wrapping and coating of under ground pipelines

[ash68]

Hi guys,

How to confirm whether wrapping and coating is required or cathodic protection is required for a under ground pipeline.

regards

Ashok

 

[zdas04]

They are not mutually exclusive. With the quality of today's coatings and shrink-sleeves/tape a person would be nuts to bury uncoated pipe in any application.

As to cathodic, there are generally regulatory requirements for protection. For pipe that doesn't come under a regulatory requirement, company policies often require protection. Absent that, then it comes down to engineering judgement. I operated a non-regulated gathering system for a company without a policy. I looked at the protected pipelines in the area and opted for not installing cathodic protection, but I required test leads to be attached to any steel pipe that crossed someone else's steel pipe. I had those test leads evaluated annually and never had a stray current problem--maybe because of the quality of my coatings? If I had it to do over I would make the same call.

David

 

[BigInch]

We can't tell you that, as there are many factors that affect the pipelines external corrosion rate and you have not mentioned any one of them.

zdas, The lack of corrosion may have had something to do with the remoteness of the typical unregulated gathering system and perhaps also a soil with low activity levels. My old system didn't have one high voltage wire within 50 miles of it.

I would recommend that BEFORE you make a decision about about how you will handle corrosion, or not handle it at all, it would be far better to do a stray current survey and have your soils along the route analyzed too. Nothing worse than finding out after only a short time that what you thought was your steel pipe really looks more like the kitchen sponge. If you need some ideas about how to do that, contact these guys

http://www.corrpro.com/

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

 

[cvg]

a corrosion study should be done, although my experience with corrpro was that there standard recommendation is for cathodic protection without adequate risk assessment.

 

[BigInch]

Well.... I just said contact them for ideas on how to do a survey, but 99.99% of the time you're going to have some kind of CP anyway, so in that case they'd be rather helpful.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

 

[cvg]

for a petroleum line, I would agree with the 99.99% CP.
However, I deal mostly with water resources projects and rarely see cathodic protection being used. Wrapped, bagged, coated, bonded joints maybe and sometimes test stations for the larger, higher risk projects - but CP is probably only used in about 0.01% of public - water resources projects (at least in the western US).

 

[SJones]

If the local regulations and the pipeline code you are working with are silent on the matter, consult NACE SP0169

Steve Jones
Materials & Corrosion Engineer

http://www.oilandgaspeople.com/cv/11499664

http://www.linkedin.com/pub/8/83b/b04

 

[ash68]

Thank you guys for your prompt replies.

Regards

Ashok