Ultrasonic thickness testing on steel tanks 1

[Clasan]

Hi Folks,
I have a confusion here about grid layout for thickness measurements around tank base walls.

I've seen a reliability technician marked letters from A to K following a pattern around the base walls of a CIL tank especially at the welded sections but couldn't work out what type of grid layout he is using.

Anyone with any idea about this?

 

[LittleInch]

Why not just ask him?

Any spot measurement is only valid for that spot so to get any idea of general corrosion you need a decent grid. How tight that grid is is up to the purchaser of the survey - you?

Or he seems to be concentrating on the areas where corrosion is more likely (HAZ) of the welds.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Clasan]

Why not just ask him?

Any spot measurement is only valid for that spot so to get any idea of general corrosion you need a decent grid. How tight that grid is is up to the purchaser of the survey - you?

Or he seems to be concentrating on the areas where corrosion is more likely (HAZ) of the welds.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

Thank you for your answer

 

[zelgar]

When I've seen shell thickness measurements, they normally will do one per cardinal direction (i.e., N, S, E & W) per elevation @ multiple elevations. Additional testing may be performed at areas where there may be damage/deterioration or where they want more details (e.g., individual welds).