Dear All

I would like to know whether B16.5 permit to use Standard flanges with Metric Bolting instead of inches bolt, Vessel is constructed as per ASME SEC VIII DIV-1.

Can B16.5 flanges with Metric bolting be considered Standard or Non-Standard flanges?

Thanking you & with regards
Vishal Tailor

Hello Vishal

B16.5 does not consider metric bolting, and that is strange considering the majority of users employ the metric system. It is only in America (mainly) that we use the old fashioned Imperial system.

I am from South Africa. There we specified the nearest metric size bolt that fit the flange bolt holes. That is about the only thing we can do.

Dear Mr. Ray

Thank you for your reply. What about Code stamp vessel. Does AI accept Metric Bolting to Standard flanges? there is any possible way to convince AI as equivalent bolt.
in my observation, it can't, let take example 1.5 inch bolt = 25.4 x 1.5 = 38.1 Metric Bolt. However, metric 38.1 is not available, therefore M38 to be used. But M38 is not exact equivalence.

Hello Vishal

The AI is a law unto himself. You would have to ask him. AI's are not required to check your calculations. They are required to verify that the calculations have been done. Vessels made in India are Code stamped, and I suppose they use metric bolts.

For standard flanges per ASME B16.5, use inch series boltings only irresptive of other dimensions OD, PCD etc which may be in metric version.

Most probably, AI will follow the Code.

Mukesh
www.theculminates.com
M: 91-9428500192

I suggest you check with the AI. I was an AI in South Africa (under South Africal regulations), and I accepted metric bolting. I generally felt the issue was too petty to loose any sleep over it.