Pipe freeze analysis
Pipe freeze analysis
(OP)
When water pipes freeze, how do you analysis the forces and pipe stresses from the phase change?
Anyone have links to online reports or analysis?
Anyone have links to online reports or analysis?





RE: Pipe freeze analysis
at 1ºC Water density is 999.9 kg/m3 SVw = 0.0010001
at 0ºC Ice has a density of 917.0 kg/m3. SVi = 0.0010905
pi D^2/4 / pi/D = ratio of volume to circumference
That's about a 10% increase in volume. The stress generated in a pipe icreasing in diameter. The pipe is getting a little smaller too as it decreases circumference by 0.000012 mm/mm-Cº
When you do the math you'll find out its enough to rupture most pipes.
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RE: Pipe freeze analysis
Regards
RE: Pipe freeze analysis
at 4ºC the SG of water is 1.000
at 1ºC the SG of water is 0.999
at 0ºC the SG of water is 0.999(8)
at 0ºC the SG of ice is 0.917
Water specific volume differences between 0 and 4 degrees probably isn't going to hurt the pipe, but the phase change does. You won't notice any difference in the calculations if you use either 4 or 0, as its during the phase change that 99% of the density difference between water in the liquid phase and ice in the solid phases takes place, which explains why ice floats.
To be technically correct, the initial temperature should be taken as the temperature at which the container is sealed, not 4ºC.
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RE: Pipe freeze analysis
Ted
RE: Pipe freeze analysis
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RE: Pipe freeze analysis
Brian
RE: Pipe freeze analysis
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RE: Pipe freeze analysis
I tried websites-with no success- to find compressive stress (pressure) vs density for ice. Knowing that piping/equipment can/do fail under freezing conditions, it still should be of interest to find effect of ice stress during freezing. While I'm not a structual/civil engineer, the effect should make a good technical paper.
Regards
RE: Pipe freeze analysis
Sailo,
Search for the "bulk modulus" of ice, for which I found the value of 2E9 N/m2, strangely enough being used in conjunction with estimating the stress in a freezing engine block, here
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