Can the flange be welded again?
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The company has a flange that was manufactured to CLASS 600 standards in accordance with HG20615. During the renovation, it was cut using flame cutting and then rewelded, without any heat treatment being applied. I would like to ask now whether flanges can be reused in this way, and if there are any relevant regulatory requirements. Thank you
Flange manufacturing should involve heat treatment, right? Could direct flame cutting create a heat-affected zone that leads to changes in the microstructural properties? ?
Polishing, beveling, and other such measures are required. Or use it at a lower level
Generally, there’s no problem; it’s your first time welding, and no heat treatment was done after welding either.
I don’t think so; after all this hassle, it’s better to just buy a new one
It’s about considering that it has already been welded once – will welding it again cause the overlapping area to increase further?
It has been in use for 2 years since construction was completed; a circumferential crack was found on the left and right sides of the flange body, 1 cm above the weld. An analysis of the cause is required
The reuse of flanges, including the effects of thermal processes on the material and on deformation: 1. Effects of thermal processes on the material – as long as the heat-affected zone of the original weld is thoroughly removed, re-welding is possible without problems. 2. The impact of thermal processes on flange deformation, especially in flanges that have been in use for a long time, are of larger size, and are of lower quality; multiple weldings will exacerbate deformation, which is detrimental to sealing performance. It is best to check for deformation or make a cut on the sealing surface before welding.