Condensate and Aqueous Tank

[zhamal]

Material type A516-60+ S5, 1 st shell. From inside of the shell there are pittings. Thickness 16 mm. Tank is almost ready to Hydrotest. Ponton type tank.Any solution to this problem? Thank you.

 

[Jay_]

If this is a tank in service, you can find the acceptable criteria in api 653. I forgot the clause number so you gotta search in the first few pages.
If this is a new tank then you made a mistake accepting this kind of material,
what is the depth and diameter of the pits?
What is the required thickness, nominal thickness, corrosion allowance and design code.

Detailing is a hobby,

 

[MJCronin]

Let the third world guessing games begin !!!

After many many questions, and much wasted time we will finally arrive at a complete description of the problem ...

"Tank is almost ready to Hydrotest" ..... This means a new tank to me !!!

You purchased defective pitted materials, did not inspect the materials when delivered and are now searching for a fix.

Cut out the defective plates, replace with new inspected plates and fire the guy who was supposed to inspect new purchased materials



MJCronin
Sr. Process Engineer

 

[r6155]

I don't think it's pitting. I've seen worse things than this. Depending on the extension it can be easily solved with a grinding wheel and repair by welding if required.

Regards

 

[r6155]

When you take such a photo you should put a tape measure to get an idea of the actual dimensions.

Regards

 

r6155,
I agree it is not pitting, though I'm not sure about the first pic.

Pre-service inspection just became an in-service inspection.

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

 

[r6155]

ironic metallurgist
It can be during rolling. The rollers were not clean. Who knows?

Regards

 

[Dhurjati Sen]

I completely agree with MJCronin.

Regarding the defects, I suggest Mr Zhamal does not waste much time and take corrective action at the earliest to finish off the project.

Repairing such pits with grinding and subsequent weld build up would be highly time consuming.

DHURJATI SEN
Kolkata, India

 

[r6155]

As I said 03 Aug 20 20:24 “ Depending of the extension…..”
For a new tank pitting is impossible because fluid environment not exist. "Metal loss" is correct, instead of "pitting".
See “metal loss” in API 510 and 579

Regards

 

[Dhurjati Sen]

We do not have any history reg. the storage / age / mode of transportation of the subject plates.

All of the above can always lead to such "metal loss" as per API but old fashioned guys like me would always refer to them as pits.

API and other codes exist today because of contributions of people like us.

DHURJATI SEN
Kolkata, India

 

[MJCronin]

C'mon guys !!! ....... You know how this third-world game works !!!!

We have only asked just a few questions so far !!! ...... We need to ask at least 15 to 20 more questions and then waste a lot of time as the original poster is very, very busy and will, of course, ignore all advice and responses.

Furthermore, these pictures are way TOO CLEAR ! .... zhamay should have taken them from at least another 100 ft back

zhamal, speaking for all of the others on this forum, We think that your tank/vessel/whatever is just fine.... even with those massive pits. You should just deliver it to your ultimate customer and demand immediate payment.

If they have any further questions, just direct them to this thread ...

Zham, please spread the word .... You and your peers should always come to a group of nameless, faceless engineering strangers, demand help and then ignore the solutions

Have a nice day ....

MJCronin
Sr. Process Engineer

 

[r6155]

@ Dhurjati Sen
It is time for you to use the correct words that others have defined in the standards and thus thank them for their work.

Regards

 

I don't often order steel, but when I do it tends to be from N American & European mills.

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