NFPA 13 (2016) Section 9.2.5.3 is Section 17.4.5.3 in the 2022 edition. All my references below are from 2022.
Horizontally installed ATR can prevent pipe from tipping away from the wall but cannot support pipe weight in the direction of gravity in any orientation other than as follows which correlates with the prohibition using ATR where bending moments are induced per Section 17.2.1.6: 1. Axial tension per Sections 17.2.1.3 and 17.4.5.3 further clarified in Sections A.17.2.1.3(1) and A.17.4.5.3. An example of this is the ATR in all the hangers shown in Figure A.17.2.1.3(1) are loaded in axial tension. 2. Use in axial compression is limited to sway bracing based on L/R selection per Tables 18.5.11.8. This eliminates use of ATR as a component in most pipe stands. The following are my opinions based on my understanding of NFPA 13: 1. Except where loads are less than or equal to the loads indicated in Tables 18.5.11.8, loading ATR non-axially and not in tension induces shear forces, or the potential thereof, for which ATR is not designed to withstand...except to add another hanger configured as shown in Figure A.17.2.1.3(1). 2. Support of vertical piping sections must use a configuration of angle brackets properly fastened to the wall in conjunction with pipe clamps attached to the pipe clamps or some other equivalent configuration where ATR is not in bending or shear. 3. Spacing of supports actually carrying pipe weight in a vertical orientation cannot exceed 25 ft per Section 17.4.5.5 in order to impose a limit on just how much such a hanger can support. Hope this helps, Ryan L. Hinson, PE*, SET** \ Burns & McDonnell Associate Fire Protection Engineer O 612-900-3755 \ M 763-688-4045 \ F 952-229-2923 [email protected]<mailto:[email protected]> \ burnsmcd.com<http://www.burnsmcd.com/> 8201 Norman Center Drive, Suite 500 \ Minneapolis-St. Paul, MN 55437 *Registered in: AK, LA, MD, MN, PA, TX, & UT **NICET IV - Water-Based Systems Layout [cid:[email protected]] From: Greg McGahan <[email protected]> Sent: Wednesday, January 4, 2023 9:21 AM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]> Subject: [Sprinklerforum] Re: Pipe Stands We have an open discussion going about a similar issue on a base so I have a question about the clamps being used to support the drops to the walls. Maybe we are misinterpreting Section 9.2.5.3 (16 ed) or the clamps you are referring to are not being mounted to the wall with rod, but if we used the traditional support with a riser clamp and two rods back to the wall, we could not count those as vertical supports, correct? Thank you, On Tue, Jan 3, 2023 at 6:32 PM Hinson, Ryan <[email protected]<mailto:[email protected]>> wrote: Ken, No worries, my friend. Together, we hopefully make everyone better. I need a little redirection now and then. I admittedly misread the initial email. I saw supporting the drops off the wall but not verification that these were also supporting some of the load. My initial response was based on that. Dennis, 1. I would first determine the load the pipe stand is really supporting based on assumed even distribution of the water-filled pipe weight(W) through the loop over the pipe support/hanger spacing you have (height of vertical pipe supports matters) assuming each support is carrying the weight of pipe to half-way between it and the next support (the pipe stand is supporting the loop piping to half way up to the wall supports). 2. Follow NFPA 13 direction to find the 5*W + 250-lb load required in the pipe stand. 3. Show verification that each component can support that load as per its cutsheet. Happy New Year! Ryan L. Hinson, PE*, SET** \ Burns & McDonnell Associate Fire Protection Engineer O 612-900-3755 \ M 763-688-4045 \ F 952-229-2923 [email protected]<mailto:[email protected]> \ burnsmcd.com<https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.burnsmcd.com%2F&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758578061%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=1HR%2BtO3CzTAzqLgefAAgomH%2Fz40y9HuOKl%2BjEIv%2FU0E%3D&reserved=0> 8201 Norman Center Drive, Suite 500 \ Minneapolis-St. Paul, MN 55437 *Registered in: AK, LA, MD, MN, PA, TX, & UT **NICET IV - Water-Based Systems Layout [cid:[email protected]] From: Ken Wagoner <[email protected]<mailto:[email protected]>> Sent: Thursday, December 29, 2022 4:39 PM To: [email protected]<mailto:[email protected]> Subject: [Sprinklerforum] Re: Pipe Stands As much as I dislike taking a different position from you on any issue Ryan, I see the provisions of §17.4.5.5 quite differently than the one you've taken. I believe that what Dennis has told us is that clamps are in place to support the drops "to the walls". Speculating that those clamps are roughly halfway down or up each side that would make the distance between supports less than 25', as it would include the pipe stand. And now that I review your thoughts carefully, Ryan I do note that if those clamps are not in place then the risers are not supported properly per §17.4.5.5 as you noted. How about some further clarification Dennis? Ken Wagoner, SET Parsley Consulting 500 West Mechanic Street Harrisonville, Missouri 64701-2235 Phone: (760) 745-6181 Visit the website<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flinkprotect.cudasvc.com%2Furl%3Fa%3Dhttp%253a%252f%252fwww.parsleyconsulting.com%252f%26c%3DE%2C1%2CY5zKJKPEh1mBEBqSR-VE9cUKl5y-eyP8BpvmE_5j9ZqW2eJbNphYzrCMBZ-2YuX6d-RRkHI4gQ1FV-cvOeCfRC58uZS9NiToZv2mx7909oCqLvCW_n5hDHeK%26typo%3D1&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758578061%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=xy5Ojp0SAIUzC6OA4gTkKFkNCwCT6shx5D8UJQuOu7c%3D&reserved=0> On 12/29/2022 3:20 PM, Hinson, Ryan wrote: Dennis, It appears that you have a 25-ft auxiliary system loop of 4" pipe from deck to grade and back which must be properly supported. I think your reviewing engineer's concern may justified with how this pipe is supported as you are at the maximum 25-ft vertical distance between hangers on vertical piping per NFPA 13 (2022) Section 17.4.5.5 and you actually have one 25-ft- and one 23-ft long vertical pipe stack. Do you have hangers within 2 ft of the top of each of the drops per Section 17.4.5.1? Even so, this single pipe stand at the base appears to be supporting twice the normally anticipated pipe stand load due to loading distribution where the bottom support must be sufficient for the bottom half of two vertical pipes - totaling approximately 25 ft of 4" water-filled pipe...which is nearly twice the typical loading of a single support due to spacing limitations of the same. Assuming Sch 40 pipe, I get the following load this pipe stand must support: (10.78 lbs/ft) * 25 ft * 5 + 250 lbs = 1597.5 lbs It is my opinion that per Section 17.5.1, you must EITHER: 1. Use off-the-shelf components in accordance with their listings/listed loadings per Sections 17.5.2 through 17.5.7 whose listings are further explained in Section A.17.1.6.1 for the load indicated above. OR 1. Obtain hanger configuration certification from a licensed PE which includes all the mandates in Section 17.5.1.2. Hope this helps, Ryan L. Hinson, PE*, SET** \ Burns & McDonnell Associate Fire Protection Engineer O 612-900-3755 \ M 763-688-4045 \ F 952-229-2923 [email protected]<mailto:[email protected]> \ burnsmcd.com<https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.burnsmcd.com%2F&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758578061%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=1HR%2BtO3CzTAzqLgefAAgomH%2Fz40y9HuOKl%2BjEIv%2FU0E%3D&reserved=0> 8201 Norman Center Drive, Suite 500 \ Minneapolis-St. Paul, MN 55437 *Registered in: AK, LA, MD, MN, PA, TX, & UT **NICET IV - Water-Based Systems Layout [cid:[email protected]] From: Dennis Wilson <[email protected]><mailto:[email protected]> Sent: Thursday, December 29, 2022 1:53 PM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]><mailto:[email protected]> Subject: [Sprinklerforum] Re: Pipe Stands Thanks ken, I've read the chapter. But this is the architect/engineer from hell. He has disapproved every submittal from every trade several times over, causing extreme delays, and everyone is banging their head against the wall. He wants proof, and I'm not sure how to go about figuring out an equation. Dennis Wilson Blackhawk Auto. Sprinklers Cedar Falls, Iowa 1-319-266-7721 From: Ken Wagoner <[email protected]<mailto:[email protected]>> Sent: Thursday, December 29, 2022 12:51 PM To: [email protected]<mailto:[email protected]> Subject: [Sprinklerforum] Re: Pipe Stands Dennis, You did not indicate which edition of -13 is applicable, however some good supporting information can be found in the 2019 edition in §17.5 regarding pipe stands. Make sure to read all of it, as it allows but does not require certification by a registered PE. As I am a principal member of the committee on hanging and bracing, please see the disclaimer below. have a safe and Happy New Year to everyone, Ken Wagoner, SET Parsley Consulting 500 West Mechanic Street Harrisonville, Missouri 64701-2235 Phone: (760) 745-6181 Visit the website <https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flinkprotect.cudasvc.com%2Furl%3Fa%3Dhttp%253a%252f%252fwww.parsleyconsulting.com%252f%26c%3DE%2C1%2CY5zKJKPEh1mBEBqSR-VE9cUKl5y-eyP8BpvmE_5j9ZqW2eJbNphYzrCMBZ-2YuX6d-RRkHI4gQ1FV-cvOeCfRC58uZS9NiToZv2mx7909oCqLvCW_n5hDHeK%26typo%3D1&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758578061%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=xy5Ojp0SAIUzC6OA4gTkKFkNCwCT6shx5D8UJQuOu7c%3D&reserved=0> IMPORTANT NOTICE: This correspondence is not a Formal Interpretation issued pursuant to NFPA Regulations. Any opinion expressed is the personal opinion of the author and does not necessarily represent the official position of the NFPA or its Technical Committees. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services It should be noted that the above is my opinion as a member of the NFPA Automatic Sprinkler System Hanging and Bracing Committee and the Hanging and Bracing for Fire Suppression Systems Committee in accordance with the NFPA Regulations Governing Committee Projects and should therefore not be considered, nor relied upon, as the official position of the NFPA or its Committees On 12/29/2022 11:47 AM, Dennis Wilson wrote: I have a 4" main @ 30' AFF, I drop down w/ 4" to a 12" arm-over then up to a b'fly va. & Aux. Dry Va., then proceed back up to 28' AFF to feed a dry system. On the 4x 1'-0" arm-over we installed a pipe stand. (the arm-over is 5-0 above the floor) We also use clamps to support the drops to the walls. The engineer is asking for proof that the pipe stand can support the load. This is install and hasn't fallen is not enough proof. Anyone have a way this can be done? Dennis Wilson Blackhawk Auto. Sprinklers Cedar Falls, Iowa 1-319-266-7721 _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.firesprinkler.org%2Flist%2Fsprinklerforum.lists.firesprinkler.org&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758734285%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CIN0j%2BHAZCP4tKnANE7GUSNK3YXze56%2B54DnoZwdM6c%3D&reserved=0> To unsubscribe send an email to [email protected]<mailto:[email protected]> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.firesprinkler.org%2Flist%2Fsprinklerforum.lists.firesprinkler.org&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758734285%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CIN0j%2BHAZCP4tKnANE7GUSNK3YXze56%2B54DnoZwdM6c%3D&reserved=0> To unsubscribe send an email to [email protected]<mailto:[email protected]> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.firesprinkler.org%2Flist%2Fsprinklerforum.lists.firesprinkler.org&data=05%7C01%7Crhinson%40burnsmcd.com%7C7fe17b60acff442a3e0508daee675073%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C638084424758734285%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CIN0j%2BHAZCP4tKnANE7GUSNK3YXze56%2B54DnoZwdM6c%3D&reserved=0> To unsubscribe send an email to [email protected]<mailto:[email protected]> -- Greg McGahan Genesis Fire Services, LLC 4912 Glover Lane. 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