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How should flange manufacturers weld?

How should flange manufacturers weld?

Stainless steel flanges are widely used in oil, water and natural gas pipelines, which are mostly under certain pressure. This thin bellows is generally welded because it is too thin (about 0.2 mm) and difficult to weld. Welding methods include welding, brazing, and the like. one. Preparation before welding 1. Remove oil and other contaminants from the stainless steel corrugated flange. Assuming weld cracks and leaks, the original weld scars should be removed, the flanged straight pipe should be polished with metallic luster, the bellows straight pipe is too thin to be ground, ground and cleaned, and the bright light should be polished with a handcraft emery cloth. flange 2. Welding assembly: The equipment bay is 0, because the machining error is sometimes too large, and the welding is easy to burn through. The fusion treatment plan can be stacked on the surfacing layer of the flanged pipe straight pipe (generally 3~5Mm), and the processing is 0. ~0.05mm open space or hand ground. If the sleeve does not fit, rotate or straighten the OD of the small flanged pipe until the fit stops.

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Heating temperature of butt welding flange

Heating temperature of butt welding flange

The heating temperature of the butt welding flange is that the austenitization temperature of the material is higher than this temperature. The principal compressive stress of the inner wall of the head can not be less than the temperature, the yield limit of the material, the maximum temperature of A335P22 and A335P91 are 850-900, 900-950 and 900-1000 respectively, the temperature measurement method is fixed far infrared thermometer and manual far infrared thermometer. The butt welding flange is directly controlled by the flow regulation of the hydraulic system, the principle of determining the speed of the primary compressive stress of the inner wall butt welding flange is less than the yield limit temperature of the material, and the slender outer wall is less than the maximum elongation of the material at this temperature, The expansion coefficient, air permeability and intermediate frequency power of the butt welding flange material are large, the forward speed is fast, the forward speed and productivity are improved, but the thickness reduction rate of the butt welding flange is increased.

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The performance and advantages of large flanges

The performance and advantages of large flanges

Flange connection is a detachable connection, which can be connected according to different parts to ensure the normal connection of flanges. Flanges have different classification standards and classifications, and can be divided into container flanges and pipe flanges according to the connected components. According to the structure type, there are integral flanges, looper flanges and threaded flanges. The common integral flanges of large flanges are flat welding flanges and butt welding flanges. Flat welding flanges have poor rigidity and are suitable for occasions where the pressure is p≤4MPa; butt welding flanges, also known as high neck flanges, have higher rigidity and are suitable for occasions with high pressure and temperature. There are three types of flange sealing surfaces: flat sealing surface, suitable for occasions where the pressure is not high and the medium is non-toxic; concave-convex sealing surface, suitable for occasions with slightly higher pressure; tongue and groove sealing surface, suitable for flammable and explosive , toxic media and occasions with high pressure. Flanged pipe fittings of different properties have good product performance in different fields, and are suitable for different occasions and spaces, resulting in different effects. Ordinary rubber gaskets are suitable for occasions where the temperature is lower than 120 °C; asbestos rubber gaskets are suitable for occasions where the temperature of water vapor is lower than 450 °C, the temperature of oil is lower than 350 °C, and the pressure is lower than 5MPa. The medium, commonly used is acid-resistant asbestos board. Large flanges are used in high-pressure equipment and pipelines, using copper, aluminum, No. 10 steel, stainless steel lens or other shapes of metal gaskets. The contact width between the high-pressure gasket and the sealing surface of the large flange is very narrow (line contact), and the processing finish of the sealing surface and the gasket is high. The gasket of a large flange is a ring made of a material that can produce plastic deformation and has a certain strength. Most of the gaskets are cut from non-metallic sheets, or are made by professional factories according to the specified size, and their materials are asbestos rubber sheets, asbestos sheets, polyethylene sheets, etc.; Metal clad gaskets made of non-metallic materials such as wrapping; there is also a spiral wound gasket made of thin steel strips and asbestos strips. Large flanges will have different use values ​​in use, and have different production effects and uses. The material of the large flange is different, and the production and processing technology will also be different, so pay attention to the method when using and processing the large flange, and use it according to certain procedures and methods.

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It is unlikely that the growth rate of stainless steel flange exports will further decline

It is unlikely that the growth rate of stainless steel flange exports will further decline

Recently, the market demand for stainless steel flanges has stabilized, and the economic growth rate has basically bottomed out. Market demand plays a decisive role in economic growth. In 2015, the growth trend of consumption, export, and investment demand is expected to stabilize. Based on this, it can be judged that the economic growth rate has basically bottomed out. The world economy continues to recover, and although there are risks, it is unlikely that the growth rate of stainless steel flange exports will further decline. The forecast values ​​of China's economy and global economic growth agree that the recovery of the US economy in 2015 will be a bright spot, and the European economy will continue to grow despite increasing difficulties. Improved stability.

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Flat welding flange characteristics, technical parameters and forging methods

Flat welding flange characteristics, technical parameters and forging methods

In the initial stage of forging deformation of flat welding flange, due to the easy deformation of the porous preform, the deformation force is small, and the density increases rapidly. In the later stage of forging, since most of the pores are closed, the deformation resistance increases, and the deformation force required to eliminate the remaining pores increases rapidly. The deformation resistance is closely related to the deformation temperature, and a higher deformation temperature is beneficial to densification and reduces the deformation resistance. The higher deformation rate is also beneficial to the densification of the flat welded flange.

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