Specifications for measuring flange spacing to determine whether bolts are tightened
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It is said that there are regulations stipulating that for high-weight flanges (with RTJ octagonal ring gaskets), it is possible to determine whether the bolts have been tightened properly after installation by measuring the distance between the two flanges (as the gasket gets compressed). I wonder if anyone here is aware of such regulations; they are likely to be part of the API standards.
I don’t know. But there was a former colleague; when they were working on it, the client demanded that the surfaces of the two flanges be twisted together until they stuck together, which caused complete deformation.
It deforms noticeably as soon as it’s stuck on; how strong must that adhesive be?
Flange locking does not allow the flange to deform; if the flange does deform, either forceful alignment is used or the material is inappropriate
This counts as the former, strong pairing.
This shouldn’t be a fixed value, right? It depends on the flange material, the thickness and material of the gasket, as well as the torque used to tighten the screws.
Each pair of flanges has a designed locking force, which needs to be calculated
A person who has been involved in installations told me that they tightened the bolts to a certain degree, and ultimately determined that level by measuring the distance between the two flanges; he said it was in accordance with the regulations, but he couldn’t remember the regulation number.
Requirements for flange locking are specified in Asami’s B31.1 and 31.3; refer to the specifications for details
Could you let me know which one it is? There are too many of them, so it’s hard to find. Thank you.