I would like to know is there any clause in ASME / AWS / API regarding number of repairs allowed at one particlular section for carbon steel materials.

The situation is like this.

The contractor has performed a welding on a aboveground storage tank (API 650). After inspection by RT defects were found. Contractor was asked to repair. Another RT was done but defects were found AGAIN.
HEADACHE!
1. Should contractor be asked to proceed with another repair on the same plate of material
2. Proceed with change to another fresh plate. There is people concerned with the material metallurgical characteristic changes.
3. Revalidate WPS / PQR / WQT etc

I'm unaware of any limitations set forth in either ASME or AWS Codes but cannot speak knowledgably about API Codes. What I've found from my own experiences is these limitations are normally found in Project Specifications and are logically based around alloy type and service expectations.

Dear
All codes is only minimum requirement.
In ASME in all section FOREWORD said " The code does not address all aspect of these activities and those aspects which are not specifically addressed should not be prohibited. The code is not handbook and not replace education, experience and the use engineering judgments".
Now, all repair limitations is because type base metal.
For example in ASME section VIII Div1 part UHT-83 said Cautionary Note: "The properties of the base may be adversely affected by excessive heat inputs".
Because, UHT is for material Q&T steel.
Because, repairs is excessive heat input.
Other, API 1104 said" only 2 repairs, no more".
I think "The repair shall be done accorded a base metal"