Has there even been a generally accepted correlation of a main drain test to a hydrant flow test? (Except static pressure). 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 Sep 11, 2024 at 2:14 PM, <Chris Dorn > (mailto:[email protected])> wrote: > > > > > > What C factor did you use for your underground piping? If the piping is old > enough that it is not enamalined or internally coated ductile iron l then you > should be using a c factor of no better than a 100 not 140. If there is > significant corrosion in the underground then you may want to use an even > worse C factor of 80. There could be build up in the underground piping that > is restricting the flow and causing additional pressure loss through the > underground line that you are not accounting for. Just a thought. > > > > Chris > > > > > > > > > > > > > > From: Kyle.Montgomery <[email protected]> > Sent: Wednesday, September 11, 2024 1:55 PM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected]> > Subject: [Sprinklerforum] Re: [External]Re: main drain test > > > > > > > > > > That’s how much you SHOULD have, or that’s how much you MUST have. Add the > demand (pressure required) and your safety margin to figure out your expected > pressure. > > > > > > > > If you’re starting with 87 psi and losing 29 psi for backflow and elevation, > that leaves 58 psi. At 361 GPM, your 6” pipe should only be losing about 0.5 > psi per 100 feet of pipe. So, you should probably be expecting more than 50 > psi at your main drain if flowing the system demand (obviously I’m guessing > at the configuration of your system). But even if you are actually flowing > 750 GPM through your main drain test, 6” pipe only loses about 1.6 psi per > 100 feet of pipe. > > > > > > > > I think the inspector might be onto something. That 37 psi doesn’t seem to > jive. > > > > > > > > -Kyle M > > > > > > > > > > From: Rocci 3 Cetani <[email protected] (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 10:41 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [Sprinklerforum] Re: [External]Re: main drain test > > > > > > > > > > We lose 12 PSI for the backflow, a little more than 17 PSI for elevation. > The calc says we should have about 45.5 PSI @ BOR on the 4th floor > > > > > > > > > Rocci Cetani III, CET > > > > Senior Designer > > > > Water-Based Fire Protections Systems Layout, Nicet Level III > > > > > > > > > > > > Northern California Fire Protection Services Inc. > > > > 16840 Joleen Way Bldg. A > > > > Morgan Hill, CA 95037 > > > > P-(408) 776-1580 EXT.1010 > > > > F-(408) 776-1590 > > > > > > > > To help better serve you. Please visit our new and improved website at: > > > > www.norcalfire.com (http://www.norcalfire.com/) > > > > > > > > CONFIDENTIALITY NOTICE: This message and any document accompanying it may > contain confidential information belonging to the sender. The information is > intended only for the use of individual or entity named above. If you are not > the intended recipient, or the employee or agent responsible to deliver this > message to the intended recipient, you are hereby notified that any > disclosure, copying or taking of any action in reliance on the contents of > this information is strictly prohibited. If you have received this > transmission in error, please immediately notify us by telephone to arrange > for return of the documents. > > > > > > > > > > > From: Kyle.Montgomery <[email protected] > (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 10:03 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [Sprinklerforum] Re: [External]Re: main drain test > > > > > > > > > > From your previous reply: 6” feed in the stairwell with a 4” sectional and > 2” drain > > > > > > > > Residual pressure is dropping 50 psi from the flow test to what you are > seeing on the gauge in your main drain test. Flowing 361 GPM through 6” and > some 4”? Even accounting for elevation pressure at the 4th floor, that seems > like a LOT of pressure loss. Does that number make sense. > > > > > > > > When you run your calc what pressure do you expect to have at the base of > riser? You said the required pressure is 45 psi, so add your safety margin to > that and tell me what you expect to have. > > > > > > > > -Kyle M > > > > > > > > > > From: Rocci 3 Cetani <[email protected] (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 9:54 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [External][Sprinklerforum] Re: main drain test > > > > > > > > > > MDT > > > > Static 62 (auto sprink says it should be 63.2 so its within a comfortable > range) > > > > Residual- 37 > > > > > > > > Flow test > > > > Static 89 > > > > Residual 87 > > > > GPM 750 > > > > > Rocci Cetani III, CET > > > > Senior Designer > > > > Water-Based Fire Protections Systems Layout, Nicet Level III > > > > > > > > > > > > Northern California Fire Protection Services Inc. > > > > 16840 Joleen Way Bldg. A > > > > Morgan Hill, CA 95037 > > > > P-(408) 776-1580 EXT.1010 > > > > F-(408) 776-1590 > > > > > > > > To help better serve you. Please visit our new and improved website at: > > > > www.norcalfire.com > (https://urldefense.proofpoint.com/v2/url?u=http-3A__www.norcalfire.com_&d=DwMFIw&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=hLXh1DXRDwJ3oz4y7iNesSsetYhUUV0wawfPGfwmYxQ&m=rjklku6TtnAsbkPAj0Ah9-6LzYkNBBee_Sg6UuXdYXmvRgQlJf4mKyA8eedysC5Q&s=FM5eVjZHgu24BkVkFLo76rDJOoTdYKlfL7O8cgDGBgo&e=) > > > > > > > > CONFIDENTIALITY NOTICE: This message and any document accompanying it may > contain confidential information belonging to the sender. The information is > intended only for the use of individual or entity named above. If you are not > the intended recipient, or the employee or agent responsible to deliver this > message to the intended recipient, you are hereby notified that any > disclosure, copying or taking of any action in reliance on the contents of > this information is strictly prohibited. If you have received this > transmission in error, please immediately notify us by telephone to arrange > for return of the documents. > > > > > > > > > > > From: Steve Leyton <[email protected] > (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 9:33 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [Sprinklerforum] Re: main drain test > > > > > > > > > > Sorry, I misstated something extremely important: I referred to residual > pressure instead of PITOT pressure in my mention of theoretical flows. > Management regrets the error and the committee has authorized a second cup of > coffee. > > > > > > > > Steve L. > > > > > > > > > > > > > > From: Steve Leyton > Sent: Wednesday, September 11, 2024 9:25 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: RE: [Sprinklerforum] Re: main drain test > > > > > > > > > > Respectfully disagree that this is a slam-dunk misunderstanding. I have > experienced two residual-pressure-at-BOR conflicts in my career and both went > back to the water supply data. One of them had to do with a flow test > that was taken from the address-side public main, but the system was supplied > from a side street and it turned out that the POC was downstream of a > regulating station installed at the branch to that leg of the system, so > available pressure was 20 psi lower than the test data. The other had to > do with a flow test taken by a third party contractor hired by the project > owner, and they used an old riser gauge on the hydrant. Turns out that > gauge was shot and the residual value was corrupt (reading high). When > the water supply was tested again, the flow rate was nearly identical but the > residual was 8 or 9 or 10 psi lower using a calibrated gauge with ÷1% error. > As Chris noted, residual of 9-10 psi renders a theoretical flow > equivalent to the demand through a 2” orifice per NFPA 291, Table 4.12.1(a), > so the AHJ might be onto something. > > > > > > > > What is are the static and residual readings on the riser gauge during the > MDT, and what were the flow test values? And memo to everyone citing NFPA > 25, it is a requirement of NFPA 13, ∽29.2.3.4 that a main drain test be > undertaken as part of acceptance testing. > > > > > > > > > > > > Steve L. > > > > > > > > > > From: Travis Mack <[email protected] (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 8:24 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [Sprinklerforum] Re: main drain test > > > > > > > > > > > A main drain test does not correlate to a BOR demand. You have to flow the > exact same demand to make them correlate. So just educate the inspector. > This happens all the time in residential systems. > > > > > > > > > > > > > > > > Travis Mack, SET > > > > M.E.P.CAD| Instructor / Support > > > > 181 N. Arroyo Grande Blvd. #105 I Henderson, NV 89074 > > > > www.mepcad.com > (https://urldefense.proofpoint.com/v2/url?u=http-3A__www.mepcad.com_&d=DwMGaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=hLXh1DXRDwJ3oz4y7iNesSsetYhUUV0wawfPGfwmYxQ&m=ak88D-Fbuok5cqKxOL10fhK7rcEnUaYjg1aoYAJsRALJc0o65sBATxsNQhgr3Ej7&s=Arl_dm6gvc2m17hVq2LdbEtEDah-b7aM-wnbe-D3AYs&e=) > | m: 480.547.9348| Whatspp: +14805479348 > > > > Email: [email protected] (mailto:[email protected]) > > > > > > > > AutoSPRINK | AutoSPRINK FAB | AutoSPRINK RVT | > AlarmCAD > > > > > > > > > > > > From: Rocci 3 Cetani <[email protected] > (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 8:07 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [Sprinklerforum] Re: main drain test > > > > > > > > > > > > > > > > > Demand is 361 gpm with 45 PSI @ BOR. Main drain test they are getting 37 > residual > > > > > Rocci Cetani III, CET > > > > Senior Designer > > > > Water-Based Fire Protections Systems Layout, Nicet Level III > > > > > > > > > > > > Northern California Fire Protection Services Inc. > > > > 16840 Joleen Way Bldg. A > > > > Morgan Hill, CA 95037 > > > > P-(408) 776-1580 EXT.1010 > > > > F-(408) 776-1590 > > > > > > > > To help better serve you. Please visit our new and improved website at: > > > > www.norcalfire.com > (https://urldefense.proofpoint.com/v2/url?u=http-3A__www.norcalfire.com_&d=DwMGaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=hLXh1DXRDwJ3oz4y7iNesSsetYhUUV0wawfPGfwmYxQ&m=ak88D-Fbuok5cqKxOL10fhK7rcEnUaYjg1aoYAJsRALJc0o65sBATxsNQhgr3Ej7&s=-fKDxPy7MHNO47roQeJIyEkbYU5O6fDF5MByTDMROa0&e=) > > > > > > > > CONFIDENTIALITY NOTICE: This message and any document accompanying it may > contain confidential information belonging to the sender. The information is > intended only for the use of individual or entity named above. If you are not > the intended recipient, or the employee or agent responsible to deliver this > message to the intended recipient, you are hereby notified that any > disclosure, copying or taking of any action in reliance on the contents of > this information is strictly prohibited. If you have received this > transmission in error, please immediately notify us by telephone to arrange > for return of the documents. > > > > > > > > > > > From: Steve Leyton <[email protected] > (mailto:[email protected])> > Sent: Wednesday, September 11, 2024 7:55 AM > To: Discussion list on issues relating to automatic fire sprinklers > <[email protected] > (mailto:[email protected])> > Subject: [Sprinklerforum] Re: main drain test > > > > > > > > > > > Assuming that the demand from the calc area is for OH 1or 2 (and no inside > hose), your demand is somewhere between 250 and 300 gpm If you modeled a full > 1,500 sq ft, no? And what is the residual pressure required? > > > > > > > > > > > > > > > > > > > Steve Leyton > > > > > > > > > > > > Sent from my "Smart" Phone, so apologies for any typos or voice-to-text > corruptions. > > > > > > > > > > > > > > > > > > > > > > > > > -------- Original message -------- > > > > > > From: Rocci 3 Cetani <[email protected] (mailto:[email protected])> > > > > > > Date: 9/11/24 7:19 AM (GMT-08:00) > > > > > > To: [email protected] > (mailto:[email protected]) > > > > > > Subject: [Sprinklerforum] main drain test > > > > > > > > > > > > > We have a jurisdiction that failed our final inspection because the residual > pressure during the main drain test doesn’t match our BOR residual pressure > from the hydraulic calcs for and OH extended coverage system. Am I missing > something? I don’t see how the residual pressure on a main drain test has > anything to do with the residual pressure from our calcsˇ..I was always > under the impression main drain tests were to verify there hasn’t been a been > a drastic change to the supply . This was an existing parking garage where > they added solar panels on the top level so we added a sectional riser @ the > top floor and added the new system. The fire department just keeps saying to > upsize the riser from the 1st floor to the 4th floor which literally does > nothing to my calcs. The building owner has spent 10’s of thousands of > dollars flushing the UG, inspecting the UG for obstructions, paid for > additional flow test and serviced the back flow. We are at a complete > loss on what else to do as the fire department is adamant that’s the main > drain test has to match the hydraulic calcsˇ..anyone ever come across a > situation like this with a jurisdiction? Any suggestions? > > > > > > > > Rocci Cetani III > > > > > > > > Northern California Fire Protection Services Inc. > > > > 16840 Joleen Way Bldg. A > > > > Morgan Hill, CA 95037 > > > > P-(408) 776-1580 EXT.1010 > > > > F-(408) 776-1590 > > > > > > > > To help better serve you. Please visit our new and improved website at: > > > > www.norcalfire.com > (https://urldefense.proofpoint.com/v2/url?u=http-3A__www.norcalfire.com_&d=DwMF-g&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=hLXh1DXRDwJ3oz4y7iNesSsetYhUUV0wawfPGfwmYxQ&m=nP9h2h456PibjSYltHaC089-TD3Bl1n84A4GQG7tGUQxwsm_cBAuUH6N7llEvqY5&s=vKbW_TH-HMqG118ScSYZUkjK0Jxq_IycjhdQf3X2Le0&e=) > > > > > > > > CONFIDENTIALITY NOTICE: This message and any document accompanying it may > contain confidential information belonging to the sender. The information is > intended only for the use of individual or entity named above. If you are not > the intended recipient, or the employee or agent responsible to deliver this > message to the intended recipient, you are hereby notified that any > disclosure, copying or taking of any action in reliance on the contents of > this information is strictly prohibited. If you have received this > transmission in error, please immediately notify us by telephone to arrange > for return of the documents. > > > > > > > > > > > _________________________________________________________ SprinklerForum > mailing list: > https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org > To unsubscribe send an email to [email protected] >
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