Failure on Frozen Piping
Failure on Frozen Piping
(OP)
I am not familiar with failures due frozen conditions. Currently I am performing an assessment for a piping failed due frozen condition, and I would like to know how I can get the maximum pressure developed during the frozen process until piping gets the burst pressure.
Im was wondering if the piping material gets brittle and it contributes to the failure, or it is an additional factor ?.
The failure happen in a SA 106 3" piping.
Thank you in advance for you support
Regards
leont
Im was wondering if the piping material gets brittle and it contributes to the failure, or it is an additional factor ?.
The failure happen in a SA 106 3" piping.
Thank you in advance for you support
Regards
leont





RE: Failure on Frozen Piping
Answers here might help you to guess what might have happened in your system. Continued freezing of liquid water trapped between two initial ice plugs seem like a plausible explanation, given that ice contracts with further temperature decrease once below the freezing temperature.
ttp://www.newton.dep.anl.gov/askasci/eng99/eng99358.htm
RE: Failure on Frozen Piping
RE: Failure on Frozen Piping
This makes inspecting for affected areas fairly easy. If the pipe is visible and has been painted, there will be long, longitudinal cracks in the paint -- pipe has swelled some, paint didn't. Swelling can be confirmed using dial-calipers. My examination of freeze splits has shown them all to be ductile, rather than brittle fractures.
RE: Failure on Frozen Piping
RE: Failure on Frozen Piping
David
RE: Failure on Frozen Piping
Thanks!
K
RE: Failure on Frozen Piping
RE: Failure on Frozen Piping
On the topic of ductile vs brittle... If a water pipe was exposed in say a -40° environment and the flow was stopped, the water would freeze at 32°F / 0°C. The loading on the pipe is now determined. At this point, the pipe is ductile. But as the pipe and ice continues to cool towards -40°, the pipe may become brittle. Could we see a situation where the pipe sustains the load in a ductile regime but ultimately fails at the same loading when it becomes brittle?
jt
RE: Failure on Frozen Piping
it's true that I'm in -10 right now, but it doesn't mean that you can expose me to -40 environment and stop the supply!
regards,
waterpipe
(just to refresh your minds!)
RE: Failure on Frozen Piping
I'm in about 50°F now. I assume your -10 is in °C?
Inadverdent stuff happens. I've designed a temporary repair for an air cooled heat exchanger header which was
hydro-ice-tested. As far as I know, the piping didn't suffer, but then, I wasn't on site. This was in a location which averages 8°F / -13°C ambient air temperature in the winter. Exposed metal can get a bit cooler with radiative losses...But, that doesn't change my question above!
jt
RE: Failure on Frozen Piping
Thank you so much for so professional answers.
Waterpipe, that paper tells me everything about the technical causes of these type of failure.
Thank you much
RE: Failure on Frozen Piping
RE: Failure on Frozen Piping
RE: Failure on Frozen Piping
3% of water on Earth is freshwater, 2/3rds of that is ice.
I'm sure anyone reading this thread will find these additional facts about water useful, if just not plain interesting,
http://www.chem1.com/acad/sci/aboutwater.html
Don't miss this part of the page,
http://www.chem1.com/acad/sci/aboutwater.html#ANOM
RE: Failure on Frozen Piping
The experience I have regarding freezing condition was a designer who had assumed that water wouldn't freeze in a pressurized pipeline because of the pressure! So there was no provision for freezing of an exposed 25 bar pipeline (relatively high pressure in water works) connecting surge tanks to the main line. Obviously he had not seen the charts provided by BigInch and was not aware about the "weired" behavior of water. This ended up to an extra item for thermal isolation of the connecting pipeline with heater jackets.