UCS-11(c) and (d)

[pperlich]

I asked this question in the ASME forum, but didn't receive a response.
Is it permissible to use regular hex nuts (in lieu of heavy hex nuts) with UG-44 flanges in accordance with UCS-11(d)?
Thanks in advance!

 

[metengr]

(c) Nuts shall be semifinished, chamfered, and trimmed.
Nuts shall be threaded to Class 2B or finer tolerances according
to ASME B1.1. For use with flanges conforming
to the standards listed in UG-44, nuts shall conform at
least to the dimensions given in ASME B18.2.2 for Heavy
Series nuts. For use with connections designed in accordance
with the rules in Mandatory Appendix 2, nuts may
be of the ANSI Heavy Series, or they may be of other dimensions
as permitted in (d) below.
(d)Nuts of special design or of dimensions other than
ANSI Heavy Series may be used provided their strength
is equal to that of the bolting, giving due consideration
to bolt hole clearance, bearing area, thread form and class
of fit, thread shear, and radial thrust from threads [see
U-2(g)].

Yes, provided you meet (d) above.

 

[pperlich]

Thank you, metengr!
My concern was that the phase in (c):
"For use with flanges conforming to the standards listed in UG-44, nuts shall conform at least to the dimensions given in ASME B18.2.2 for Heavy Series nuts."
prohibited using (d) to justify smaller regular hex nuts. And then there is Table 1C of ASME B16.5.
But I agree that UCS-11(d) allows use of regular hex nuts provided a calculation shows that they are acceptable. Just wanted to make sure I wasn't the only one in the world that saw it that way.