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

• May 9, 2019

• #2

IFRs

Petroleum

Nov 22, 2002

4,682

US

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.

 

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• May 10, 2019

• Thread starter
• #3

jor1492

Mechanical

Aug 3, 2015

106

PA

Thanks IFRs,

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

thanks

 

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• May 10, 2019

1
• #4

IFRs

Petroleum

Nov 22, 2002

4,682

US

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

 

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• May 10, 2019

• #5

dhengr

Structural

Sep 22, 2009

4,669

US

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.

 

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• May 16, 2019

• #6

weldstan

Materials

Jun 24, 2011

2,808

US

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.

 

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