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How to establish a corrosion database for pressure equipments 2

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etsen

Mechanical
Sep 11, 2006
67
How to establish a good corrosion database for pressure equipments,such as pipes and pressure vessels? I am not sure about that. Could anybody have a good method or practice to recommend? Thanks.
 
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etsen;
I am not exactly sure what you are asking. If you are trying to create your own database unique to your process conditions for your own equipment, I would develop an excel spreadsheet by component and track inspections (Nondestructive testing and thickness readings)over time.

If you want to obtain general corrosion rates for various materials close to your process conditions, this data is probably available in various reference books on corrosion of materials.
 
Try to look for an off the shelf software package that meets your technical needs. Trying to establish an inspection database yourself could prove to be a painful exercise.




Also, try a Google search on PACER corrosion management, Cortran, Tischuk OCA etc, etc,

Steve Jones
Materials & Corrosion Engineer
 
in my former life in the power generation industry we implemented an inspection plan to monitor the health of our steam plant.

we broke down our plan into various systems:
high energy piping
boiler
heat exchangers

high energy piping started with identifying any piping system that had seamed piping. each year we would take a zone (section) and perform UT on the seams. this took us approx 5 years to complete that system. then we started the cycle over again comparing previous results. on suspect areas we also performed dye penetrant and/or metalurgical replications.

boiler was broken down into the various heating sections, waterwalls, reheater, economizer, superheater, steam drums, and headers. same process as high energy piping except it only took us 2 years to complete the inspection cycle.

heat exchangers included feedwater heaters, deaerators, etc.
same inspections as above.

after each inspection the contractor(s) we used provided the results from their inspections, most times in an electronic format, spreadsheets mostly, and we could begin to track corrosion/erosion rates based on the comparisons.

final results were implemented into a plant life extention program that extended the safe operation of our units.

good luck
 
API 580 / 581, risk based inspection.
If you mean to assess the likelihood and consequence of failure (risk) of your plant (equipment and piping) this is the best way to do it. there are modules for each type of corrosion mechanisms to establish the likelihood and type of inspection.
there are several software that allow you to create the database of equipment / assess the risk / create an inspection plan and manage the inspection /ndt activities.
The software suggest by sjones, amulet, can do all these tasks.


S.

 
I gave up on the annual inspection of the same point on piping and vessels. All I ever got was a random number generator, exactly what SPC states.

Instead, I use the original risk based maintenance (kent Mulberry's from Dow Chemical "Risk based pipeline ..").

I take readings from areas I know corrosion will be the most likely. Then look at the data and compare to original pipe data to detect corrosion and evaluate the time until next inspection. I also analyze the probabillity versus consequences of failure to adjust inspection intervals.

Its all done in a work book in excel..\ All the evaluation and calculations. the sheet evaluates and prints warnings along with next inspection date.
 
Thank everybody for providing so much advise. To dcasto: How did you arrange the same points on piping and vessels for inspection (thickness measurement for calculating corrosion rate?)? Take a gasoline hydrogenation reactor for example, which would you do? I saw a worker measured thickness through a hole in insulation of piping and put some insulation into the hole after that in a refinery, which I think may be not appropriate for the hole full of insulation may increase the corrosion rate. I am right? Could you like to recommend some good or appropriate practice or reference books for RBI?
 
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