Earthing for a cross country pipeline

Daktor · May 1, 2013

Hi,
Being a mechanical engineer i must apologise for my lack of electrical knowledge however i have a issue that i hope someone here can advise me on please.
I am designing an aluminium cross country pipeline that is going to pump water. It is raised off the floor and has aluminium victaulic couplings. Its is fed from a pump which will be earthed, however does the pipeline need to be earthed itself ? When i have built these before to pump aviation fuel it has been earthed however will there be some legislation saying that it needs to be earthed for pumping water too?

If it does need to be can someone please point me to the right regulations so i can include it in the design tasking folder. I have a IHS account so i can access most guidance and legislation documents.

Thank you very much

Marvo · May 1, 2013

I'm not sure what your UK regulations require but I would specify earthing on the grounds of preventing/reducing corrosion regardless of electrical requirements.

Daktor · May 1, 2013

As in cathodic protection?

Would that be necessary in aluminium though ?

Thanks for the help mate

Clive P · May 1, 2013

Hi,

I worked ( not designed ) on gas pipelines for many years. Where the pipeline was above ground and was in any way connected to the electrical network, then yes, the pipework would be earthed. At the point where the pipework went underground ( via insulation joints ) it had to be protected by Cathodic protection. As you are working with Aluminium then I would imagine that environmental factors would also need to be taken into account. Designing pipework protection is generally deemed as a specialist subject, probably best to contact a company that specialises in this type of work.

Regards.

Engineer54 · May 1, 2013

As Marvo pointed out, long cross country pipe lines of several miles, will need a corrosion assessment to be carried out. Actually earthing a pipeline of this type can actually accelerate corrosion in certain circumstances. This depends on the soil types and conditions encountered along it's route. Also you may need to take into account any HV power line towers, you really don't want to run parallel too close with them for any distance, induced voltages can be huge, but then i'm only talking from experience of long large (4 meter diameter) underground pipes.

As an initial step i'd contact pipeline specialists, to get all the requirements you need to follow on your installation. It's not really a subject that can easily be advised on, ...on an electricians forum!!