sgtpickles
Mechanical
Hi Guys
I am curious if there is anything additional to note when following the ASME Section VIII Div. 1 and/or 2 rules for threaded openings. I have a high pressure vessel that I am designing (4000 psi and 400F) and wish to use threaded connections in the shell, c/w a seal weld. UG-36(3)(b) and UG-43(e) state that threaded connections can be used if they are less than NPS 2” and meet the minimum thread engagement of Table UG-43. Div. 2 part 4.5.3.1(c) also says the same thing referring to Table 4.5.1.
The vessel is made from 4.5” SA-479 round bad and has a wall thickness of 1.125”. I modeled the largest hole, ½” NPT, and performed a linear elastic FEA analysis. At these conditions, there is slight yielding on the inner surface of the nozzle which concerns me. I am even more concerned about a future vessel at 4700 psi which would have more yielding. However, the Section VIII code seems to be telling me not to worry about it. I know Div. 1 scope is technically up to 3000 psi, but Div. 2 still should apply. Thoughts?
I am curious if there is anything additional to note when following the ASME Section VIII Div. 1 and/or 2 rules for threaded openings. I have a high pressure vessel that I am designing (4000 psi and 400F) and wish to use threaded connections in the shell, c/w a seal weld. UG-36(3)(b) and UG-43(e) state that threaded connections can be used if they are less than NPS 2” and meet the minimum thread engagement of Table UG-43. Div. 2 part 4.5.3.1(c) also says the same thing referring to Table 4.5.1.
The vessel is made from 4.5” SA-479 round bad and has a wall thickness of 1.125”. I modeled the largest hole, ½” NPT, and performed a linear elastic FEA analysis. At these conditions, there is slight yielding on the inner surface of the nozzle which concerns me. I am even more concerned about a future vessel at 4700 psi which would have more yielding. However, the Section VIII code seems to be telling me not to worry about it. I know Div. 1 scope is technically up to 3000 psi, but Div. 2 still should apply. Thoughts?