Relation between Minimum Leak Path and Minimum weld throat for Tube to tubesheet joint

[kunalsj]

Hello,

I need to establish a relation between minimum leak path dimension (Section IX) and minimum weld throat (Section VIII Div-1 UW 20) for Tube to tube sheet joint. Does anyone have any literature pertaining to it?

Thanks,

Kunal

 

[metengr]

For tube to tubesheet weld joints, the leak path is determined based on an understanding of loads on the weld joint. In some cases, the leak path will be the throat dimension of the fillet weld, if one is used. The leak path in a partial penetration weld can be determined based on anticipated loads in service.

 

[kunalsj]

I have calculated the minimum required throat as per UW-20 sketch (d) full strength joint, but I am not able to establish a relation with the minimum leak path and the throat. The ASME Section IX requries "minimum leak path dimension required by the design".

Thanks

Kunal

 

[metengr]

So, for a full strength weld joint under the service conditions for a tube to tube sheet weld joint, what are the failure modes to consider - tensile, shear ?? Based on this, you can decide on the leak path.

 

[kunalsj]

Considering the welds are subjected to tensile loads equal to tube strength, how can we establish the leak path?