slip on flanges are used to connect carbon steel pipes, and the nominal pressure shall not exceed 2.5 MPa. The connection methods of slip on flanges include single-sided welding and double-sided nut connection. Only single-sided welding is required for welding, and there is no need to connect the inner hole of the welded pipe with the commonly used flange for low-pressure and medium-pressure pipelines.
According to the movement mode of the forging die, the forging of flat welded flanges can be divided into ring rolling, rotary forging and cross rolling; precision forging can also use rotary forging and ring rolling. Some complex forging processes are completed by one or more processes in order to improve the utilization rate of heat treatment.
Forging method
The forging of flat welded flanges can be divided into free forging and extrusion. Generally, the unheated area at room temperature is called cold forging, and the crystallization temperature zone is called hot forging. When flat welded flanges are forged at low temperature, the change in forging size has little effect. Forging below 700°C will not decarburize the flange surface. The advantage is that it can be formed even if the forging force is small compared to the forging size.During the machining process, the flat welded flange will extend from the vicinity of the die surface to the free surface, which is difficult to ensure precision. Under low forging force, products with complex shapes and high precision can be obtained. Therefore, in order to better process products, the moving direction of the forging die and the rotary forging process are controlled by the computer, such as the forging of large and various large steam turbine blades produced and operated by enterprises.
Features of slip on flange
The slip on flange is a movable flange piece. In fact, the flange is sleeved on the pipe end with a steel ring, flange, etc. In this way, the flange can move on the pipe end. The flange or the steel ring of the flange is usually used with the fittings of the water supply and drainage pipe. When the factory leaves the factory, flanges are designed at both ends of the expansion joint, and bolts are directly used between the pipeline and the equipment to establish a connection.
The slip on flange not only saves space and weight, but also ensures that the joint does not leak and has a good sealing performance. Then, replace the flange gasket sealing ring to ensure that the sealing surface matches the sealing surface. Due to the reduced force-receiving area of the forging, the size of the compact flange can be reduced because the diameter of the sealing ring is reduced, so the cross-section of the sealing working surface is continuously reduced. In this way, only a small amount of pressure is required to compress the sealing surface. As the pressure decreases, the size of the bolts and the number of bolts required are also reduced, thereby designing lightweight products.
The quality of slip on flanges is good. The main standards are national standard, electric standard, German standard, American standard, Japanese standard, etc.; the main materials of the flange are carbon steel, alloy steel and stainless steel; the main anti-corrosion treatment is oil and galvanized , slip on flanges have good pressure and temperature resistance, and are usually suitable for high pressure and high temperature working environments.
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