Whatd'ya Call Each Pipe in a Sprinkler System?

11/29/2023

You’re on a jobsite. On the phone with the boss back at the office. You’re looking up at a portion of the sprinkler system and have a question about that one piece of pipe.

How do you describe that piece of pipe?

What’s it called?

It sounds silly, but up until Monday I’m not so sure that I knew the proper name for each segment within a sprinkler system. Like the true, proper terms that I should have learned way back when.

There are a few things that can impact that – one is informal regional terms, which can cause some inconsistency. One is that up until Monday I’d never actually read all the definitions in NFPA 13 for each stick of pipe. One is that when I’d get cross-eyed looks when talking about a specific piece, I’d usually just point to it in conversation and move on.

Well – as we do around here – it’s time to bring this topic out into the light and maybe we can all learn a bit from the discussion.

Here’s a basic diagram of a sprinkler system, which each pipe path identified as best I understand it today:

Is this consistent with the terms you use? What other names (maybe keep it PC?) or terms do you use?

If not, what terms (even informal ones) do you use to describe each pipe?

Take a look at the diagram above and some of these pictures and let us know here.

Craig S.

11/29/2023 10:17:28 am

I agree with what you have labeled. The only thing I’d add is that I’ve heard an armover on a riser nipple being called either a return bend or a mud loop.

Josh

11/29/2023 10:21:23 am

Good point. Most of the subs I talk to call them return bends.

Angie Kamm

11/29/2023 10:22:53 am

I have heard gooseneck as well as return bend.

11/29/2023 10:27:53 am

My understanding is that an armover comes off the side of a branch line and then drops down to a sprinkler (one tee, one elbow), while a return bend goes up and then over and then drops down to the sprinkler (one tee, two elbows).

Chad

11/29/2023 10:24:47 am

Once again a great teaching tool, thank you Joe!

Very consistent. Outrigger is a new one to me though.

When its not gridded I call branch lines the tree some times (branch is part of a "tree")

Mark Wiedeburg

11/29/2023 10:52:40 am

Outrigger is also new to me. We have always called these "tail backs"

Adam

11/29/2023 10:27:17 am

For the gridded system, I refer to the Cross Mains as Near and Far Mains in their relation to the riser.

Carl

11/29/2023 10:38:05 am

"Floating main" for the back main.

Steven

11/29/2023 11:10:30 am

Primary Main, Secondary Main, Tertiary Main is what I normally go with for gridded systems. Never ended up with a fourth main but this naming system keeps going and I am sure we all have used Primary and Secondary.

Ryan Barduhn link

12/18/2023 03:30:10 pm

We usually call the 2 cross mains the LIVE main and the DEAD main.

Jesse

11/29/2023 10:28:24 am

I learned from a guy on 13 and he mentored me for years. The only thing I see different from what was drilled into my noggin is in lieu of "front main" and "back main"; Near Main and Far Main on a gridded system relative to the riser

Tommy Hintz

11/29/2023 10:33:12 am

We call the outriggers "tailbacks"

Joe Meyer

11/29/2023 10:35:35 am

I haven't heard that one, but I like it. Is that a football reference?

Dan Wilder

11/29/2023 10:40:43 am

Dead main (the secondary Cross Main)

Swing - The last arm-over to a drop into a sprinkler

Rooster Tail - Horizontal 1" nipple to a 1 x ½ or ¾ x 1 tee (for an upright) and a 1" plug or drop for a TI or future TI

Gooseneck = Return Bend

Outrigger = Tailback

Dave

11/29/2023 11:30:50 am

Oh yeah I forgot rooster tail.

Jerry Clark

11/29/2023 10:49:36 am

The little thing that you screw the sprinkler head or sprig into is either a threadolet, or weldolet...trust me, I learned the hard way on this one.

11/29/2023 11:19:10 am

GREAT, FUN topic, and not just semantics, for example if it does not meet the definition of a branch line not a long armover (computer: add armover to dictionary) then I say it does not require branch line restraint.
Sometimes it depends on my audience; am I talking to a non-sprinkler person, or a fitter? Drum drip vs. condensate nipple, water motor gong vs. Mechanical sprinkler alarm, flexible drop / flex drop / whip, adjustable drop nipple vs. ADN… sodium silicate solution or water glass, haha… (If it’s a fitter, that also opens it up to descriptive terms like NFG, T-U….)
I believe there are regional things too, long ago someone told me that “back east” they called shaped-nipples “grooved stubbies?” (Was that a myth?) How are these terms used and spread? Joe, maybe sprinkler terms superimposed over a map of the US.
As far as the pipe in the illustration, those are pretty much the terms I use, primary or near main / far or secondary main (Oh yeah Carl, “floating main”), riser nipple, outrigger, branch lines… Depending on what I had for breakfast sprig or stub-up; return-bend or gooseneck; pipe-o-let or weld-olet. I don’t think I’ve used “service entry,” Depending on context, supply flange (even if it is an IBR) or underground supply. This thread will be fun to check again later in the day.
And I’m in the minority in that the only time I use the term “head” rather than “sprinkler” is if I’m talking about a head-guard or end-head. That IS a hill I will die on!

Eric R

11/29/2023 11:23:28 am

Nice graphic!

I think it's good to note that the term outrigger(tailback) is not a NFPA defined term.

While the term is very useful to an installer to help them quickly identify that the piping is not part of the grid, from a designer perspective that piece of pipe would be either a "branch line" or "arm-over" depending on the number of heads it supplies. This can matter when laying out hangers and more importantly seismic restraints.

Also that the arm-over designation can apply to a horizontal pipe connecting a drop, a sprig, a sprinkler at the same elevation, or even two sprinklers if they are above and below a ceiling.

Michael Millman

11/29/2023 12:34:21 pm

I agree with most of what you have here. Here are some things I'd add/modify:

Feed main I also sometimes call "bulk main" (or if it's part of a combination standpipe/sprinkler system connecting multiple standpipe risers, I may call it the "standpipe interconnect").

Primary main/front main, sometimes I will call the "live" main.
Secondary main/back main, sometimes I will call the "dead" main.

For the armover, I agree, however if it goes UP and over, we'll usually call them a "gooseneck" (or more formally, a return bend).

Sometimes, it's beneficial to have a third main in a complex grid (or even a second feed main in cases where a single large diameter pipe won't fit, but two smaller diameter ones may fit adjacent to each other), in which case I may call that extra main an "express main" or something like that.

Since you said to keep it PC, I'll leave out some of the more colorful names I've heard for things like exposed pendents with two piece escutcheons (for those that know, the initials are "DD").

DAVE

11/29/2023 06:53:44 pm

Like the one-piece HCE's?

Anthony Brown

11/29/2023 01:20:17 pm

For many years I called sprigs "candlesticks. Use "sprigs" (up/dn) on the plans, candlesticks in conversation and as an Engineer I say "condensate drain".
For my own purpose I define "armover" as one head moved no more than 24"

Tony

11/29/2023 04:50:03 pm

We call any cross main that isn't attached to a feed main a floating main.

11/29/2023 07:11:57 pm

Of couse the definitions chapter of 13 has:

ARM-OVER - A horizontal pipe that extends from the branch line to a single sprinkler or a sprinkler above and below a ceiling
BRANCH LINES -The pipes supplying sprinklers (NOT HEADS), either directly or through sprigs, drops, return bends, or arm-overs.
CROSS MAINS - The pipes serving the branch lines, either directly or through riser nipples.
FEED MAINS - The pipes supplying cross mains, either directly or through risers.
RISER NIPPLE - A vertical pipe between the cross main and branch line
SPRIG - A pipe that rises vertically and supplies a single sprinkler

I appreciate this thread, I'm going to mess with my colleagues by randomly using the terms tailbacks and candlesticks.

Patrick

12/1/2023 12:11:01 pm

I would consider the feed main on your diagram a cross main because it has an outlet for a branch line. Throw a coupling in before that outlet and then it becomes a feed main.

Fred Walker

12/5/2023 09:20:28 am

Building this drawing with all the variations becomes a useful definition tool.

For those working in multiple countries, it would be perhaps useful to see what the features are called in UK, EU, Japan, Korea and China.

Franck Orset

12/6/2023 07:42:28 am

Definetely different names as English is not the recognized language in Europe, Japan, Korea and China :)

For example, in France, the term for sprig will be translated into the equivalent to "candlestick". But we call it "chandelles".
Branch lines would be transleted into "antenna" (antennes in French).

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Whatd'ya Call Each Pipe in a Sprinkler System?

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