So this given time just poped up from the NFPA guy's head one day and then was written into code.thought any rules or requirment in NFPA must have a solid reason(apparent or compelling) behind them.
It says in NFPA 13 that the air supply shall have a capacity capable of restoring normal air pressure in the system within 30 minutes.So where does this "30-minutes" comes from?? is it a time interval relevant to the time of fire duration or this "30-minutes" just exists in this code for nothing?
