My company dispatched my apprentice and I to an oil processing plant on the west cost for a crack repair on an oil heater treater. When we arrived in house staff was pulling this E-tube out and washing it for us. During the first inspection inspections a small crack on the exterior side was noticed on the toe of existing weld. After pulling washing and reinspecting a 21” crack was discovered on the back side.
I had E-tube propped up in the best possible position for ease of access on all sides, CARBON ARCED out the crack on backside . (1/2) deep and a total of 25 “ two inches past the the crack and welded her up with 7018 1/8 .
Next day came back gouged out the front all the way down to sound metal and welded it up on the 3rd day.
Front cracks was just as long as the front crack but dug in a lot deeper.
Base metal 515 grade 70 / 1-1/4 thick.
CAC made short work of joint prep. Joint used was referenced from AWS D1.1 (B-U8) CJP