Cross Code Question - Supports

Alright - a question for the code experts. In B31.3, 321.3.1 Nonintegral Attachments makes it pretty clear that it is prefered that a support, such as a U-bolt on a vertical pipe, not rely on friction as the basis for the support. A lug, flange, etc. if recommended to provide a positive transfer of the load from the pipe to the support structure.

I'm giving general feedback on some vendor boiler piping being done to ASME B&PV Code Section 1. I would assume as a matter of common sense that this code and the B31.1 code would have a similar admonition to the designer, but I'm not familiar enough with them to find such a reference.

Can any of the code experts help me with a direction? I try to avoid dealing with the B&PV code as much as possible

Thanks,

Hi Ed,

The boiler external piping is B31.1 so all the B31.1 rules (e.g., 121.8.1(B) et. al.) apply for technical responsibility. Inside the boiler it is all ASME Section I but common sense in design still applies - if that Code is silent you can still appeal to common sense. I am pretty sure no Code says you can’t do the right thing.

Regards, John.

Ed,

B31.1 as always is more proscriptive check out note C!!! ....

121.8.1 Nonintegral Type
(A) Nonintegral attachments include clamps,
cradles, saddles, straps, and clevises.
(B) When clamps are used to support vertical
it is recommended that shear lugs be welded
to prevent slippage. The provisions of para.
shall apply.
(C) In addition to the provision of (B) above,
to support vertical lines should be designed
the total load on either arm in the event the
due to pipe and/or hanger movement.

Good practice and in writing although we see the non-mandatory word recommended and not shall!!!

Thanks gentlemen. I did call for a positive restraint as it is definitely the right thing to do.

I would have appealed to B31.3 as a reference if nothing else. But, with that direct reference in B31.1, I now have a directly applicable citation in case the vendor wants to challenge.

The moral of the story - don't try to slip a u-bolt support past me w/o a lug!