I need to put a short connector piece for a cooktop to black gas pipe that will be enclosed in a stud wall. If given the choice of any connectors, I would use a threaded coupling and a 90 degree elbow. However, I haven�t been able to determine what is acceptable code practice.

I have been studying up on the gas codes that apply to me, the IPC and UMC, and have not yet gotten an appropriate clarification for what type of connectors I can use.

L/R nipple
Ground-Joint union
Welded black pipe
Other?

thanks for the advice,

--ben