Piggyback pipeline (HPHT) with High Voltage power cable
Piggyback pipeline (HPHT) with High Voltage power cable
(OP)
Has anyone ever design or install pipeline with piggybacked High voltage power cable? If yes, what is the limitation?
We have one HPHT pipeline (171 bars design pressure and 150 degC design temperature. And someone wanted it to have high voltage power cable to be installed piggyback with that pipeline.
We have one HPHT pipeline (171 bars design pressure and 150 degC design temperature. And someone wanted it to have high voltage power cable to be installed piggyback with that pipeline.





RE: Piggyback pipeline (HPHT) with High Voltage power cable
I find it difficult to believe that the od temperature of the pipe is 150c. A few more details would help.....
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RE: Piggyback pipeline (HPHT) with High Voltage power cable
Is there any effect if the high voltage power cable to the pipeline as it is piggybacked to the pipeline. Like eddy current effect, interference to pipeline CP (sacrificial anode).
For the pipeline itself is not insulated, we need the pipeline temperature to drop as much as possible (reduce the lateral buckling issue).
RE: Piggyback pipeline (HPHT) with High Voltage power cable
Especially with an armoured cable, there are no electrical effects on the pipe.
Your issue is the cable size. Cables don't like getting hot and need somewhere to dissipate heat. Strapping it to a hot pipeline whatever it is is not a good idea for the cable.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Piggyback pipeline (HPHT) with High Voltage power cable
Additionally, I'd worry about vandals.
Mike Halloran
Pembroke Pines, FL, USA
RE: Piggyback pipeline (HPHT) with High Voltage power cable
What do you mean by piggyback?
RE: Piggyback pipeline (HPHT) with High Voltage power cable
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Piggyback pipeline (HPHT) with High Voltage power cable
RE: Piggyback pipeline (HPHT) with High Voltage power cable
There are probably many technical issues, and also safety concerns, for both utilities in placing at least very high voltage cables very close to very hot, high pressure transmission mains. [I visited an ongoing pipe bursting installation last week, and all was going well until I understand a worker jobbed a post hole digger into a power cable (at a daylighting location) very close to the old line being burst and replaced with new pipe. While no one was hurt, that kind of put a damper on that pull until the cable could be repaired.]
RE: Piggyback pipeline (HPHT) with High Voltage power cable
In the past, there are pipelines that now cannot be pigged because there were no provisions made for controlled lateral buckling.
Also, if both pipeline and HV cable are all wrapped up in concrete and HDPE, the cable could also reach 150degC - can the cable insulation handle this ? - the electrical engineer can tell you if this is permissible.
Both pipeline and electrical engineers need to be consulted for this one. There are many complications that a pipeline engineer has to work with when setting up lateral buckles on HPHT subsea pipelines, and piggybacking a HV power cable may make things more difficult.
RE: Piggyback pipeline (HPHT) with High Voltage power cable
RE: Piggyback pipeline (HPHT) with High Voltage power cable
However because of the temperature issue and the difficulty in laying both together, most systems would lay the cable separately and then bury it as cable ships can run very long distances very quickly and the cost of your cable is a lot less because it is thinner as it is cooler. On a piggyback the cable will need to be in the top half and thus is exposed to potential for damage.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.