Fin fan cooler leak from strength weld (tube to tube sheet)

[Kannn]

Hello engineers , i have a leak from a fin fan cooler , its type is plug type fin fan air cooler , the leak is from the strength weld between the tube and the tube sheet ( the strength weld had failed ) , i want to elimnate the leak , i know that plug will not be that sufficient, is there any way that i can repair this , like an expander to enter inside the water box and expand the tube , attached images for illustration

https://files.engineering.com/getfi...ile=2c1c703a-34c6-479d-b362-2483b48ac64d.jpeg

https://files.engineering.com/getfi...ile=76134a4a-32e4-47e8-af5a-dbd4e4379e68.jpeg

Waiting your support and help
Thanks

 

[EdStainless]

Ream the tube ends and remove it.
Then weld plugs into the holes in tubesheet.

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P.E. Metallurgy, consulting work welcomed

 

[Kannn]

The access for the tube from the waterboox is so hard , attached image for pluge type air cooler bundle , is there any special tool to do that , to expand the tube !

https://files.engineering.com/getfi...841-49d6-9df1-589c6a8581fa&file=IMG_3167.jpeg