MeyerFire
  • Blog
  • Forum
  • TOOLKIT
    • ALL TOOLS
    • BUY THE TOOLKIT
  • UNIVERSITY
    • ALL COURSES
    • JOIN THE UNIVERSITY
  • PE Exam
    • PE Forum & Errata
    • PE Store
    • PE Tools
    • PE PREP SERIES
    • PE 100-Day Marathon
  • LOGIN
    • TOOLKIT-ONLY LOGIN
    • UNIVERSITY LOGIN
  • PRICING
    • SOFTWARE & TRAINING
    • STORE
  • OUR CAUSE
    • ABOUT MEYERFIRE
    • JOB OPENINGS
    • BECOME AN INSTRUCTOR
    • HELP/SUPPORT
Picture

Correct Way to Support Long Sprinkler Drop?

6/1/2020

11 Comments

 
I have a question id like a second opinion about. I have a client with a new build boat storage facility, approx 30 ft high, at one end on the ground floor is an office area with a suspended ceiling. The installers have used U-Bolt Mechanical Tee couplings to attach the drops to the branch line, and then hung 20-ft of 1" pipe as the drop.

What is the correct way to secure these drops?

There is currently no lateral or vertical support. This is not in a seismic area.

​​​Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe
11 Comments
Dan Wilder
6/1/2020 08:23:42 am

As you reference there is no seismic qualifications...there is nothing in NFPA to require additional hanging if the arm overs comply with the requirements of "Unsupported Lengths" in whatever year is your applicable standard.

This would fall under installer common sense, not NFPA. If the MT are drilled out the same side of the branch line (horizontally), the line will have a tendency to spin due to the offset torque weight of the drops. In this case, best practice would be to provide a tee on the run and cap or at least a hanger between the BL and the ell before the drop on each piece of BL piping (if the BL is grooved) or every other MT for a threaded BL.

If they are drilled vertically from the bottom (poor drills...) and any arm-over occurs at the base of the drop (complying with NFPA for those unsupported lengths) then typically you are OK. If the AO is at the top for some reason, the previous hanging practice would be helpful.

As for any horizontal restraint for the drops, again, there is no NFPA requirement. The drop will have some natural sway available to it but no requirements to brace/restrain it.

Reply
mike
6/3/2020 01:24:48 pm

Thanks for taking the time to respond, much appreciated

Reply
Casey Milhorn
6/1/2020 10:56:44 am

Dan nailed it. Exactly what I was going to say. Have to watch the weight of the drop "spinning" the line, especially if its grooved above. Also, just the amount of stress being put on that armover is concerning. Definitely a hanger at the armover if it happens up top, nothing if it happens close to the office ceiling.

Reply
mike
6/3/2020 01:25:09 pm

Thanks

Reply
Shane
6/1/2020 11:39:52 am

I would suggest installing a mechanical tee close to the wall, drop down then arm over to the sprinkler head location for the office. Then you have the option to strap to the wall for support and hang the armover from the deck or steel above. I would especially use this method if there were many drops being supplied from above.

Reply
mike
6/3/2020 01:25:49 pm

Thanks for the feedback - good options

Reply
Mike
6/1/2020 01:15:22 pm

No requirements for restraint but that's a lot of pipe for a mechanical tee. Might end up needing a Tee, nipple and cap to the closest joist for hanging.

Reply
mike
6/3/2020 01:26:23 pm

Just doesnt look right ! Gives me cause for concern

Reply
Dale
6/5/2020 09:34:41 am

In the past, where we had large areas, we would install a new main at the lower ceiling level, tapping off of the main above, and use branch lines or arm-overs from that new main. While your work is already installed, this method may work for you in a future project.

Reply
George Naill
6/22/2023 10:11:50 am

So what if the drop is 35' and we are in a seismic zone D. We have a builder who is erecting tilt buildings with 40' minimum clear height to the bottom of the Girders, sprinklers are another 5 feet higher. Office areas have 10 to 11' ceiling to top of framing. The UPC for plumbing stipulates that metal threaded piping used for water supply be supported at every other floor but not to exceed 25' of vertical pipe. how does that or would it apply to Fire Sprinkler Supply. A few of these warehouses have been completed prior to my arrival with no support, they just hang down 35' form a short 12" or so long arm over. I'm Not a Fire Inspector yet but will be picking this up at some point once get the certifications.

I definitely think using the installer common sense approach doesn't work here. This is a seismic zone and if a 30' length of W36x 97 column un restrained during the 6.9 Nisqually quake was able to oscillate nearly 4' in diameter then an unrestrained 30+ foot sprinkler line is going to oscillate significantly more and if the only attachment is to the brace is a ceiling grid there is a high likelihood of the sprinkler pipe failing and punching through the ceiling.

Thoughts

Reply
Mike link
12/22/2023 12:20:21 am

What about a 1" x 9' wet system riser, do to removed drop ceiling replacing a pendent with an upright on a vertical pipe straight up 12" below metal roof deck. Does this have to be braced somehow to the open web I-beams or ? Please Advise............

Reply



Leave a Reply.

    SUBMIT A QUESTION
    Picture
    Why Sponsor?

    ALL-ACCESS

    Picture
    GET ALL OUR TOOLS

    SUBSCRIBE

    Subscribe and learn something new each day:
    I'm Interested In:

    COMMUNITY

    Top May '25 Contributors
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    SEE LEADERBOARD

    YOUR POST

    SUBMIT A QUESTION

    PE EXAM

    Get 100 Days of Free Sample Questions right to you!
    SIGN ME UP!

    FILTERS

    All
    A1171
    ABA
    ADA
    ASCE 7
    ASME A17.1
    ASTM E1354
    Blog Thread
    Daily Discussion
    Design-documents
    EN 12845
    Explosion Protection
    Explosion-protection-prevention
    Fire Detection And Alarm Systems
    Fire Dynamics
    Flammable And Combustible Liquids
    Flammable-combustible-liquids
    FM Global
    Human-behavior
    IBC
    ICC 500
    IEBC
    IFC
    IMC
    IPC
    IRC
    ISO
    Means Of Egress
    NBC
    NFPA 1
    NFPA 10
    NFPA 101
    NFPA 11
    NFPA 110
    NFPA 1142
    NFPA 1221
    NFPA 13
    NFPA 13D
    NFPA 13R
    NFPA 14
    NFPA 15
    NFPA 16
    NFPA 17A
    NFPA 20
    NFPA 2001
    NFPA 214
    NFPA 22
    NFPA 220
    NFPA 24
    NFPA 241
    NFPA 25
    NFPA 291
    NFPA 30
    NFPA 307
    NFPA 30B
    NFPA 31
    NFPA 33
    NFPA 37
    NFPA 400
    NFPA 409
    NFPA 415
    NFPA 45
    NFPA 495
    NFPA 497
    NFPA 5000
    NFPA 502
    NFPA 54
    NFPA 55
    NFPA 654
    NFPA 68
    NFPA 70
    NFPA 701
    NFPA 72
    NFPA 75
    NFPA 770
    NFPA 82
    NFPA 855
    NFPA 90A
    NFPA 92
    NFPA 96
    NICET
    OBC
    OSHA
    Passive Building Systems
    PE Prep Guide
    PE Prep Series
    PE Sample Problems
    Poll
    Smoke Management
    Special Hazard Systems
    UFC 3-600-01
    UFC 4-021-01
    UFC 4-211-01
    UPC
    Updates
    Water Based Fire Suppression
    Weekly Exams


    ARCHIVES

    June 2025
    May 2025
    April 2025
    March 2025
    February 2025
    January 2025
    December 2024
    November 2024
    October 2024
    September 2024
    August 2024
    July 2024
    June 2024
    May 2024
    April 2024
    March 2024
    February 2024
    January 2024
    December 2023
    November 2023
    October 2023
    September 2023
    August 2023
    July 2023
    June 2023
    May 2023
    April 2023
    March 2023
    February 2023
    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    November 2016
    October 2016
    July 2016
    June 2016


    PE PREP SERIES

    SEE LEADERBOARD

    RSS Feed

Picture
​Home
Our Cause
The Blog
The Forum
PE Exam Prep
The Toolkit

MeyerFire University
​Pricing
Login
​Support
Contact Us
Picture

MeyerFire.com is a startup community built to help fire protection professionals shine.
Our goal is to improve fire protection practices worldwide. We promote the industry by creating helpful tools and resources, and by bringing together industry professionals to share their expertise.

​MeyerFire, LLC is a NICET Recognized Training Provider and International Code Council Preferred Education Provider.

All text, images, and media ​Copyright © 2016-2025 MeyerFire, LLC

We respect your privacy and personal data. See our Privacy Policy and Terms of Service. 
The views, opinions, and information found on this site represent solely the author and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence.

Discussions are solely for the purpose of peer review and the exchange of ideas. All comments are reviewed. Comments which do not contribute, are not relevant, are spam, or are disrespectful in nature may be removed. Information presented and opinions expressed should not be relied upon as a replacement for consulting services. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a small commission for orders placed elsewhere.

  • Blog
  • Forum
  • TOOLKIT
    • ALL TOOLS
    • BUY THE TOOLKIT
  • UNIVERSITY
    • ALL COURSES
    • JOIN THE UNIVERSITY
  • PE Exam
    • PE Forum & Errata
    • PE Store
    • PE Tools
    • PE PREP SERIES
    • PE 100-Day Marathon
  • LOGIN
    • TOOLKIT-ONLY LOGIN
    • UNIVERSITY LOGIN
  • PRICING
    • SOFTWARE & TRAINING
    • STORE
  • OUR CAUSE
    • ABOUT MEYERFIRE
    • JOB OPENINGS
    • BECOME AN INSTRUCTOR
    • HELP/SUPPORT