Problems with JB/T4702-2000 flange splices (online, etc.)
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Can holes be made in the flange stubs specified in JB/T4702-2000? This post was last edited by jwl127 on 2007-12-27 16:01.]
Making small holes should be possible, but it’s necessary to calculate the reinforcement required for those holes
Sure, anywhere is fine as long as the intensity is sufficient; there are no restrictions on the location – you can drive wherever you want
The short section is also a connector; why can’t it be opened? However, the creation of openings also needs to follow certain standards; issues such as openings being located on welds can arise.
Punching can be done as long as the strength is sufficient
It is best not to operate it, as it is subject not only to primary film stress but also to secondary stress.
When calculating type B flanges, the requirements regarding the thickness and length of the splices are mainly due to the factor of rotational inertial moment. It is acceptable to make small holes, as long as the reinforcement requirements are met; since full penetration is ensured, the rotational inertial moment is not a problem (which can be compensated for by the fittings). If larger holes are made, it depends on the specific circumstances – a reinforcing ring can be added to compensate for the loss in rotational inertial moment
What size counts as a small hole? It’s too general. I think holes cannot be made before performing the relevant analysis and calculations. If you can’t calculate, don’t open it there.
It’s best not to drive. Think about it: would you make holes in the beveled portion of a butt weld flange?
A DN25 size is fine; going larger will cause problems.
Holes must also be made in accordance with standards; holes can be created as long as the strength is sufficient.