I was just going to ask a question 😂 about different welding test for a job. I am a shop welder and have had some really different style of test. Some were just let me see you run some beads and others were very formal plate test. Some will give you a lot of info about the test and some will not. One job said an open root test and it was not an open root test.

Good headshots

I wonder 🤔 why it cracked at the toes? Maybe not hot enough when welding. I googled 515 grade steel for reference learned something new. Course grain steel intended for intermediate / high temperature service in boilers and other PVQ applications. This grade is produced in both the As Rolled and Normalized condition.

That's big 🤯

Did some more research apparently most copper nickel alloy pipes have at least a 50% or more copper content. Copper does not make sparks when grinding. I saw an iso marking on the pipe. I do not know what it means.?

I usually do the root with MIG the the fill and cover pass are with dual shield JD Brewer