Welding of pipes made of different materials
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I would like to ask everyone: 1. Can stainless steel pipes be welded to carbon steel valves, and can carbon steel pipes be welded to stainless steel valves? 2. The best methods for connecting stainless steel pipes to carbon steel pipes (flanges or welding); what are the precautions for welding? 3. What is the best way to connect pipes with different diameters (such as 219 and 208)? Thank you all!
This post was last edited by Keep running on 2016-7-13 09:52. 1-Stainless steel cannot be welded directly to carbon steel. 2- Of course, a flange connection will work fine. 3-That’s not referred to as a difference in diameter; it’s rather a difference in wall thickness. Tubing is welded after beveling is applied, and of course, a too large difference in wall thickness isn’t acceptable either. There are specific standard requirements for this. If connection is necessary, then use an adapter joint
This post was last edited by Keep running on 2016-7-13 09:53. The first and second cases are known as dissimilar steel welding, and they occur in such situations. The third category refers to pipes with the same diameter but belonging to different series, that is, pipes according to American standards and Chinese standards, or imperial pipes and metric pipes
Stainless steel and carbon steel can be welded together, using special welding electrodes known as transition electrodes. As for the AB series of pipes, the differences in diameter are not significant, and they can still be welded; however, the result isn’t very aesthetically pleasing. In most temporary applications, these pipes are simply used as is. For actual projects, it’s necessary to purchase fittings from a specific series
This post was last edited by Keep running on 2016-7-13 09:56. 1. Can stainless steel pipes be welded to carbon steel valves, or can carbon steel pipes be welded to stainless steel valves? Stainless steel and carbon steel can be welded to each other; welding is permitted. Welding materials such as E309 or ER309 should generally be used. 2. The best methods for connecting stainless steel pipes to carbon steel pipes (flanges or welding); what are the precautions for welding? There is no such thing as best or worst for this. To prevent leakage, welding is used. No fear of leakage – use flanges. For welding, use the correct welding rod. Be aware of cracks. 3. What is the best way to connect pipes with different diameters (such as 219 and 208)? This is used to make a reducer.
The guys upstairs have all said very sensible things.
If you don’t share your opinion, it seems a bit pointless~ For butt-welded pipe connections, in addition to welded fittings, you can consider using plug-welded or threaded fittings. Give an example and I’ll give you extra points. :handshake
The last edit to this post was made by Keep running on 2016-7-13 09:57. 1. It’s possible, but try to avoid such situations as much as possible； 2. Of course, it’s a flange connection. 3. Mixed installation of the AB series – this should also be avoided
The pipeline is made of stainless steel, so why install a carbon steel valve? Doesn’t that render the stainless steel of the pipeline pointless?
I remember that for 8-inch pipelines, both the American standard and the national standard specify an outer diameter of 219. Which series does a pipeline with an outer diameter of 208 belong to?
The connection of reducers is generally achieved through groove welding, which provides better stress distribution. Of course, for occasions with lower requirements, you can also use the other methods you mentioned.