I don't have my UL199 in front of me so I speak from recollection. It's an average thing and a minimum per plate thing I would guess. They actually put 1' square plates down to catch the water when doing the density testing. My guess out at the 20' mark it's hard to get the minimum for a 0.1 density but they make the minimum for 0.05. The minimums are much less than the required average of 0.1 or 0.05. So for every place that gets 0.2 some other pan is allowed to get 0.05 for a 0.1 test. Average is met in the test. If the minimum is 1/2 you are listed. I don't recall the minimums.
So at 18'6" mark with the same amount of water flowing you have the average of 0.1 and the minimum in all pans for 0.1. To get to the full 20' you need at least 2.4 more gpm just to cover the extra 24 sq.ft. (1.5*16). And it would have to land in the right pans. Chris Cahill, P.E. Fire Protection Engineer Sentry Fire Protection, Inc. 763-658-4483 763-658-4921 fax Email: [email protected] Mail: P.O. Box 69 Waverly, MN 55390 Location: 4439 Hwy 12 SW Waverly, MN 55390 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Todd Williams Sent: Tuesday, December 08, 2009 9:38 AM To: [email protected] Subject: 13 residential sidewalls I am reviewing a set of plans where the designer used residential sidewall sprinklers in 13 system (6 story apartment bldg). A particular room is 18'6 x 12' and he has a sidewall throwing the 18'6 and centered on the 12 ft wall. Since we have to use a 0.10 density, he based his design on 11.2.3.5.2. The listing for the sprinkler at the 0.05 density (16 x 20 sp) is 22 gpm at 27.4 psi. If we use the 0.10 density times the area as described per 8.5.2.1 (comment (2) in 11.2.3.5.2), we get 22.2 gpm at 27.9 psi. How can we expect to get twice the density at a an 18.5 ft distance out of the same flow and pressure by decreasing the width of a room? Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2 _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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)
