Clear glass bulb type sprinkler heads?

[Tom Sutton]

The plant in question is a clean assembly plant for plastic ball pens.

The other day I came across a new situation for me - nearly all the glass bulb type sprinkler heads in a plant, had discoloured liquid in the bulbs - it was completely clear. The plant is only 8 years old and there seemed to be no special reason, like strong sunlight or UV light or anything unusual. I noticed this situation in the offices. The factory roof sprinklers were too high to see if this had occurred with them as well.

What has happened and do you think these sprinkler heads are still OK?

I'd be pleased to receive your thoughts on this unusual state of affairs.

Any observations to my latest query?

[kurnal]

Tell him to look in the pump house- there should be a number of spare heads. These will have been kept in the dark and so should be as new. There may be some spares of different temperature rating but he should get an indication. As a backup the operating temperature is usually stamped on the deflector. But I too have never seen any completely clear ones.

[AnthonyB]

I asked this question on an international sprinkler group for you, here are the replies to date (excuse the NFPA references there are a lot of US people in the group)

Chris Logan Could be a bad batch of heads? Ask the manufacturer if any known issues where brought to there attention

Gary Shelly Makes you wonder if they use some sort of lighting that emits higher levels of UV light.

Robin Ken Lillskrubb had the same over here, replaced everyone and tested the clear ones with 16bar pressure, none of them held the pressure.

Michael Steedman We have never had that problem in Australia do you know the brand of heads used, will keep this issue in mind thanks for the update

Ryan Ahl Check with Greg Cloutier, he just posted something recently about this, he came across a Viking upright I believe that had clear liquid. Could be a Viking issue if they are the manufacturer of heads you saw.

Greg Schmitz Are you certain they are clear and not yellow? 175 yellow heads look clear under some circumstances, especially if you're used to looking at mostly red and green.

NFPA 25 does not address this, only requiring replacement if the fluid has emptied. I would urge replacement, however, as clear fluid makes it impossible to inspect heads from ground level and verify temperature rating and that fluid is present.

BJ Lock Ummmmm.....if the fluid is clear....then this is a critical deficiency ....
They should be changed immediately.
There really is no other proper answer....

Greg Schmitz Personally, I would write it up, but if the bulb is still full, color is more or less just a convenient way to check the temperature rating. The rating is stamped on the deflector as well.

http://www.fmglobal.com/FMGlobalRegi.../Vshared/FMDS0281.pdf

Found this, by Factory Mutual. Still need a reference to an NFPA standard. Section 2.3.8.5 I believe, says change if clear. Good practice if FM says to, but still need a code reference....See More

Robin Ken Lillskrubb Totally clear only. Tested quite a bit with the Ultrafog Sprinklersystem, since there comes almost no water at all, can walk through the fog without getting really wet.
Had clear heads in a Sauna and we just let them be and turned the Sauna on, turned out they blew out @ 120°c and should've held 185°c

[Tom Sutton]

I have just received an update,

Hi Tom and all those who helped with their points of view.
 
Unfortunately I didn't think to check the make, but was assured that they were red bulb originally - almost certainly manufactured in the USA due to the plant being located in Tijuana, Mexico.
There was no water leakage of any of the heads at the firemain pressure of 110 psi.
 
I contacted an old boss of mine in the UK who, together with me, designed sprinkler heads some 47 years ago, and he said that they used to have some batches of bulbs that had this problem, so they started to put samples on the roof to be exposed to strong sunlight (such as it is in the UK).
Some discoloured but he assured me that the heads still operated perfectly well; it was simply that the dye was not as permanent as it should have of been.
 
One disadvantage is that from ground level, it is impossible to ascertain if roof mounted heads in the production area have simply discoloured, or have cracked and leaked out their inside fluid - a highly unlikely possibility but this would be critical if it occurred.
 
Quite honestly, I told the client and the company (I'm an insurance surveyor) that the current situation was not critical.
 
Many thanks to all for your valuable input.
Best regards from sunny Mexico.