Weldability of a API-650 tank constructed in 1980 3

[tankinspector88]

In the terminal I work we have a couple of tanks in need to be reconstructed, new bottom and in some we need to also substitute the first ring.
These tanks are operating more than 40 years, I'm worried about the weldability of the new plates with the old one.
Anyone can indicate a test or a lecture were I can get more information about?

 

[JStephen]

On that specific question, see 11.1.2 in API-653.
Usually, weldability isn't an issue on welded tanks, but may be on riveted tanks. If the tanks are "only" 40 years old, likely not an issue.

Normally, the need for work like this would involve a complete inspection per API-653. There are various courses available on application of API-653, also consultants who will do all the inspection and/or analysis.

 

[tankinspector88]

The tank was already inspected per 653, new bottom and new ring was the recommendation.
I'm worried about mixing new and old plates because I had bad experience welding patch plates in old tanks. The material seemed to crumble.
Thanks for you answer!

 

[Geoff13]

I 100% agree with what JStephen said.

I can't count how many tanks we've welded plates into. I wouldn't hesitate on tanks this young. On older tanks I still would go ahead as long as they weren't riveted.

I have never heard of nor experienced plates that "crumble". It sounds like a unique issue, not one generic to "old" tanks.

 

[MJCronin]

It is possible to "sting" a small section of the tank to confirm or deny the plate steel properties .... small fee involved

This could become very imporatant if there are later legal defenses ... to buttress an arguement about what was a reasonable and prudent course of action

MJCronin
Sr. Process Engineer

 

[FacEngrPE]

In the riveted steel plate era it was not uncommon for structural steel and plate to contain sulfur for easier drilling. High sulfur steel is known to be difficult to weld, as it increases the tendency to crack. hat to

https://weldingtech.net/high-sulfur-steel/

https://www.ispatguru.com/sulphur-in-steels/

If you do not know the material of your tank, have the tank material analyzed, then use that to ensure use of the correct Weld Procedure Specification.