Seismic Bracing
Seismic Bracing
(OP)
AHJ wants seismic bracing per code, but says there must be bracing within 2 feet of every 90. The old school general rule is... ends, bends and change of direction need seismic bracing. When reading through Chapter 9, I do not see where it says bracing within 2' of changes in direction. Is this an old rule or is it somewhere in the code I am not seeing.





RE: Seismic Bracing
RE: Seismic Bracing
Strictly per NFPA 13, I don't believe the 2' from a turn is required if you are not using that same brace as a longitudinal for the adjacent pipe.
However, that old method of 40/80 and 4 way at change in direction, etc... that is long gone. Braces must be calculated. You have to meet specific requirements of the bracing components and for laterals, you have to take into consideration the size and schedule of the piping.
If you have not done bracing in a long time, you may want to spend a few hours in Chap 9 getting reacquainted. It is quite different.
Travis Mack
MFP Design, LLC
www.mfpdesign.com