Gas Line Union

Several months I had a backup generator installed. The plumber ran a copper pipe from the outside propane tank to inside the basement. Then he installed a union to black piping across the basement and out to the generator on the other side of the house. Now I'm planning to finish the basement and realized the union will be hidden by the finished ceiling. Since that's a no-go, what's the solution? I'll have a plumber do the work but am wondering how he will join the copper and black pipe without a union? Will he have to extend the copper to an unfinished part of the basement and reroute the black pipe?

I wish I had thought more about the basement finishing project when the generator was being installed.

Thanks.

pipe

I am wondering what kind of connection he used to join the two if he NEEDED a union. The common way would have been to use a flare adapter, and that can be concealed.

Like HJ said, there at least one connection allowing it to be concealed. Make sure it is dielectric as well!

Just have a small access panel installed in the drywall. You'd probably only need a 6"x6" or so to pass inspection/code requirements in your area.

After looking at a picture of a flare adapter I think that might be what is it, not a union. I'll take a closer look tonight. Thanks.