I asked some follow-up questions. Additional information:
-Two people did inspect it prior to calling me. One of the two is a DOT inspector.
-They expressed that this is the first spun steel tank with a thread crack that they’ve handled.
It just keeps getting worse! There is no such thing as a spun steel tank.
The manufacturing processes are either deep drawing and then rounding the neck and shoulder, or rounding the top and bottom of a steel cylinder and welding up the rounded bottom.
Michael