Pipeline corrosion and integrity inspection without smart pigging? 1

DCVG abd CIPS using the CP system is very good at locating coating breakdown / cp leakage which is the precursor to external corrosion and is really cheap.

But for internal corrosion and wt determination smart pigging is the normal way.

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

Easier doesn't mean cost effective, but try a Google search on the term 'NACE ICDA' to see whether there are possibilities for your situation.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.

A pressure test is pretty cheap and easy....

Only as good as the day it is done but "proves" the integrity.

Can be done in product if you've got high confidence.

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

Without the IP, the integrity assessment is not deemed complete. In addition to what has been give above? Have you tried the checking on the probes and coupons..and the sampling analysis? Or perhaps a quick check using modelling tools,?

CH. Lee, PhD P.E
Lead Materials and Corrosion Engineer
Intecorr Consultancy
twitter.com/intecorr

@LittleInch, as you mentioned: "Only as good as the day it is done". Some companies substitute rigorous inspection with pressure tests and normally get a leak after a week or two and then started jumping around "but we pressure tested it and it was fine"!!!

Indeed and also depends on the test pressure compared to max operating. Many only do in service tests to design pressure or 1.1 x MOP.

Pressure close to MOP is not really proving anything.

But we got no response from the OP so will never know.

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

Pressure testing has mixed support. There was an argument against it because it could cause growth of subcritical cracks. So , theoretically , several pressure tests could grow a subcritical crack up to critical size. And , at least in older steels , there was "strain-age-embrittlement" . Where near a sub-critical defect ,there could be plastic deformation during a pressure test, the strained metal would loose toughness with time ( years ). I tested steels made in the 50 and 60's ( from failures of old pipelines). By cold rolling them 5 % then aging at about 300 F for 24 hr, then doing Charpy tests. Some steels showed a significant loss of toughness. And ,yes, you can say that is not what really happens in a pipe.

The 1.1x is standard for marine propulsion boilers. Then again, tube failures during operation are common...

LittleInch said:

A pressure test is pretty cheap and easy....
Only as good as the day it is done but "proves" the integrity.

Click to expand...

You omitted the operative word for pipeline pressure testing - 'quick'.
The petrochemical world found that out the hard way after many failures of ERW pipe with pre-existing flaws.
Which is why I will never trust mill pressure testing alone when specifying welded pipe.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

I would recommend going to 'NACE ICDA', just google it and you will find it!