong butt welding flange, it is necessary to pay attention to the tightness of each joint, and it is necessary to reach the required specifications.
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. The welding flange is not easy to be deformed, sealed, and widely used. It is suitable for pipelines with high pressure or temperature fluctuations or high temperature, high pressure and low temperature pipelines. The strength is cheaper, the nominal pressure does not exceed 2.5MPa; also used for conveying quotes. On the pipeline of expensive, flammable and explosive medium, the nominal pressure is around PN16MPa.
There are two techniques for making welded flanges:
- The first type is die forging, which is to heat the steel material in a heating furnace to 1200 C, and then put it into a mold of the corresponding specification for forging.
- The second type is free forging. The material is heated to 1200 C in a heating furnace, and then the square material is forged into the shape of a round cake. The material is punched and the special material is used to ream the punched material to the required size.
Technical requirements for welding flanges:
The welding flange connection is easy to use and can withstand relatively large pressures. For welded flanges, materials are produced according to different grades of pressure. From low-pressure asbestos pads, high-pressure asbestos pads to metal mats.
In industrial piping, the use of butt flange connections is very broad. In the home, the pipe diameter is small and low pressure, and the connection to the weld flange is not visible. If you are in a boiler room or production site, there are flanged pipes and equipment products everywhere.
In the actual production process, the welding flange adopts certain technical parameters and requirements for production and application to ensure correct use and promotion according to certain methods and principles. Colleagues use certain process methods and principles for production and welding. To ensure the reliable quality of the welded flange in use.
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 1.6MPA and 6.3MPA shall meet the requirements of Class II or Class II forgings. For forgings for flanges with a nominal pressure of not less than 10.0MPA, chrome-molybdenum steel forgings with a nominal pressure of more than 4.0MPA, ferritic steel forgings with a nominal pressure of more than 1.6MPA and an operating temperature not exceeding -20 degrees Celsius, 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 weld flange must be subjected to 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. 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 the welded flange must meet the Class I standard requirements of JB4730.
Source: China Stainless Steel Flanges Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)