Mortar Lined Ductile Iron Pipe - Freeze Protection

[pmover]

location - artic environment

mortar lined ductile iron pipe, ANSI/AWWA C150/A21.50

new pipe is buried @ roughly 4-feet below grade and several feet in length (a network of pipe).

unforeseen circumstances may force newly installed piping system to be exposed to winter conditions before hydrostatic testing/commissioning. unfortunately, the pipe has been filled with water.

a plan is being prepared to drain as much water from pipe as possible, but there are slight dips in pipe profile whereby not all the water may be removed.

question: anyone know if residual water left in a mortar lined ductile iron piping system that freezes (not a filled piping system) will have any impact on the mortar-lined pipe (i.e. cracking of mortar or otherwise)?

any suggestions to avoid freezing of water are welcome (i.e. circ pumps, glycol, alcohol, etc.).

 

[rconner]

While I have personally not done the testing to confirm this, my gut feeling is that it is not good to freeze any pipe material (at least not full of water!) While I don't have any experience with this either, I wonder if it might be possible to insulate over the line/slab/ground as much as practical, and maybe even also consult with a "pigging expert" to see if one could say propel e.g. a foam "swabbing pig" through the line with hopefully pretty low air pressure to force virtually all water out of the line before it is left to cool? If the latter is done, one would need to take safety precautions in dealing with compressed air including making sure there is adequate restraint for what pressure is to be applied over some safe length of piping near the line ends, and don't let anyone or anything stand in front of same!!

 

[rconner]

While I have personally not done the testing to confirm this, my gut feeling is that it is not good to freeze any pipe material (at least not full of water!) While I don't have much specific experience with this either, I wonder if it might be possible to apply some sort of heat tracing, insulate over the line/slab/ground as much as practical, and/or maybe even also consult with a "pigging expert" to see if one could say propel e.g. a foam "swabbing pig" through the line with hopefully pretty low air pressure to force virtually all water out of the line before it is left to cool? If the latter is done, one would need to take safety precautions in dealing with compressed air, including making sure there is adequate restraint for what pressure is to be applied over some safe length of piping near the line ends, and of course don't let anyone or anything stand in front of the ends!!

 

[pmover]

rconner,

thanks for the response. i concur regarding avoiding freezing of any pipe. the pipe is installed; hence, heat tracing is an $ option.

all,
also, i need to clarify that the pipe, while it may be filled with water now, the plan is to not have any water in pipe upon draining. however, there are low points along the pipe. also, the pipe has 2-inches of polyurethane insulation and the backfill is basically a mixture of small gravel and silt.

yes, we've discussed the pig option. frankly, i like the pig option along with using an air mover to help with the air drying process of the pipe system. followed up with some dry nitrogen and perhaps any freezing can be avoided.

again, anyone have any knowledge or first-hand experience with freezing of mortar lined ductile iron pipe - any impact to mortar?

thanks!
-pmover

 

[dicksewerrat]

Call some pipe suppliers in Minnesota and Canada. I can't believe they never stock pipe during the winter.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[rconner]

Just to clarify based on all new information provided (and the apparent sort of reframed questions). I am not aware of any problems in what I believe is probably many decades of storage experience of suppliers or municipalities of ductile iron pipe in even very cold conditions (my original comments were directed toward freezing of all pipe materials potentially full of water, that I took as the drift of the original inquiry).

 

[pmover]

thanks for the simple & effective suggestion! lets hope the pipe ends are not covered when stored outside . . .

rconner, sorry for any confusion and thanks for responding.

-pmover