PSI at top of standpipe
PSI at top of standpipe
(OP)
NFPA 14 (2000ed) Chapter 5-7(1) Exception No. 1 allows the AHJ to permit a hydraulically calculated standpipe to provide 65PSI at the top (rather than 100psi). Fine.
BUT... Exception No. 2 starts off: In other than high rise buildings...
Does anyone know why Exception No. 1 would NOT be allowed in high rise buildings??
Especially since, in a large city with full-time personel and pumper trucks, the Fire Department will pressurize the (in this case a class I) standpipe to whatever they want anyway. It almost makes the PSI at the top redundant because a class I standpipe is for F.D. use only anyway.
Any thoughts??
BUT... Exception No. 2 starts off: In other than high rise buildings...
Does anyone know why Exception No. 1 would NOT be allowed in high rise buildings??
Especially since, in a large city with full-time personel and pumper trucks, the Fire Department will pressurize the (in this case a class I) standpipe to whatever they want anyway. It almost makes the PSI at the top redundant because a class I standpipe is for F.D. use only anyway.
Any thoughts??





RE: PSI at top of standpipe
RE: PSI at top of standpipe
Yes, I also understand that the exceptions are not included in NFPA 2003. I believe it has to do with the difference between the smooth bore nozles and combination fog nozzles that are use in some City Departments but not others. But, that's an entirely different matter.
RE: PSI at top of standpipe
I worked on a project where we could hardly stay under the 175 max on the lower piping and meet 65 at the top.
Ken