Hi Steven, I don’t believe NFPA 13, 2007 will allow this. In the commentary section it says the following concerning DIPA’s:
“The restriction stipulated in 7.2.3.10 does not apply to a preaction system, unless it is of the double interlock type. These types of preaction systems maintain air pressures typical of those of dry pipe systems and should be treated as such. The use of a looped piping arrangement is not prohibited for a dry pipe system, because the associated water delivery time delays are not as severe as for a gridded system.” Best regards, Mike Stossel NICET Level IV Automatic Sprinkler System Layout 1070 38th Street Brooklyn N.Y. 11219 Office: 718-633-3036 ext 114 Fax: 718-633-4593 [email protected]<mailto:[email protected]> www.safetyfiresprinkler.com<mailto:[email protected]> From: Sprinklerforum [mailto:[email protected]] On Behalf Of Steve Mackinnon Sent: Wednesday, June 08, 2016 1:44 PM To: [email protected] Subject: gridded pipe in a DIPA system Just came across a set of fire sprinkler plans for a freezer… The engineer wants to install a DIPA with gridded pipe, would this arrangement be allowed by NFPA 13, 2007 standards?? I know the good book says a DIPA system is considered a dry system for the 30% design area increase, but what about “gridding of pipe”? A DIPA system would only have supervisor air… wouldn’t this help the water reach the open sprinkler heads similar to a wet system? Thank you Steven
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