API 650 8th edition

[phinojosar]

But with API 650 available in 1992 you will only judge according to the parameters stated in the CONSTRUCTION of that storage tank, the inspection criteria is in API 653 that redirects you to API 650, so actually wouldnt you need both API 650 and API 653 that where available on 1992?

I had a client before that asked on contract that we judge the inspection according to ASME VIII from 1980, that was a pain in the ass to find but when the client requires it there is nothing to do.

Sorry but can't help you getting this standards, I asked a friend to search in the library of a local refinery to find ASME VIII that time because there where no digital copies.

Wish you the best of lucks!

[Marty Thompson]

Again, you go by the latest API 653, any repair acceptance has to be to the current, using the last edition of 650 if 653 doesn't cover it..
Unless you are totally rewelding all joints, you have to calculate the joint efficiency for hydro fill height servicability by the construction edition used.
Do you know how much RT they originally used. Are the LOF T's in the lower courses?
For 8th edition,
If they used Basic Standard RT, then joint eff. is 1.00;
If they used spot RT per Annex A, then joint eff. is .85;
If they used no RT per Annex A, then joint eff. is .70.

[Marty Thompson]

Yes, if the construction meets the original standard and no repairs are made, then it is grandfathered, but if you do repairs, it changes the game, you have to follow current.

[kgk092]

Actually here no one knows how much % RT they took at the construction phase.
The tank have been built in 1988 and put in service on 1993 since then it was opened first time for rehabilitation. Name plate says according to API 650 8th edition.

Now current scenario there we took RT on all vertical joints of 1st and 2nd shell (One spot in each joint) and all cleared, we shoot 8 spot in horizontal joints between 1st and 2nd shell. and all T junction of 1st and 2nd shell course as per client requirements. Now 11 out of 38 T's are having Lack of fusion.

So now client says it has been in service since 20 years and nothing happened to it so why we need repair? But being contractor API inspector I can not decide that.

So please throw some light on this matter "code says anything about based on continues service history we can accept this"

Big thanks to all of you..a

and waiting for your reply...

[Marty Thompson]

If this a small tank with 1/2" or less shell material that would have had Appendix A applied to it?
Your RT findings indicate that they did not RT at construction.
If so, then your fill height would be restricted by the joint efficiency factor of .70 in calculating any remaining thickness of the shell.

[kgk092]

Tank dia 60 meters
Tank height 14.867 meters
Design liquid level 13.6 meters
Shell thickness 19.7, 14.5, 12, 12, 8, 8
Shell material Astm A 633 Gr. C for bottom two she'll and remaining A283 GR C
Single deck internal floating roof

[Marty Thompson]

Well, it could not have been built to Appendix A, so the joint efficiency for that date by code is 1.0.
My question, why did you do RT? did you do any major repairs or modifications that would require hydrotesting?


The client/owner has the ultimate responsibility

EEMUA 159:
"When all repairs have been executed, the tank must be declared fit-for-purpose by a responsible staff member of the tank owner before the tank is allowed back in service."

API 653:
"The owner/operator has ultimate responsibility for complying with the provisions of this standard. "

[kgk092]

RT done as per contract scope of work. clients main intense to check for any ***** or major service oriented defects. Tank has been opened first time after 20 years and the condition is still excellent other then RT. We are in deep sit now as the UT confirms all the defects in back welds and floating roof position at exactly center of the weld joints. By taking E other than 1 the required thickness is exceeding the current shell thickness.

Anyhow Thanks a lot for your valuable contribution.

[Marty Thompson]

The roof can be jacked to make repairs, reduce the maximum fill height.

[kgk092]

yes that's true, but client does not have money!!! they are not willing to pay anything extra, even reducing current scope as oil prices marginally low now.

I have suggested them considering no RT taking E=0.7 reducing the fill height... waiting for their reply...

[kavita_00]

I found one code related to the topic. Hope you will find it useful.

[kgk092]

[link Point to another website Only the registered members can access]
As per this clause it does mean that we shall Radio-graph the weld joints??