Welding of carbon steel flanges and stainless steel pipes
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Dear Haihao friends, can carbon steel flanges and stainless steel pipes be welded directly together? Are there any relevant standards to serve as a basis? Thank you all
Why should carbon steel flanges be welded to stainless steel pipes? Can’t we use stainless steel flanges? Direct welding is possible; an appropriate welding rod needs to be selected. However, both will suffer from galvanic corrosion in corrosive media, causing the carbon steel flanges and welds to corrode rapidly. Unless the pipeline medium is very low in corrosivity or non-corrosive.
Search for such topics on the forum. . . There are many. . Yes! Sure! As for the regulations, they generally list a negative list indicating under what circumstances certain actions are prohibited.
It’s possible, but it’s not usually designed that way.
It can also be welded directly, I guess; it depends on whether the medium is corrosive
If a connection is indeed necessary, I have two suggestions for you: 1. Use stainless steel flanges for the connections to the stainless steel pipes; the carbon steel flanges on the other side can be directly fitted together. Of course, it’s best to galvanize the carbon steel flanges on the other side. 2. Make the flanges connecting to the stainless steel pipes into slip-on flanges with flat-weld or butt-weld joints, using galvanized carbon steel for these flanges. The flat-weld and butt-weld joints should be made of stainless steel to match the pipes. This results in flanges that are movable, with the weld joints attached to the pipes. This approach is sufficient for medium and low pressure applications. Welding of different types of steel is not recommended
During design, carbon steel flanges are usually paired first with stainless steel flanges of the same pressure rating, and then the stainless steel flanges are connected to the stainless steel pipes
Sure, you can look up information online on welding different types of steel; there are specialized electrodes for that.
It can be welded; appropriate welding rods and welding techniques need to be selected. Welding of dissimilar steels is common and sometimes inevitable.