DonPhillips,
Georgia is one of them and has the most peculiar I've run across.
on page 25 Exception 2.
2. Delete 7.8.2.1 in its entirety and substitute in its place the following:
“7.8.2.1 Pipe schedule designed standpipe systems shall have piping sized in accordance with the pipe schedule in Table 7.8.2.1 to provide the required waterflow rate at a minimum residual pressure of 100 psi (6.9 bar) at the topmost 2-1/2 inch (65 mm) hose connection and 65 psi (4.5 bar) at the topmost 1-1/2 inch (38 mm) hose connection.
Exception No. 1: Where the local Fire Chief or local Fire Code Official having fire suppression jurisdiction permits lower than 100 psi (6.9 bar) for 2-1/2 inch (65 mm) hose connections, based upon local suppression tactics, the pressure shall be permitted to be reduced to not less than 65 psi (4.5 bar).
Exception No. 2: Where the building is protected thoughout by a supervised automatic sprinkler system and the building is not a high-rise, as defined in 3.3.9, the minimum residual pressure provisions shall not be mandatory when the standpipe system piping is a minimum of eight inches (8”) nominal diameter.
Exception No. 3: Existing high-rise buildings, as defined in 3.3.9, that are protected throughout by a supervised automatic sprinkler system shall be permitted a reduction of the minimum residual pressure requirement of 100 psi (6.9 bar) at the hydraulically most remote 2-1/2 inch (63.5 mm) hose connection to 65 psi (4.5 bar).”
I wish they would lower the 8" to 6" for standpipes or pipe feeding a single standpipe leaving everything else at 8". At 500 gpm through 8" the friction loss developed is near nothing but the change was well needed. Three and four story hotels all had to have fire pumps and the local authority required these to be diesel or be equipped with a generator backup/transfer switch etc which drove costs out of control. The number of 4 story motels with the top floor at 31' or 32' above lowest level of fire department access, requiring a $100,000 plus standpipe installation, is staggering.
This is just my opinion but I've always felt standpipes could get one into a lot of trouble dealing with standpipes because after sprinklers we view them as simple and easy. Not the case at all.
