Weld a support plate over the horizontal and vertical welding lines a tank. 1

[jor1492]

Hello all,
I want to know if it is common to weld support pads on the tank shell , if the welding lines are over the welding lines of the tank.
if it is not possible what is the reason?

see attached picture.

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1557444185/tips/example_zgl3av.pdf[/url]

thank in advance.

 

[IFRs]

For API 650 tanks, it depends on the grade of steel that the shell plate is made of. If you can avoid crossing butt welds that is best.

 

[jor1492]

Thanks IFRs,

the tank is ASTM A36. Do you know if API 650 has information about this?

thanks

 

[IFRs]

See API 650 section 5.8.1.1
For your tank it is allowed but it is still not the best practice.

 

[dhengr]

Jor1492:
I don’t have a copy of API 650 in front of me. But, normally it is not good practice to weld into or across other welds because of the potential for intersecting high residual weld stress in the welds and the HAZ regions of the welds. These residual stress fields are perpendicular to each other and lead to nasty tri-axial stress conditions. Additionally, you want to be careful not to leave any start/stop stress raisers in these areas. Obviously, there are times when these types of conditions can not be avoided, and they need special attention to details.

 

[weldstan]

The material of the tank is A-36. API 650 permits tanks to be manufactured with A-36 in certain cases. Whereas you do not seem to know to what Code the tank is designed and manufactured, I suggest that you find out. Tanks can be manufactured to other Codes/Standards.