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22" Class 600 Flange Stud Lengths

22" Class 600 Flange Stud Lengths

22" Class 600 Flange Stud Lengths

(OP)
In trying to calculate stud bolt lengths for an odd size 22" Class 600 B16.5 RF flange joint, I've run into an issue. These lengths are not published in B16.5 or by vendors that I've seen. B16.5 points you to use Nonmandatory App. C for stud bolt lengths in unpublished sizes. However, to follow the calc in this appendix one needs to know the minimum flange thickness & stud bolt diameter of the odd size. Since these values are not published either, how would one run this stud length calc?

Thanks

RE: 22" Class 600 Flange Stud Lengths

I can't see why you can't just look at the sequence in B 16.5 and iterate between the 20" flange and the 24" flange looking at how the sequence goes in the preceding sizes, i.e. fixed increase or increasing increase between sizes.

For bolt holes, 20 has 16 x 3 1/8 holes, 24" has 16 at 3 5/8". Bolts are 1/8" smaller diameter than the holes, so 22" would be 3 3/8" holes with 3 1/4" bolts.

Bolt circle diameter is then half way between 831 and 990, thickness 124mm etc, but if you take 130 you won't be too short.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: 22" Class 600 Flange Stud Lengths

Would someone please tell me how you can call something a B16.5 flange if the dimensions of that flange are not provided in B16.5? There is no NPS 22 size in either of Tables 15 or 16 (for Class 600 flanges).

Forget stud length, how are determining the pressure-temperature rating?

RE: 22" Class 600 Flange Stud Lengths

(OP)
I guess the title "Pipe Flanges & Flanged Fittings NPS 1/2 Through NPS 24" was enough for me. Unless you want to re-write & re-design an entirely new industry standard.

RE: 22" Class 600 Flange Stud Lengths

You will note that the NPS sizes provided in (for example) Tables 15 and 16 do not consider every possible size, but only the common sizes. Your NPS 22 size is not contained there.

So again, I ask, how will you determine the pressure-temperature rating of a flange that has no provided dimensions?

The title of B16.5 is accurate. It contains sizes NPS 1/2, a vast selection of intermediate sizes, and NPS 24.

RE: 22" Class 600 Flange Stud Lengths

This is an old obsolete size - 22"-600 would have 24 x 1.3/4" bolts, and flanges are 3.3/4" thick plus 1/4" r.f. height. Thus, assuming say 1/8" for a compressed spiral-wound gasket for example (another non-standard size item these days, not likely to be ex-stock), then you get 8.1/8" clamp length, allow just under 4" for two nuts and two threads through at each end makes 12.1/8" or more if you want to add washers as well of course.

RE: 22" Class 600 Flange Stud Lengths

They are not listed in B 16.5, but appear to be listed in MSS-SP-44 - http://www.zmcsteel.com/PDF/Flange/ANSI%20Flange/A... and track down to the class 600 flanges.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

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