Welding on knot of Expansion Joint (Compensator)

[erdyne]

Dear Gentlemen,

I would like to ask one question. We are replacing gus ducts on some of the gas lines in sulfuric acid plant. Contractor firm started to bring material to site but as a process engineer, it looked odd to me that manufacturer made welding on the middle of the knots of every expansion joints all around.(Pictures attached) Is that normal and acceptable? Is this a common practice?

Sincere thanks for your answers in advance!

 

[LittleInch]

They don't look great tbh, but got a drawing of what they are supposed to look like?

This is it for others...

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Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TugboatEng]

Why do they require welding?

Can it work? Sure. The expansion joints eventually get welded to a pipe or a flange. Why couldn't they be welded anywhere else?

Does it work? Most expansion joint failures I have seen are at the welds. All of that welding is just extra sites for a failure to occur.