The role velocity plays is that friction loss is proportional to the square of the velocity. Using Darcy-Weisbach this holds “truer” at any velocity than Hazen-Williams does outside a certain range of velocities. It’s interesting to calc using D-W with the weight density and viscosity of clean water at 40F and find the velocity producing the same friction loss as H-W for a particular pipe size and C-Factor. You should only try this at home nights and weekends though, as it can get pretty wild. I’ve heard that when the founders were coming up with the pipe schedules, they assumed a minimum end head pressure and spacing (to determine the flow), added the flows along the way, and increased the pipe size when the velocity got to around 32 ft/s.
b From: Bob Caputo <bcap...@firesprinkler.org> Sent: Tuesday, March 15, 2022 11:16 AM To: Byron Weisz <by...@cen-calfire.com>; Michael de Gabriele <mpdegabri...@gmail.com>; Sprinkler Academy - C Bilbo <prodesigngr...@msn.com> Cc: travis.m...@mfpdesign.com; sprinklerforum@lists.firesprinkler.org Subject: [Sprinklerforum] Re: [EXTERNAL] Re: Velocity - Rant Two separate issues: There is no safety margin required by NFPA standards with regard to the water supply test versus the system demand. The annex recommends one but the AHJ has the purview to require one. I have tried many times, to define a 10% or 5% required safety margin by submitting proposals to the NFPA 13 committee and none have passed. Ken Isman from University of Maryland (formerly from NFSA) also pushed this issue passionately but failed to convince the committee that a safety margin is required, or that one can e defined for every project. If your project is in the already populated area, you may not need one but if it’s a location where communities are being developed or factories and warehouses are being planned, 10% might not be enough. The evaluation of water supplies is engineering as opposed to design. A registered professional engineer should evaluate all of the issues surrounding a project to determine the adequacy of a water supply. NFPA standards provide wide leeway for the AHJ to make decisions, since they are the ones who need to show up and fight a fire or access a building. It is within the purview of the AHJ to add a safety margin to a water supply where they determine one is needed. The velocity issue is simple. NFPA standards do not require or limit velocities anywhere except for the suction side of a fire pump. NFPA 13 and 24 did limit velocities many years ago but the reasons have long since been dispelled. People though at faster velocities, the Hazen Williams formula was less accurate. Joe Hankins once told me that FM’s velocity limits were created because they didn’t want 1” grids or systems that couldn’t be upgraded as tenants or owners changed hands or building uses. The benefit of being old is knowing old stuff, as long as you can still remember it [https://www.dropbox.com/s/g4h8r7hdtsr6154/AFSA_L.png?raw=1] Bob Caputo, CFPS President American Fire Sprinkler Association c: 760-908-7753 p: 214-349-5965 ext124 w: firesprinkler.org<http://firesprinkler.org/> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/facebook_sig.png]<https://www.facebook.com/firesprinkler.org/> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/twitter_sig.png] <https://twitter.com/afsa/status/1039528345367732224> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/linkedin_sig.png] <https://www.linkedin.com/company/american-fire-sprinkler-association-afsa-/> [http://cdn2.hubspot.net/hubfs/184235/dev_images/signature_app/instagram_sig.png] <https://www.instagram.com/firesprinklerorg/> Expand your business with ITM. Professionalize the role of your inspection team with AFSA’s comprehensive 20-month ITM Inspector Development program<https://www.firesprinkler.org/itm> that provides a blended learning environment teamed with robust curriculum created by top industry leaders. Now enrolling for Spring 2022! From: Byron Weisz <by...@cen-calfire.com<mailto:by...@cen-calfire.com>> Sent: Tuesday, March 15, 2022 9:18 AM To: Michael de Gabriele <mpdegabri...@gmail.com<mailto:mpdegabri...@gmail.com>>; Sprinkler Academy - C Bilbo <prodesigngr...@msn.com<mailto:prodesigngr...@msn.com>> Cc: travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com>; sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] Re: [EXTERNAL] Re: Velocity - Rant I think there are some good practices that need to be followed in the design of fire sprinkler systems and sometimes “simpler” is better. Treating the flow of water in fire sprinkler piping to other mechanical systems are not comparable. The obvious is a fire sprinkler system is designed for emergency use and other mechanical systems are in continuous use. Sadly, most Mechanical Engineers who write specifications for fire sprinkler design don’t understand the difference. I was taught that velocity in fire sprinkler piping was irrelevant and to my knowledge there is nothing stated in NFPA 13. To continue the conversation there is no reference of a “safety margin” in NFPA 13 either. I was told many years ago by this guy named Bob Caputo that NFPA 13 allow you to design right to the design curve. Most jurisdictions in the Republic of California give water flow data from either the Fire Department or a Water Service Company to use for design of a system. This information is usually doctored in some way. So why would a designer take “doctored” water flow data and then include a 10% safety margin? Other than to meet a local requirement there is no reason. What makes no sense at all is to take “doctored” water flow information and use that information to size a fire pump to design an ESFR fire sprinkler system. Again, the best person to answer the questions of velocity and safety margin in the design of a fire sprinkler system gracefully would be Bob. Byron Weisz Cen-Cal Fire Systems, Inc. P.O. Box 1284 Lodi, CA 95241 Phone (209) 334-9119 Fax (209) 334-2923 Cell (209) 993-8832 by...@cen-calfire.com<mailto:by...@cen-calfire.com> This and any attached documents are for the use of the intended recipient(s) only and may contain information that is privileged, confidential, or work product that may be exempt from disclosure under applicable law. If you are not the intended recipient, any use, dissemination, distribution, or copying of this communication and any attachments is strictly prohibited, and you are hereby requested to delete this message and any attached documents, to destroy any printed copies, and to telephone or otherwise contact the sender immediately about the error. From: Michael de Gabriele <mpdegabri...@gmail.com<mailto:mpdegabri...@gmail.com>> Sent: Tuesday, March 15, 2022 5:46 AM To: Sprinkler Academy - C Bilbo <prodesigngr...@msn.com<mailto:prodesigngr...@msn.com>> Cc: travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com>; sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] Re: [EXTERNAL] Re: Velocity - Rant You don't often get email from mpdegabri...@gmail.com<mailto:mpdegabri...@gmail.com>. Learn why this is important<http://aka.ms/LearnAboutSenderIdentification> Hello All, I hope that this email finds you well. I practice fire protection in Australia, and recently the Australian standards have removed the requirements for maximum pipe work velocity in sprinkler systems. We also design systems to NFPA and FM Global requirements when insurers request upgrades, and as of late, the insurer on one particular project queried the pipe work velocities. I couldnt find any reference to velocity limitations in NFPA 13. I still try and keep my sprinkler pipe velocities down to a reasonable & practical value (6m/sec through valves and max. 10m/sec in pipe work as per the older/superseded code). I am curious though to whether the Hzen Williams Formula produces greater errors as the Velocities Increase in the pipe? Has anyone ever seen a limitation to the Formula or come across any articles to this effect? Looking forward to your response / comments / advice Kind Regards Michael de Gabriele Fire Protections Engineer mpdegabri...@gmail.com<mailto:mpdegabri...@gmail.com> On Tue, Mar 15, 2022 at 10:48 PM Sprinkler Academy - C Bilbo <prodesigngr...@msn.com<mailto:prodesigngr...@msn.com>> wrote: Hi Travis, I learned many years ago the reason velocity restrictions have persisted. In systems that have running water, the higher velocities wear the inner walls of the pipe/tube down over time. The limits were intended to bolster system lifetime. Mechanical engineers are the largest group responsible for specifying sprinkler systems and used the limits that seemed reasonable to them. Of course, our systems are not flowing or circulating and these rules should not apply to dedicated fire protection piping. We have only recently come away from having "closed loop circulating systems" being defined in the NFPA 13 Standard. And this is one of the reasons we used to do that. About the only requirement I have seen in Fire Protection was the old rules from FM Global (last 10-15 years) where the underground systems had limits. I believe those have been gone for a while. However, some MILSPEC and certain States still have some requirements embedded in older sections of regulations. Hope this helps. It should be recognized that the above is my opinion as a member of the NFPA, and has not been processed as a formal interpretation in accordance with the NFPA Regulations Governing Committee Projects and should therefore not be considered, nor relied upon, as the official position of the the NFPA, nor any of their technical committees. Sincerely, Cecil Bilbo Academy of Fire Sprinkler Technology Decatur, IL 217.607.0325 www.sprinkleracademy.com<http://www.sprinkleracademy.com> ce...@sprinkleracademy.com<mailto:ce...@sprinkleracademy.com> ?? OUR STUDENTS SAVE LIVES!! ________________________________ From: travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com> <travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com>> Sent: Monday, March 14, 2022 5:41 PM Cc: sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> <sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org>> Subject: [Sprinklerforum] Re: [EXTERNAL] Re: Velocity - Rant This was the “why” that I got: We require a 10 psi margin for safety and to account for future degradation of water supply. The 14 fps insures that the piping will be larger and is an added layer of margin for future development. It wasn’t a fight the contractor wanted to go with since it was something he missed in the specs. They had no explanation as to why 14 fps. Please rate our customer service<https://survey.medallia.com/?emailsignature&fc=3539&bg=Fire%20and%20Fabrication> Travis Mack, CFPS, CWBSP, RME-G, COC, SET Senior Engineering Manager MFP Design 480-505-9271 ext. 700 C: 480-272-2471 travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com> www.mfpdesign.com<http://www.mfpdesign.com> Send large files to us via: https://www.hightail.com/u/MFPDesign<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.hightail.com%2Fu%2FMFPDesign&data=02%7C01%7C%7C1121d49f9e6b4cf248f108d4df580e77%7C14e5497c16da42e69ffa77d19bafe511%7C0%7C0%7C636379016677342180&sdata=eGdMZGu2wXhUupGwgGTrqF3b54OP5%2BAZvlHhABSexWY%3D&reserved=0> From: Ken Wagoner <k...@parsleyconsulting.com<mailto:k...@parsleyconsulting.com>> Sent: Monday, March 14, 2022 3:36 PM To: Travis Mack <travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com>> Cc: sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: Re: [Sprinklerforum] Re: [EXTERNAL] Re: Velocity - Rant Travis, I've run up against that a time or two myself. It honestly baffles me how those who have so limited an understanding of fire sprinkler systems mandate what we do. I've usually responded in one of several ways. 1st, I ask them to show me where in any applicable code or standard they've found a limitation on velocities in above ground piping. And, clearly, as you and others have said - they can't because it isn't there. As far as NFPA is concerned it never was. A contact I had at NFPA a few years back told me of an "engineer" who called him and wanted to know when that had been removed from -13. He did some research and found that it was never removed, because it was never there in the first place. That didn't go over well with the caller who was sure my contact was misleading him. 2nd, I acknowledge that the limitations on velocities in underground pipes on public property are established as another poster observe to lessen the deterioration caused from perpetually flowing water. When I mention that pipe sizing on public property is their purview, and what is installed on private property they have no control over. Usually my trump card in that argument is to ask why backflow preventers are usually at or near the property line. 3rd, and this works almost every time, I ask them to explain "why". I don't hear many responses to that which make any sense as far as fire sprinklers go. my thoughts only, Ken Wagoner, SET Parsley Consulting 500 West Mechanic Street Harrisonville, Missouri 64701-2235 Phone: (760) 745-6181 Visit the website<https://linkprotect.cudasvc.com/url?a=http%3a%2f%2fwww.parsleyconsulting.com%2f&c=E,1,Y5zKJKPEh1mBEBqSR-VE9cUKl5y-eyP8BpvmE_5j9ZqW2eJbNphYzrCMBZ-2YuX6d-RRkHI4gQ1FV-cvOeCfRC58uZS9NiToZv2mx7909oCqLvCW_n5hDHeK&typo=1> On 3/14/2022 3:33 PM, travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com> wrote: I totally realize where all this comes from. It just amazes me at times, how long incorrect information and lack of understanding of things can remain in an industry. I always challenge anyone to show me in a copy of NFPA 13 anytime where it had velocity limits. I’ve checked back as far as the 30’s and could never find it. People always say, I know it was in there at one time. Please rate our customer service<https://survey.medallia.com/?emailsignature&fc=3539&bg=Fire%20and%20Fabrication> Travis Mack, CFPS, CWBSP, RME-G, COC, SET Senior Engineering Manager MFP Design 480-505-9271 ext. 700 C: 480-272-2471 travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com> www.mfpdesign.com<http://www.mfpdesign.com> Send large files to us via: https://www.hightail.com/u/MFPDesign<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.hightail.com%2Fu%2FMFPDesign&data=02%7C01%7C%7C1121d49f9e6b4cf248f108d4df580e77%7C14e5497c16da42e69ffa77d19bafe511%7C0%7C0%7C636379016677342180&sdata=eGdMZGu2wXhUupGwgGTrqF3b54OP5%2BAZvlHhABSexWY%3D&reserved=0> From: Prahl, Craig/GVL <craig.pr...@jacobs.com><mailto:craig.pr...@jacobs.com> Sent: Monday, March 14, 2022 1:30 PM To: Brett Peters <br...@proudline.ca><mailto:br...@proudline.ca>; Travis Mack <travis.m...@mfpdesign.com><mailto:travis.m...@mfpdesign.com> Cc: sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: RE: [EXTERNAL] [Sprinklerforum] Re: Velocity - Rant What Brett said. I have had more “discussions” on velocity and pressure loss where the challenger was quoting limits that are placed on totally unrelated type systems. Try to explain to them that those rules do not apply to fire protection systems and they’ll look at you like you’ve got a horn coming out of your forehead. I’ve also had these types of artificial limitations placed by owners who have some “FP” person on staff who has never performed a flow test or developed a hydraulic calculation but did stay at a Holiday Inn Express which had sprinklers. Craig Prahl | Jacobs | Group Lead/SME – Fire Protection | craig.pr...@jacobs.com<mailto:craig.pr...@jacobs.com> | www.jacobs.com<http://www.jacobs.com/> 1041 East Butler Road Greenville, South Carolina 29606 CONTACT BY: email or MS TEAMS From: Brett Peters <br...@proudline.ca<mailto:br...@proudline.ca>> Sent: Monday, March 14, 2022 4:13 PM To: travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com> Cc: sprinklerforum@lists.firesprinkler.org<mailto:sprinklerforum@lists.firesprinkler.org> Subject: [EXTERNAL] [Sprinklerforum] Re: Velocity - Rant It's because they have velocity limits when sizing heating and water lines and can't wrap their heads around sprinkler hydraulics. when you have constant water flow through piping, high velocity wears the pipe out faster, somehow they translate that to sprinkler pipe failure even though sprinkler pipe rarely even sees any water flow! Thanks Brett Peters General Manager Installation & Design Proudline Fire Protection Services Ltd. br...@proudline.ca<mailto:br...@proudline.ca> 780 490 7602 office ext 202 780 490 7605 fax 780 777 0568 cell 780 718 2676 24h Visit us at www.proudline.ca<https://urldefense.com/v3/__http:/www.proudline.ca/__;!!B5cixuoO7ltTeg!XuefiEhzuSpMkE5hwQfrMaq2esN89q-FRGseCr912x9x3M0x79mcWA0V05NMb4e_4w$> [https://drive.google.com/uc?id=1OmoSKJ_6j8bUkKaO7Bn03FqLsLL_CGFg&export=download] [https://drive.google.com/uc?id=12vmay3NIMK7kvNSKzKSwQ3QMUu4c0Pjh&export=download] [https://drive.google.com/uc?id=1WooQGP1U-Z-tivGaOd9iUIJe1t5nDIjs&export=download] [https://drive.google.com/uc?id=1MBUQypGGoakyf2Oz-f89so4CO5gWL-XH&export=download] [https://drive.google.com/uc?id=1-auFTtN-brybbHNv2RnkM0NRf831e6rW&export=download] [https://drive.google.com/uc?id=14_f6c1uVNDgMx_0OrApPsa-zCV1WCOMO&export=download] [https://drive.google.com/uc?id=1kQhWctmizXAVYEesipCzOmZj6rp3W5J7&export=download] [https://drive.google.com/uc?id=1cLsq8r4z61yUMJBu7OB2THA3zKwD16X4&export=download] On Mon, Mar 14, 2022 at 1:50 PM <travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com>> wrote: Does anyone have any idea where these engineers come up with the velocity limits? We have one that they are requiring a 10 PSI margin (not an issue since AHJ requires 20%), but also limiting velocity to FOURTEEN fps. There has never been a limit in NFPA 13. The velocity that we determine is only based on a demand calc. The water supply doesn’t know to reduce flow so that a 10 psi margin is maintained. If a single sprinkler activates, that 1” arm over is going to see far greater than 14 fps. It really just baffles me how this criteria has become so ingrained in the engineering culture. Please rate our customer service<https://urldefense.com/v3/__https:/survey.medallia.com/?emailsignature&fc=3539&bg=Fire*20and*20Fabrication__;JSU!!B5cixuoO7ltTeg!XuefiEhzuSpMkE5hwQfrMaq2esN89q-FRGseCr912x9x3M0x79mcWA0V05PqkrhoUQ$> Travis Mack, CFPS, CWBSP, RME-G, COC, SET Senior Engineering Manager MFP Design 480-505-9271 ext. 700 C: 480-272-2471 travis.m...@mfpdesign.com<mailto:travis.m...@mfpdesign.com> www.mfpdesign.com<https://urldefense.com/v3/__http:/www.mfpdesign.com__;!!B5cixuoO7ltTeg!XuefiEhzuSpMkE5hwQfrMaq2esN89q-FRGseCr912x9x3M0x79mcWA0V05Muei1aEQ$> Send large files to us via: https://www.hightail.com/u/MFPDesign<https://urldefense.com/v3/__https:/na01.safelinks.protection.outlook.com/?url=https*3A*2F*2Fwww.hightail.com*2Fu*2FMFPDesign&data=02*7C01*7C*7C1121d49f9e6b4cf248f108d4df580e77*7C14e5497c16da42e69ffa77d19bafe511*7C0*7C0*7C636379016677342180&sdata=eGdMZGu2wXhUupGwgGTrqF3b54OP5*2BAZvlHhABSexWY*3D&reserved=0__;JSUlJSUlJSUlJSUlJSU!!B5cixuoO7ltTeg!XuefiEhzuSpMkE5hwQfrMaq2esN89q-FRGseCr912x9x3M0x79mcWA0V05Mmw_OSKQ$> SprinklerForum mailing list Sprinklerforum@lists.firesprinkler.org<mailto:Sprinklerforum@lists.firesprinkler.org> https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://urldefense.com/v3/__https:/lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org__;!!B5cixuoO7ltTeg!XuefiEhzuSpMkE5hwQfrMaq2esN89q-FRGseCr912x9x3M0x79mcWA0V05Pso7LieA$> ________________________________ NOTICE - This communication may contain confidential and privileged information that is for the sole use of the intended recipient. Any viewing, copying or distribution of, or reliance on this message by unintended recipients is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer. _________________________________________________________ SprinklerForum mailing list Sprinklerforum@lists.firesprinkler.org<mailto:Sprinklerforum@lists.firesprinkler.org> https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org [https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png]<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Virus-free. www.avg.com<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> _________________________________________________________ SprinklerForum mailing list Sprinklerforum@lists.firesprinkler.org<mailto:Sprinklerforum@lists.firesprinkler.org> https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org
_________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org
