When connecting flanges with double-headed bolts, after tightening, how many threads of the bolt protrude from the nut?
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This post was last edited by security on 2011-5-21 07:23. When connecting flanges with double-headed bolts, what is generally required regarding the length of the bolts protruding from the nuts after they have been tightened? Which file contains such provisions.
2-3 threads of fastening will meet the requirements.
Are there any standard regulations available for study?
It seems there are no specifications regarding pipelines; GB50235 doesn’t provide clear guidance on this matter. Refer to section 6.3.8. The specifications in the steel structure standard GB50205 certainly exist, but it’s not easy to apply them to pipeline installation.
The old standard specified 2-3 deductions, while the new standard requires them to be level.
There are actually no relevant standards for this; as long as it’s available and has a similar appearance, that’s fine
0.5 D is enough. It’s half of the bolt’s diameter
As a precaution, we generally use a full cap of 1 cm on both sides. I’m not aware of the relevant standards; experts, please share them.
Section 6.3.8 of GB50235 stipulates that \"the bolts and nuts after tightening should be at the same level\""
It seems to be a common practice for 2–3 threads to protrude; there is no specific standard specifying this. Some standards, such as GB50235 clause 6.3.8, state that \"the bolts and nuts after tightening should be level.\" Some standards require that the protrusion be a certain multiple of the nominal diameter of the thread, and this multiple varies depending on the range of the nominal diameter. In terms of the tightening effect, it’s fine if they are even; for aesthetic reasons, they should extend a little bit. The above statement is not necessarily entirely accurate; it is for reference only
2-3 threads; the requirement now is that it be level with the nut, as long as both ends protrude by the same length There are no strict regulations; as long as the construction party has no special requirements, it’s fine!