Factors influencing weld toe to toe distance requirements

[ricellis]

We would like to cut out a 16mm butt weld on an existing precipitation tank, and place a new weld only approximately 100mm from where the old weld was. This is far less than that specified in API 650. We can test a sample of the weld and plate around the HAZ; do we need to look for metallography changes only, or are there other factors that influence weld toe to toe distances?

 

[unclesyd]

What is the material of construction of the tank?
What standard was the tank fabricated?

 

[ricellis]

Sorry, the tank was designed to API 650 and ASME section 8, it is grade 250 steel and the tank is 30 years old.

 

[metengr]

I would suggest you post this question in the forum below. Off the top of my head regarding adjacent weld toes , other than harmful residual stresses and potential sensitization issues with certain grades of austenitic stainless steels, if neither of these apply to your situation, I don't see why you could not perform this repair.

forum809