Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Inspections on wrapping of a pipe line after a shut-down 1

Status
Not open for further replies.

Crude_Eng

Mechanical
Apr 24, 2024
2
Good day,

I'd like to find out if anyone has experienced a similar situation and has some advice. There is a line on the plant that is currently wrapped. The wrapping was done on the run and at temperature. Initially, the line was meant to be replaced at the next shut down, but was then de-scoped and then moved to the following shut down.
Does anyone know what inspections on the wrapping should be done when a wrapping goes through a shut-down and start-up scenario? The line will be out of service for about a month.
I have tried ASME PCC-2, but have not found anything with these specifics.

TIA.
 
Replies continue below

Recommended for you

"Wrapping" is rather vague.

Any details?
Photos?

If this is supposed to be an anti corrosion coating, then a spark test is usual to find the holidays or gaps in the coating.

You often also see pull and peel/tear tests on the coating to make sure its sticking to the pipe.

Normally a good coating or wrappping is only as good as the surface preparation....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
This sounds like a pipe that was wrapped with a repair tape.
 
Does anyone know what inspections on the wrapping should be done when a wrapping goes through a shut-down and start-up scenario?

IMO, this is a good question to your Maintenance team to answer based on the plant guidelines. I suspected that there was not an inspection requested if the wrapping was initially intended as a temporary cover for a short period of time.


 
Thank you very much for the responses.

The wrapping was done to the pipe due to low wall thickness and wrapped as per ASME PCC-2 allowance.
The main concern is regarding the temperature cycle that the wrapping would experience which was not initially intended/designed for.

LittleInch, I will attempt to get some more information on the specific wrap.
mk3223, the intention was meant to be a short term repair, but it was now decided to not effect the repairs now, but at the next opportunity.

As a precaution, I would like to know what inspection/s can be done to ensure integrity of the wrapping after shutting down of the pipeline to ensure a leak free start when the pipe is re-commissioned.

Thank you for the replies, looking forward to the further engagement.
 
Ah, more data is always good.

Do you mean something like a clockspring fibre wrap? Like this?
I think these are very vendor dependant so you need to drag them into the inspection and see what they say. Then they get a bit more interested if you've operated outside their envelope and might withdraw what ever "guarantee" they've given you.

The biggest issue for me is how can you measure what is left of the original pipe?? Most of these fibre wraps are only intended to provide strength assistence to non penetrating internal or external corrosion. If your damage was internal corrosion what has happened since? External corrosion maybe not an issue.

I don't know of any further inspections you can do to this type of wrap as it basically sets due to the action of the fibres and the epoxy.

Or you could rip it off and apply a new one?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Assuming it is some sort of Engineered Product, then the vendor would have done a design for the specific wrap that was performed. The answer becomes - talk to the vendor.
If it is something that the owner has installed as per a manual, then the owner is on-the-hook to be the designer / they would need to provide the advice, which basically becomes you unfortunately.

There isn't much inspection you can do other than visual to see any obvious issue, in particular I would be worried about the bond of the wrap to the pipe, any signs of this failing would be a no-go for me.

The other side is the question of consequence of failure. If it's a water line, the doesn't have any impact, I wouldn't be too worried. If contains a flammable / toxic fluid / or a leak will result in major plant outage, Then I would do everything possible to inspect and also escalate the risk / decision to the right person in the business (noting that the original engineering advice was "you can install this now, but you must cut the pipe out in the shutdown"), getting a operations manager to actually sign a bit of paper that says it might fail in service and they are happy to accept consequence usually results in a change of attitude.

Andrew O'Neill
Specialist Mechanical Engineer
Australia
 
The issue being questioned seemed to be one of adhesion when subject to thermal contraction and consequential expansion after the shutdown.

These wraps are usually quite short? Some more info on length, temperature and vendor would be good.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
LittleInch said:
"Wrapping" is rather vague

LittleInch gave you the answer, more information and a photo, would be helpful

regards
 
ISO 24817
Energy Institute- Management of engineered composite repairs: end user good practice guidance

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor