Flange is a disc-shaped part, the most common in pipeline engineering, flanges are used in pairs and matching flanges on the valve. In pipeline engineering, flanges are mainly used for pipeline connection. In the pipelines that need to be connected, a flange plate is installed for various installations. The low-pressure pipeline can use the wire connection flange, and the welding flange is used for the pressure above 4 kg. A gasket is added between the two flanges and then tightened with bolts. Flanges with different pressures have different thicknesses and use different bolts.
　　 When the stainless steel elbow is welded, carbides will be precipitated after repeated heating, and the refracted carbides will reduce the corrosion resistance and mechanical properties. Therefore, when welding stainless steel elbows, do not repeat heating to prevent the reflection of carbides from affecting the corrosion resistance and mechanical properties of stainless steel elbows.

　　 In order to prevent corrosion between eyes due to heating, the welding current should not be too large when welding stainless steel elbows, which is about 20% less than that of carbon steel electrodes. The arc should not be too long, and the interlayer cooling should be fast. Therefore, when welding with stainless steel elbow electrodes, the welding current should be controlled reasonably to prevent excessive current from causing corrosion between the eyes and affecting the welding quality of stainless steel elbows.

In the actual production of the eccentric size head, different elements are added to it for different functions and strengths, and certain production standards and methods are used to add, and it has certain performance in its use. The eccentric size head is characterized by significantly high strength. Carbon steel with the same amount of carbon has good toughness and plasticity as well as good weldability and corrosion resistance. In order to improve and improve the performance of steel, other alloying elements, such as silicon and manganese, are added on the basis of carbon steel. , Chromium, nickel, tungsten, vanadium, titanium, etc., this kind of steel is called alloy steel.

The eccentric size head has different properties according to the different alloy elements added, such as high wear resistance, corrosion resistance, low temperature resistance, high magnetism and other good special properties. The middle of the eccentric size head is the main pipe section, and the two ends are eccentric Straight pipe section, there is an eccentric diameter reduction transition section between the main pipe section and the eccentric straight pipe section, and the bottom line of the eccentric size head is kept unchanged in a straight line; the preparation method of the eccentric size head is to use multiple sets of grading molds to directly perform eccentric diameter reduction on the metal pipe First, leave the main pipe section in the middle of the whole metal pipe, and then according to the requirements of the reducing angle, use multiple sets of grading mold compression molds, and press them step by step. The eccentric size head processed by the method of the present invention, the whole eccentric size head There is no welding seam on the upper side; the eccentric size head is used as a special pipe for corrosive liquids, which can extend the service life of the eccentric size head, especially used as the shell of the downhole eccentric water distributor. Corrosion and cracking at the weld joint; flexible production technology, eccentric size heads of any diameter and eccentric straight pipe section of any length can be processed.

　　 The size of the eccentric size head is different, and the pipes connected are also different for different industries. In electric power, mining, metallurgy and other industries, the transportation and output of materials are all carried out at close distances and high pressure. The pipelines are subjected to considerable pressure and are subject to severe wear. It is difficult for a single material pipeline to meet this working condition. Requirements, especially for pipe fittings such as elbows, concentric heads, and stamping elbows, because of their safety in use and service life, the emphasis is on improving the toughness, impact resistance, and wear resistance of the pipeline lining. At the same time, the overall strength of pipes and elbows must be considered.
　　Before bonding the eccentric size head, wipe the socket side and the outside of the socket with a dry cloth. When there is oil on the surface, wipe it with acetone. Pay attention to the following points:
　　1. Control caliber: DIN standard, 3A/IDF standard, ISO standard;
　　2. International industrial standards: DIN, ISO, SMS, 3A, IDF, etc.;
　　3. Product material: stainless steel 304, 316, 316L;