Hi everyone, wondering if anyone had any insight here. I just had some gas line installed by a plumber. When he finished he put air into the line (25PSI). A day later the pressure has dropped to (11PSI). He mentioned it should be anything to worry about because air changed and expands based on temp and he also mentioned that his valve maybe leaking. So my question is does that make much sense? If the PSI is dropping doesn't that mean there is a leak in the system and when gas gets connected isn't it going to leak out as well?

I think the local inspector uses 5PSI for 24hrs for final inspection.