What is the maximum gap between flange bolts and bolt holes? What is the basis for the standard?
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What is the maximum gap between flange bolts and bolt holes? What is the basis for the standard? For example, if the flange hole is φ26, is it okay to use M22 flange bolts? Why?
There are standards for flanges and solid parts, why not check the standards. There is such a standard * * standards, there are also industry standards, and there are also some commonly used foreign standards. Implement according to standard specifications. Any deviation from standard implementation should be a sign of irresponsibility for engineering and safety.
ASME 16.9, HG/T 20615, HG/T 20592. The first few pages of the standard have a tolerance description and the size of the bolts to be used.
The bolts are one size smaller than the flange holes.
Thank you for your reply! From the perspective of flanges alone, many standards have stated that the difference between holes and bolts is one level, which is basically 2mm. But why is this so? Judging from the picture specification GB5277, the hole can be larger. So what do the three situations in the specification mean?
HG/T20592 pipe flange has ready-made size requirements for bolts and bolt holes. Basically, they are 2mm larger, the bolts are M16, and the bolt holes are Φ18.
Flange holes generally use bolts that are one size smaller than the flange holes.
Flanges and bolts are used correspondingly according to standards, and you are not allowed to choose by yourself.