The general key role of stainless steel flanges in the use of pipelines is to connect, and now it is often used in the installation of various pipelines, especially large and medium distance metal material transportation pipelines for long-term application of pipelines and flange selection, and stainless steel flanges are applied at the junction of the pipeline as the socket of each section, rather than using the method of immediately connecting the pipeline. That is more reliable, the socket is also more robust, so today most of the use of stainless steel flanges, then stainless steel flanges in the case of welding pipes what are the common problems? What does it actually do? Today, I will talk to you about the common problems and effects of stainless steel flange welded pipes, below to see it!
First, the common problems of stainless steel flange welding pipes
1, stainless steel flange in welding, subjected to repeated heating will dissolve the cementite, reflecting the carburizing will reduce corrosion resistance and physical properties. Therefore, when welding stainless steel flanges, it is necessary to pay attention to the need not to carry out repeated heating, to avoid reflecting the corrosion resistance and physical properties of the stainless steel flanges.
2, pay attention to stainless steel flange in order to avoid due to heating caused by eye erosion, welding stainless steel flange welding current is not suitable for large, less than carbon steel electrode 20% up and down, electric arc is not suitable for too long, virtual beam fast cooling, to narrow weld is appropriate. Therefore, the use of stainless steel flange welding rod to effectively manipulate the welding current, to avoid excessive current caused by eye erosion, harm the welding quality of stainless steel flange.
3, note that in the case of welding, the electrode should be maintained dry, titanium calcium type should be 150℃ dry for 1 hour, low a hydrogen type should be 200-250℃ dry for 1 hour (can not be repeated air drying, otherwise the welding core is very easy to crack off), to avoid the electrode core oil and it dirty, to prevent welding to improve the carbon content of stainless steel butt welding flange and harm the quality of welding parts.
4, pay attention to chromium stainless steel butt welding flange after the necrotic American standard flange is very large, very easy to cause cracks. If you choose the same kind of chromium stainless steel plate electrode (G202, G207) welding, be sure to carry out heating above 300 ° C and slow cooling violence around 700 ° C after welding. If the welding parts can not be carried out post-welding heat treatment, the stainless steel plate butt welding flange electrode (A107, A207) should be used.
5, pay attention to the surface of the stainless steel flange should be smooth and clean, can be allowed to have a ring shallow slot, but not spot scars, sand holes and radiation to the pipe groove, the two flange surface symmetry, strict touch.
6, pay attention to the center line of the stainless steel flange plan should be vertically bisecting the center line of the pipeline, and its error is not more than 1-2.5 mm.
7, pay attention to the stainless steel flange flange hole distance part (parallel line accurate measurement) tolerance of 0.5-1.0mm; The allowable deviation between the center line of the flange hole and the center line of the pipeline is 1-3mm; Two-flange plan tolerance error 0.2-0.3 mm.
8, pay attention to stainless steel flange and pipe welding, should pay attention to welding ground stress deformation.
Second, the role of stainless steel flange
1, in the pipeline socket is usually a very sensitive area, and the application of stainless steel flange welded pipe is enough to maintain a higher tightness and durability, and then improve the durability of the pipeline.
2, the application of stainless steel flange can be more casually dismantled must be dismantled a damaged section of the pipeline, or in the case of line change is more easy to disassemble.
3, stainless steel flanges also have another key effect is that in the case of a certain section of pipeline does not need to be accessed again, it must be blocked in place, then the application of flanges can easily seal the pipeline. Exorcise bia award Qu Watch for H Wanzhi yuan in Memna Xelu hoop tip garden ke target zone China Polembia Qiu orτground
4, in addition, the stainless steel flange is more conducive to disassembly and inspection of pipeline conditions, so that it is very convenient and conducive to maintenance inspectors.
Above is all the contents of the common problems and effects of stainless steel flange welding pipes, in fact, in the case of welding is composed of many common problems, such as: Pay attention to avoid excessive current flow, pay attention to the need not to repeatable heating these, this is very important, in addition to most application flanges is due to the efficacy of the flange, the convenience of the flange, so the stainless steel flange will be loved by everyone.
