Rank: Forum user 
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Hi Guys, I need a little here. The bulk of our fire water lines on our site are above ground and not lagged or heat traced so we have been having trouble of late with smaller lines freezing up on us. I have heard that you can get a circulation pump fitted so as to keep the water moving in bad weather?
It is a ring main we have so maybe that would need to be changed??
Any replies/help would be great on what it is we could do here.
I know that heat trace and lagging is very expensive for the amount of pipe we have so looking for alternative.
Thanks.
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Rank: Super forum user 
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The benefit of a ring main is that it is easy to do maintenance/repairs whilst still keeping the supply live for the rest of the ring, so backing away from that arrangement is likely to be a retrograde step.
How often is the weather in your area cold enough for long enough to produce freezing in the smaller lines? If you do get a freeze, how badly degraded are your fire fighting capabilities? How essential is this capability in the areas that may be affected, given the probability and severity of fire that you expect? What is the maximum size fire (in monetary and business continuity terms) that you can stand? Given a small-pipe freeze-up, could you exceed that?
Once you have the answers (nobody here can tell you) then you will be in a much better informed position on whether to spend the money on trace heating/lagging.
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Rank: Super forum user 
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i think there is an anti freeze you can add. That's from very deep in my memeory and all I remember.
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Rank: Forum user
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stuff4blokes wrote:The benefit of a ring main is that it is easy to do maintenance/repairs whilst still keeping the supply live for the rest of the ring, so backing away from that arrangement is likely to be a retrograde step.
How often is the weather in your area cold enough for long enough to produce freezing in the smaller lines? If you do get a freeze, how badly degraded are your fire fighting capabilities? How essential is this capability in the areas that may be affected, given the probability and severity of fire that you expect? What is the maximum size fire (in monetary and business continuity terms) that you can stand? Given a small-pipe freeze-up, could you exceed that?
Once you have the answers (nobody here can tell you) then you will be in a much better informed position on whether to spend the money on trace heating/lagging.
The weather has been bad since early November, we have had an 8" valve on our line rupture over the christmas and quite a few 4" valves (did not mention this earlier). The pressure switches at the fire pumps also froze, so at one point we had no fire fighting capabilities and with a fairly large amount of methanol on site it was a bit of a worry.
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Rank: Super forum user
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Depends on your situation, but on ships trading to arctic waters the norm is to drain the system on the basis that there is always someone on watch who can activate the fire pump when necessary.
System would need to be thoroughly drained, with no dead legs at the lower points which cannot be drained.
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Rank: Forum user
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Hi Torres,
We use an Alternative system which is charged with air during the cold winter months and water in the warmer summer months.
Is this something that could help you?
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Rank: Super forum user 
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Torres,
I can remember the last time I worked on sprinklers we had this issue and went over to air filled in the cold winter months, (25 years ago ish!) though we were not such a high risk by the sound if it! We were a manufacturing site, however, solvents and paint on site along with hot working.
I guess it would depend on the time to release extinguishant onto a fire in a dry system?
I have a friend who maintains the sprinklers at his place of work and they "go dry" in the cold months.
Perhaps the dry suggestions may be worth looking into!
IIRC you fill with compressed air and you need a drain at the end of every dead leg to allow the water out?
There may be some mods needed and a compressor to be added, also for the first few seconds of any actuation you would be "adding air into the fire"?
An 8" and a few 4" lines are not really small are they, I thought you meant a few 1" lines to heads!
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