Welding sequence for shell-annular

[TANKO]

Good Evening to all
i'd like to have a clarification.


Does API650 provide that for the welding annular-shell you have to start from the inside of the tank and not from the external?

thank you

regards

 

[IFRs]

Depends on the NDE that has been agreed upon.

See API 650 7.2.4 which includes this:

7.2.4.1 The initial weld pass inside the shell shall have all slag and non-metals removed from the surface of the weld and then examined for its entire circumference both visually and by one of the following methods to be agreed to by Purchaser and the Manufacturer. If method “a” is applied, either inside or outside weld may be deposited first. If method b, c, d, or e is applied, the inside weld shall be deposited first.