Todd, Had a similar situation several years ago. This particular building had multiple design areas ranging from light to high piled storage. We decided we had to design to the no-pump supply data. Using your example of a 650 gpm sprinkler demand, what if only 75% of the design area sprinklers activated? That's a sprinkler flow of approx 488 gpm. If you design to the with-pump supply, you may or may not be getting the density you need. Difficult to predict since the actual delivered density increases with fewer sprinks activated.
At best, I think you lose some of the hidden safety factors normally built into the hydraulics. Now eat lots of turkey - THAT will put you to sleep! Ed Kramer Littleton, CO > > I did a flow test yesterday where the municipality had recently > installed a new variable speed pump at a pumping station. The static > pressure was 67 psi. We flowed the hydrant and the pressure dropped > to about 45 psi (flow of about 500 gpm). Then the pump kicked in and > boosted the pressure back up to 65 psi at a flow of about 750 gpm. > The system I am designing is a 13R, so which curve to use is obvious. > However, if the sprinkler system design required 650 gpm, should I > use the curve without the pump or include the new pump as the water > supply for the design? Prudence may dictate that you use the supply > without the pump, but what if now a pump would be required to meet > that demand? I know this is rhetorical, but I'm losing sleep...... > > Todd G. Williams, PE > Fire Protection Design/Consulting > Stonington, Connecticut > www.fpdc.com > 860.535.2080 _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [EMAIL PROTECTED] To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
