Pipe seismic braces - ASME B31 ref. in ASCE 7

[JAE]

According to ASCE 7 - in the seismic section for design of Mechanical and Electrical Components (see table 13.6-1 ASCE 7-10 or in ASCE 7-05)
there is a qualifier in the table that affects our seismic design.

This qualifier states that the Rp and ap values to be used depend on whether the piping system conforms to ASME B31.

Does anyone know what B31 requires relative to the pipes? We are structural engineers and aren't familiar with B31 and our
client also doesn't seem to know...which suggests that we should presume that the piping isn't designed per B31 - but
thought I'd ask.

Thanks.

 

[ATSE]

My mechanical engineer friends explain to me that the robust connection requirements of ASME B31 provide for a ductile system, compared to welded / threaded/ coupled end systems without the same requirements. Sounds about right.
I think the difference you're referring to is R = 12 vs. 9, and R = 6 vs. 4.5.
I would use the lower values (9 and 4.5) unless there was a mandate to do otherwise.
How the R and Rp values were arrived upon seems to be part reason, part historical experience, part lobbying from trade groups, part voodoo.

 

[JAE]

Does B31 have info on the structural hanging and bracing of pipes? Or is it just involved with the pipes themselves?