Thermal pressure cycling in buried pipe
Thermal pressure cycling in buried pipe
(OP)
Does anyone have experience with pressure dips in buried pipe - we are looking into the possibility it is based on 'cold' ground and pipe. The fluid is moved from aoveground tanks thru buried piping to remote stations, and occasionally it is held below grade (such as shutdown overnight). When it is held, the pressure drops considerably. It appears this is the fluid cooling. Has anyone seen this happen before?





RE: Thermal pressure cycling in buried pipe
Amongst other things, coatings don't tend to hang on if the buried pipe is moving relative to the earth... corrosion wont be far behind when the coating goes.
Cheers
Rob
RE: Thermal pressure cycling in buried pipe
RE: Thermal pressure cycling in buried pipe
RE: Thermal pressure cycling in buried pipe
RE: Thermal pressure cycling in buried pipe
What makes you think that there is not a leak in the pipe underground?
StoneCold
RE: Thermal pressure cycling in buried pipe
StoneCold, leak is the concern. However, we believe there is no leak as (1) the recent pipe pressure test was successful (2) the pressure rises in the morning as (we assume) the ground heats back up.
I've been trying to figure out how to estimate if this heat loss is corrolated to the pressure drop, but unknowns like air entrapment make it difficult. Is there a rule of thumb anywhere? This is a kerosene-based fluid.
RE: Thermal pressure cycling in buried pipe
Vista Research, Inc.
755 North Mary Avenue
Sunnyvale, California 94085
I took a look on their website where I downloaded the document years ago and I could not see where they have it posted. You could contact these folks and see if they will email you a copy.