# Glass Bulb Sprinklers - Lack of Fluid



## Insurance Engineer (Oct 10, 2010)

I saw this on another board and think it is was something we should be on the lookout for. I hope it is not a problem posting it here, if it is moderators then please delete.

From

Jon Nisja, Supervisor

MN State Fire Marshal Division

Our office has seen a significant number of glass bulb sprinklers only partially filled with fluid. They have come from different jobs, done by different contractors, at opposite ends of the state, and by different manufacturers. The majority of the sprinklers sold here are Tyco and Reliable models. We have been in contact with both manufacturers; they seem to indicate that they have not heard of this from anyone else but us. The engineers at Reliable have advised us that the sprinklers will not activate at the rated temperature; it would likely take temperatures hundreds of degrees higher to activate the sprinklers.

We have also seen a number of completely empty glass bulb sprinklers; these could often be traced to mechanical damage. There seems to be no logical explanation as to how some of the fluid left the glass bulb. From what we have found out, the glass bulb is made by two manufacturers; both of them in Europe. They are then sold to the various sprinkler manufacturers and installed in their sprinklers. Both the glass bulb manufacturers and the sprinkler manufacturers claim that all glass bulbs and sprinklers undergo a rigorous testing and inspection program. What is frustrating to us is that it appears that these defects are not noted in the glass bulb manufacturing process, the sprinkler manufacturing process, or the actual installation (by sprinkler contractors and fitters). We have collected 6-8 of these sprinklers from various installations (some new and some existing) across the state.

 Yesterday, we had a meeting with several sprinkler contractors and one of them advised us that they received a case of sprinklers recently; several of these glass bulbs were partially full. They sent them back to the manufacturer.

 We have also had a handful of instances of glass bulb sprinklers losing the coloring of the fluid (they are clear). Although this makes it difficult to determine the activation temperature, we are less concerned that they will not activate than the partially filled glass bulb sprinklers. Again, the manufacturers have no explanation and claim that they have not heard of it from other parts of the country.

 Since many of the E-PARADE members have extensive experience with sprinklers, we are looking for your comments, advice, or suggestions. I have attached a couple of photos.  Has anyone else seen this? Does anyone have any theories on what is happening?












From:

Dana Haagensen

Fire Protection Engineer

Division of Fire Safety

Massachusetts Department of Fire Services

Jon - This issue came up on the NFPA Committees a few years ago.  I don't believe who is to blame was ever resolved.  There was a lot of finger pointing between the manufacturers and the installing contractors.  However, the debate is what led to the listing labs, and the manufacturers, to come up with the protective shipping caps.  NFPA requires those covers to remain in place until after the sprinkler has been installed.  In some case, the cover must remain in place until the system is put into service.

Manufacturers claim these defective bulbs must be field/shipping induced, as every glass bulb is factory tested.

Contractors claim the phenomenon occurs even when sprinklers are properly installed and/or the defective sprinklers are shipped that way.

In my inspections, I have run into only one glass bulb with no fluid in it.  I can't recall running into a partially filled bulb.  I have talked to some inspectors that have run into a couple of colorless fluid filled bulbs.  To my knowledge, the colorless ones were related to sunlight exposure (uv fading), as they were located in skylights or near windows.

We should encourage that all defective sprinklers be submitted to the Consumer Product Safety Commission (CPSC) so that they can properly track the situation by make/model and look for nationwide trends.  If you haven't already done so, you should befriend your local CPSC investigators.


----------



## cda (Oct 10, 2010)

Interesting,  have not seen it, but will start looking closer

Sounds like some great quality control


----------



## FM William Burns (Oct 10, 2010)

Very relevant information InsEng.

I also trust the source since I served with Jon (the Chair) on the NFPA North Central Fire Code Committee for many years and if he provided information on the subject and what they are seeing in the field, it's golden.


----------



## RJJ (Oct 13, 2010)

Good post! Now I need to look closer.


----------



## Glennman CBO (Oct 13, 2010)

Our fire inspector (who now works for the state) has made note of this.

My question is this: why did they ever go to these? It seems like the old lead soldered style would be less trouble.


----------



## cda (Oct 13, 2010)

Quicker response???

Less moving parts???


----------



## Glennman CBO (Oct 13, 2010)

cda, that's probably it.


----------



## Coug Dad (Oct 13, 2010)

Their marketing push was to the architects since they look sleeker and better than the old link and lever or the center strut sprinklers.  I even once had an architect who wanted to specify the color of the fluid based upon the look and not the temperature rating.


----------



## RJJ (Oct 13, 2010)

Cheaper also! No one wants lead anymore either.


----------



## Dr. J (Oct 13, 2010)

One plus is that they are inspectable.  How would you tell if a solder link was compromised?


----------



## Insurance Engineer (Oct 14, 2010)

cda said:
			
		

> Quicker response???Less moving parts???


Quicker ??, if you look at the sprinkler temperature rating of a glass bulb you will note they are usually about 10F less then a metal type fusable link. 155F for a glass bulb vs 165F for metal a link and lever sprinkler. Because it takes a while to heat up the fluid in the glass bulb the mfg will decrease the temperature to compensate so they both have the same RTI. See below from NFPA 13 on RTI.

Less moving parts yep

Sprinklers defined as standard response have a thermal element with an RTI of 80 (meters-seconds)1/2 or more. The response time index (RTI) is a measure of the sensitivity of the sprinkler’s thermal element as installed in a specific sprinkler. It is usually determined by plunging a sprinkler into a heated laminar airflow within a test oven.


----------



## peach (Oct 16, 2010)

the ones with yellow fluid are much harder to see.. (I don't remember the temp rating for those)...


----------



## FM William Burns (Oct 16, 2010)

Intermediate 175 to 225 F..........  I like the green liquid myself


----------



## RJJ (Oct 17, 2010)

Green or red is fine! I haven't see the yellow! Who makes them!


----------

