Preinsulated Piping Corrosion
Preinsulated Piping Corrosion
(OP)
Does anyone have experience with preinsulated piping installed underground in a wet environment (high water table)? What materials are recommended for the insulation, conduit and outer shell?
Have you experienced ID corrosion of the steel conduit due to water ingress into the insulated annulus around the carrier pipe?
If so, what were the sources of the water ingress?
Have you experienced ID corrosion of the steel conduit due to water ingress into the insulated annulus around the carrier pipe?
If so, what were the sources of the water ingress?





RE: Preinsulated Piping Corrosion
www.t
The other problem with water ingress into the insulation is loss of heat. A foamed insulation reduces a the flow path considerably.
No matter how hard you try with steel there will always be apenetration of the insulation vapour barrier and corrosion will result leading to loss of availability of the asset.
RE: Preinsulated Piping Corrosion
RE: Preinsulated Piping Corrosion
I'm sure you'll get some horror stories posted here, but a steel sleeve pipe would be my default choice. It would take a long time to corrode through the sleeve from the inside - especially if you can seal it up well enough such that the 400 degree steam inside the annulus will evaporate any minor infiltration you do get.
Make sure you consider thermal expansion effects for the sleeve as well as the pipe. You have a 400 degree heat source. The only mechanism to remove heat is conduction through the soil, so it'll be pretty hot.
Greg
RE: Preinsulated Piping Corrosion
What pH & chloride, etc. of the ground water?
What is the ground & fill?
Once, on a totally different project (hazardous waste cleanup), I backfilled with crushed limestone to groundwater depth to convince a regulator nothing bad would happen (at least, before they retired!).