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Does this Meet Code 12

Flexible Armover Attachments

Sprinkler systems have seen an increase in the use of specifically listed equipment.  Flexible arm-overs serve a great purpose in sprinkler system installation but are heavily depended on proper installation per the manufacture listing requirements.

If you look at the first picture above you may say “Well it truly depends!”  So lets make a couple of assumptions:

  1. The system was properly designed to account for the friction loss of the devices
  2. The flexible armover is listed for use on sprinkler systems

So the question is, does this meet code…. oh and take a look at these pictures below

Flexible Sprinkler Systems

View of the flexible piping

Flexible sprinkler piping

So Mrs (or Mr.) Inspector, does this meet code?  How do you cite this if it is a violation?  Does it matter if your referenced version of NFPA 13 does not specifically address flexible arm-overs?

{ 13 comments… add one }

  • Builder Bob January 12, 2010, 9:31 am

    No – improper installation –
    Minimum Bend Radius:
    • 7″/178 mm (FM Approval for braided system)
    • 4″/102 mm for (UL Listing for unbraided system)
    • Do not bend within 2 1/2″ from connection nut.

    • Marshal Chris June 7, 2010, 9:00 pm


      Where is the requirement of the 2.5″ from connection nut?

  • Builder Bob January 12, 2010, 9:35 am

    ALSO< equipment or appliances are required to be installed in accordance with the listing of the device per manufacture's installation guide……

    This installation does not appear to meet those guidelines.

  • Roger Herin January 12, 2010, 9:37 am

    It does not appear to meet the manufacturer’s installation instructions of any flexhead sprinklers I’ve seen, because of the tight turn radius. In order to determine if it meets code or not, I would neet to see the manufacturer’s instructions and cut sheet, and the system design criteria. If it does not conform to those things, I would cite is as either not installed in accordance with its listing, or not in accordance with the approved construction documents – depending on which is violated. If the currently adopted issue of NFPA13 does not specifically address flex-head technology, then I believed the “new methods and materials” section would apply.

  • Dale Fahrney January 12, 2010, 9:54 am

    I’ve inspected several of these systems and in my humble opinion where they go wrong is exactly in this type of installation. When the Tee comes off in a horizontal direction that should tell you something. Each manufacturer has a spec sheet about the number of bends in the pipe allowed for it to still meet your code . We had a manufacturers Rep in to show all our inspectors in the area what to look for in “their product” and they at the time were the only american made product and they taught us to use a small coffee can on a stick/pole. If you cannot fit the can in the bend it is too sharp and the had a specific number of bends I believe it was 6 on a 36″ model. According to our manufacturer a bend is counted in the beginning, middle, and end of the bend that that would make (3) bends. This photo makes a clear indication that the bend it not correct and would restrict flow thereby messing with your hydraulics. Secondly if you’re not using the right code it very might well come down to a CBO making the decision to allow the flexible sprinkler parts or not.


  • Lou H January 12, 2010, 10:40 am

    I will begin having contractors have the manufacturers cut sheet available at the time of a rough inspection to be sure the installation does not exceed the maximum radius bends. Additionally, on a retro-fit commercial installation, light weight ceiling grids cannot be used. Be sure to review the new calculations, since the length of the flex drop can be much different than regular pipe.

  • Lloyd Montgomery January 12, 2010, 12:03 pm

    We have seen an increase in the use of flexdrops in our area and I will put my inspectors on notice to watch for this type of installation.Thanks Ed for the heads up.

  • Michael O'Brian January 12, 2010, 8:07 pm

    Bob, Roger, Dale, Lou, Lloyd,
    You guys know for a minute I thought I might have stumped you all. You all rock, and I received a bunch of emails from the readers today. This is a hot topic and we need to get a post out.

    From the building inspector point of view that drop ceiling needs to be installed per ASTM and the referenced is found in the listing materials of the device as well as in the building code.

    If you are approving systems with this install, approved drawings with calculations supporting the design are critical. This includes showing the correct length of the flex-drop. If your not sure ask for the detailed cut sheet. I can’t not say how helpful the staff at Flexhead or the other manufacture are. We will get a post out shortly!!!!

  • Paul Dove January 13, 2010, 9:17 pm

    I keep the following resources in my favorites for these specific types of issues in addition to always requiring the data sheets for all system materials and equipment:




  • Larry DeWachter March 2, 2010, 11:58 pm

    Thanks for the info Mike! We are seeing this used in State regulated facilitied throughout the State. I just talked to an inspector in the Gaylord office about this today.


  • Michael O'Brian June 1, 2010, 5:56 am

    Okay, it has been brought to my attention that the piping utilized in these pictures is a flexible armover, although it is NOT a “Flex Head” brand. Originally we had two references to Flex Head and we apologize for referencing that product which the pictures were not.

    I see that Mr. Dove has included links to Flex Head for their product, which demonstrates how important it is to have the correct listed information.

  • Michael Hangge August 13, 2010, 3:05 pm

    The first picture does not meet the requirements set forth by any manufacture that I am familair with. As “Builder Bob” has stated the FM and UL Listing. Also each manufacture my have a special listing for their type of pipe. Also the installer should have the manufacture installation information at the job site. If any one would like other pictures concerning different ways that this pipe has been installed incorrectly please contact me.

  • Poundcake February 21, 2012, 1:29 pm

    I found this site to have some great links to standards http://flexdropsprinkler.com/

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