Chris,
I think part of it is practicality. There are some situations where to get a 25% drop, you are going to have to drain the water tower. Also, with water companies that are doing their own tests with a couple of field guys, they are not going to open a bunch of hydrants; one and done. Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080 (tel:860-535-2080) (ofc) 860-554-7054 (tel:860-554-7054) (fax) 860-608-4559 (tel:860-608-4559) (cell) > > On Aug 30, 2022 at 5:21 PM, <Christopher Cahill > (mailto:[email protected])> wrote: > > > > > > Good day all, it’s been a while. I’m still here for you old timers. > > > > > > > > It appears the traditional 25% drop in residual pressure for satisfactory > results has been modified to 10%, ’22 edition 4.4.6. I’ve looked in the > committee reports and can’t find why. When I look in the enhanced content > on Link it talks about 25% still. So now I’m wondering if it’s a typo. > Anyone have an idea why this changed? > > > > > > > > The option to flow system demand appears modified as well in 4.4.7 When > conducting a flow test for the purpose of fire protection system design, the > flow and pressure results should be adequate for the total demand of the > system. Like that’s practical for high demand systems, lol. > > > > > > > > Putting it together does it all mean for fire flow drop 10% and for system > design we now HAVE to go to system demand? > > > > > > > > Chris Cahill, PE*\ Burns & McDonnell > > > > Sr. Associate Fire Protection Engineer > > > > Phone: 952.656.3652 > > > > [email protected] (mailto:[email protected]) > > > > > > > > *Registered in: MN > > > > > > > > > (https://www.burnsmcd.com/insightsnews/industries/construction?utm_campaign=CORP_NationalConstruction&utm_source=OutlookSignatures_Web-InsightsNews-Industry-Construction) > > > > > > > _________________________________________________________ SprinklerForum > mailing list: > https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org > To unsubscribe send an email to [email protected] >
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