Leaking 1983 Viking Model M .. several

[ContractorDave]

I've had a string of leaking sprinklers in a mall over the past year. They all seem to be occurring in the same area, a barber shop. There seems nothing significant about this area. It's a steel wet pipe system. Pressures in this area are typically 95psi. The sprinkler heads themselves are 1983 Viking model M SSP. Upon close examination there is a coating around the seal washer that has come away. I've attached two pics (hopefully). One is from a leak the other day where I have taken the sprinkler apart. Damage on the bell plug is from my doing so. The other pic is from a leak this morning. Has anyone encountered problems with these heads before?

Regards
Dave

 

[Sprink09]

I have seen similar problems occur in freezing conditions even when it appears to be warm at the height of the drop/drywall ceiling. Is the space above the ceiling getting cold during winter months? It could be the water is freezing just enough that it is expanding the brass head seat and yet not enough to damage the stronger steel hex coupling or drop piping. Just my view as we did not examine the seats etc. that closely because we found some ice still in the drop and the area above to have cold air blowing in from gaps in the structure.

 

[cdafd]

are there same heads in adjoining spaces, or did a company do this one space with different heads???


Send one to someone for analysis and testing???

 

[FFP1]

Defective heads or excessive pressure most likely. Have a representative sample tested and/or have someone document the system pressure during the afternoon when the system piping is hot (when the weather is >85-95F). You might find 95 psi in the morning and 250-300 psi or more at 3-4PM. I identify and resolve excessive pressure problems on a very regular basis!

Good Luck!

 

[ContractorDave]

Actually Sprink09 nailed it on the head - as it were. There was some poor insulation around a roof penetration and it got cold enough to create a bit of ice in the 1/2" sprinkler fitting at the 1 x 1/2" which was enough to scour the teflon seal off the seat and cause the head to leak as opposed to breaking it all together.

Thanks to the Viking Technical Support people for being very helpful when I was thinking they might be otherwise, given the CSC debacle.

Regards
Dave