Pipeline heating before backfilling 1

[FilippoT]

I need to install thick pipeline in very cold environment (-30C). Longitudinal stress due to thermal expansion (working temperature is 80 degree) is making the overall stress analysis non passing. Therefore we ere thinking to heat the pipeline after laying and before backfilling to reduce the thermal expansion in restrained condition and decrease the longitudinal stress.
Did anybody experience something like this?

 

[LittleInch]

It is pretty standard stuff in the Canadian bitumen fields where they use hot water flow over a period of time. It has also been used on trace heated pipework to pre extend the pipe by using the heating system before final closure and backfilling.

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[blacksmith37]

I think you need expansion loops to allow movement as the metal temperature changes.

 

[LittleInch]

See

https://www.researchgate.net/public...ed_Design_Versus_Preheat_for_Hotbit_Pipelines

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.