Dry Sprinkler System Affected by Freezing Temp?

2/1/2024

Would a dry fire suppression system be affected by freezing temperatures?

I work at a facility that had a glass sprinkler break, no contact or anything, and of course the water came out as it should.

We've had freezing temps for the last few days, but where it broke was in an 74 degree room, so not frozen.

Any ideas on why this would have happened?

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9 Comments

Dan Wilder

2/1/2024 06:47:21 am

The room is 74 degrees but is fed from a dry sprinkler system?
Are there heaters in the room? How old is the sprinkler? What type of sprinkler (QR/SR)?

Any number of possibilities including:

Incorrect storage and handling prior to install
Incorrect installation (torque) or not with correct sprinkler wrench
-If they used channel locks or a crescent wrench, you will see the markings (rounding, indents) on the right side of the wrench boss as this would have been the contact point for the tool to tighten
-Check sprinkler threads for cross threading to start
Nearby heat sources
Impact
Incorrect temp installed (look at top of deflector for temp info)

...and yes, MFG defect but this is difficult to prove and rare but it does occur.

Dan Wilder

2/1/2024 08:20:43 am

I'll add - was the room unheated until recently?

If it was cold and there was an ice plug at that location (damaging the sprinkler and/or fitting), the warming of the room could have thawed the plug and activated the system.

We don't often get service calls on cold days, we get them a day or two afterwards when things warm up.

Anthony

2/1/2024 07:54:38 am

With out knowing more it could be a case where the bulb broke a while back and never fully let go. A slight nock that cracked the bulb but no one noticed the bubble wasn't there. A surge in pressure in the system or a rattle in the building that made its way to the pipes ended up shaking the bulb loose letting the sprinkler go off.

Sprinklers don't activate with freezing temperatures you're more likely to have a fitting break. So I wouldn't suspect that to be the cause.

Franck

2/1/2024 09:18:58 am

As indicated above, the most obvious possible reason is related to the installation of the sprinkler with some damages (undetected until the issue happens).
Another possible reason outlined by Dan could be related to the fact that the room is freezed and warmed and freezed and warmed... again and again...
In that case, humidity is susceptible to collect at the sprinkler and freeze, thus damaging the thermal element area. When temperature goes down and water melts, then the problem occurs!

Jesse

2/1/2024 11:17:35 am

I'm curious about the dry-system protecting a 74-degre room. Regardless, the sprinkler could have been damaged (likely) or defective (less likely).

Todd E Wyatt

2/1/2024 11:41:16 am

Some of the responses allude to possible past damage to the sprinkler's glass bulb heat-responsive element.

NFPA 25-2023 (Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems) requires sprinklers to be "inspected from the floor annually."

NFPA 25 cautions in the ENHANCED CONTENT (see below) ... Inspectors who use a flashlight or binoculars must be careful about false positive results, which can occur when the light reflects off the white printing on glass bulb sprinklers.

I recommend conveying this info to your current (and future) sprinkler system inspectors.

NFPA 25-2023
Chapter 5 Sprinkler Systems
5.2* Inspection.
5.2.1.1*
Sprinklers shall be inspected from the floor level annually.

ENHANCED CONTENT
FAQ
How do I inspect sprinklers that are located in a warehouse with high ceilings where it is difficult to determine their condition?

Paragraph 5.2.1.1 requires a visual inspection of sprinklers to reveal obvious signs of damage, leakage, loading, or corrosion. Inspections are conducted from the floor level; this is because it is usually impractical to get closer to the sprinklers for a more in-depth inspection, and the use of ladders is of limited benefit when compared to the cost. In buildings with high ceilings, a flashlight or binoculars can assist in the inspection of sprinklers, piping, hangers, and other components. When other work is being done at the ceiling level using ladders or lifts, personnel could take advantage of the opportunity of being closer to the sprinklers to inspect the system.

Inspectors who use a flashlight or binoculars must be careful about false positive results, which can occur when the light reflects off the white printing on glass bulb sprinklers. This is also a point of contention with some building owners who mistakenly see the use of additional resources not mandated by the standard, such as a flashlight or binoculars, as an effort to generate service work, as opposed to an effort to ensure a properly working sprinkler system. As with most issues, a little communication goes a long way in helping the owner understand why it is so important to look closely at the sprinklers.

5.2.1.1.1*
Any sprinkler that shows signs of any of the following shall be replaced:
4) Loss of fluid in the glass bulb heat-responsive element

Dan S.

2/1/2024 05:14:43 pm

I bet you had water accumulation above sprinkler head in un heated area/attic that froze then thawed pushing out element. A lot of times the weakest link breaks first.

Hopefully it is a dry pendent but either way the system wasn’t properly drained/maintained or the piping does not have the proper pitch.

I literally just finished a freeze up today that was similar to this. This particular one tripped due to loss of heat in riser room. Froze before dry valve when maintenance realized it and added temporary heat it thawed pushing dry valve clapper open. Maintenance drained pretty quick but it almost instantly froze in areas of the system. Left system down until it thawed. 8 dry heads busted(in heated rooms) and some fittings blew apart in attic. No water damage since system was off just some water stains on ceiling.

Chris

2/8/2024 09:11:07 am

What I have personally seen happen is the pipe will have water in it that freezes and as that water expands it will push out the sprinkler sealing assembly out of the sprinkler head but since the pipe is frozen solid it will stay sealed up until it eventually starts to thaw out. Then once it starts leaking air and the compressor starts running, it'll thaw out quickly as the air from the compressor gets hot and then the system trips. Years ago I went to fix a leak at a retirement facility because a head was leaking from it breaking from the freezing temp, when I got in the attic found that the head supplied the leaking dry SSP and then SSU's in the attic, the dry SSP was what had been leaking but every single SSU down the line was also broken but the orifices were still sealed up from the ice plugs so they hadn't leaked, and even cooler was a gasket on a mechanical tee was pushed out of its groove from an ice plug.

tyrone loukas link

6/27/2024 09:28:12 am

Thank you for addressing the concerns regarding dry sprinkler systems affected by freezing temperatures. Your insights and advice are invaluable in helping us understand the potential challenges and ensuring the proper functioning of these systems in colder conditions. Your expertise is greatly appreciated in promoting safety and reliability in fire protection systems.

Dry Sprinkler System Affected by Freezing Temp?

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