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Wet Sour Service 4

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ALA445

Mechanical
Jul 12, 2019
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AE
Dear Folks,
What are the requirements if I need to revamp a sweet service ASME pressure vessel into sour service. Please reply in the light of NACE MR0175/ ISO15156-1:2015.
 
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The requirements for revalidation will be:

1. Obtain a copy of ISO 15156 (all parts, not just Part 1)
2. Read aforementioned documents
3. Confirm that the vessel owner has consented to the application of the stipulated permitted exclusions where allowed, if not, move to 4.
4. Thoroughly review manufacturing records of the vessel
5. Ascertain that all pertinent materials, and welds, meet the requirements of the documents, paying special attention to clause 8 of Part 2, if not, move to 6
6. If the manufacturing records are non-compliant, think of ways to make them compliant; naturally, forgery is not a recommended option (again, watch out for Part 2, Clause 8 because it is well tricksy)
7. If the records are absent, sit down and think what non-destructive tests could bring the materials into compliance
8. Execute such tests
9. Review the results as per 5 (Part 2, clause 8 is still there, and it's not going away) (note: API RP 581 might help a little with the risk assessment as that is where you will be heading)
10. If it is still a problem, think about what destructive tests could be performed whilst still offering a chance of keeping the vessel
11. Either give up, or make sure you are not on the plant

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
Nice short list Steve. I have only ever been involved in one of these projects.
We went steps 1-5 and then 10. When they considered cutting panels out of the vessel for testing we immediately were put to work writing the specs for the new one.
Make sure that you also have any applicable owners specifications.

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P.E. Metallurgy, consulting work welcomed
 
Thanks for the great help both from SJones and EdStainless. At present scenario, No PWHT performed but not required as it is not a service requirement (UW-2), neither required in accordance with A-2.1.4 of NACE MR0175, not mandatory as per UCS-56-1 of ASME VIII Div.1. Carbon steel wetted steel not normalized and no HIC report for steel plates available. Qualification of welding procedure found without hardness testing as required by clause 7.3.3.2 of NACR MR0175. All we can do is to go for RT-1 which is RT-2 at present as shown on the nameplate and Data Report. What other NDT, DT do you suggest to bring the vessel into specs for Sour Service. Thanks again for the further help.
 
Prayer. After that, you have identified the shortcomings, so try to focus on the most serious damage mechanism: SSC. Susceptibility can be identified by hardness measurement and, wonderfully, there are devices available to do that. You just have to work out how many measurements and where. To support those measurements, you could consider getting some metallurgical replicas to gain an idea of the steel microstructure. They will also assist the HIC susceptibility assessment (alluded to above) as there is no nondestructive means of verifying resistance. Good luck.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
ALA445 said:
What are the requirements if I need to revamp a sweet service ASME pressure vessel into sour service.

Sounds like a new one to me.

Maybe a new internal lining instead?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
My question to Mr. Steve Jones in connection with my quote of Revamping of pressure vessel from sweet into sour service is:
If steel plates for shell and dish ends in fabrication of pressure vessel found to be ASME SA-516 Gr.70 with normalized condition, having maximum hardness less than 22HRC, forgings in accordance with ASTM A105 with hardness not exceeding 187 HBW, wrought pipe fittings used are ASTM A234 grade WPB then there are chances that we can use this vessel for sour service. How can we confirm these measurements with metallurgical structure using metallurgical replica and assess the susceptibility for HIC. Thanks again for your kind support.
 
If the original MTRs all show that those things are true, then it is down to validation of the weld procedures (fillers and resulting microstructure and hardness).
I don't believe that you can confirm these points without destructive sampling and testing.

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P.E. Metallurgy, consulting work welcomed
 
Look at the age, steel manufacturer, and composition of the steel from the inspection documents to assess whether features that will initiate HIC are likely to be present. Take replicas and/or some form of boat sample to try to verify presence or absence of such features. But, before you do all this, hire a decent integrity company like, for example, Becht, to help you out. Eng-Tips, interesting as it is, is not a Fitness For Service consultancy.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
We are having similar issues with one of the tanks that is being "planned" to shift process from slightly sour to extremely sour. The tanks are extremely old, but are generally in good shape and well-preserved, but the steel is not HIC-resistant and we do not know anything about the welds!!!
 
Corroneer, Makes me wonder what your insurance Co would think of that? Sounds like some serious risk assessment needs to happen.

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P.E. Metallurgy, consulting work welcomed
 
Ed - tanks will be a permitted exclusion from ISO 15156 if the end user so wishes. I've been involved with many a tank build for crude having neither restricted hardness control of welds, nor HIC tested plate, and there's been no cracking in the 32+ years I've known of a lot of them. Pitting and holes in the floor and shell, yes, cracking no.

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.
 
ISO 15156-2, Table 1, Page 2, Row 3 "Crude oil storage and handling facilities operating at a total absolute pressure below 0.45 MPa (65 psi)" Should fit most above ground storage tanks.

Steve Jones
Corrosion Management Consultant


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