Natural Gas line residential Code question?

Sometimes I forget we have a great resource here,

So, I'm doing a kitchen remodel on a 50yr old house.  I'm relocating a gas line for the stove and did a pre-work pressure test.  Found that I lost 2.5 psi in 15 minutes so started looking for leaks.  Found 6 so far, some easy (new cock valves) others, well it'll be some work. At working pressure I have never seen any leaks but 15 psi is test pressure.

I know (I think) that I can't use a union under or in the house, no problem, but I did find a union in the garage.  From the meter my gas line enters the garage travels about 20 ft along the wall then makes a couple 90s and goes thru the wall and under the house.  One of the leaks is at the union, not the union mating surface but where one end screws onto the pipe.

Easiest fix would be to take it apart clean it up and put it back together,

Is it OK to have a union in a gas line in the garage, I'm thinking not but what do I know?

Do left/right couplings meet code or are they  no-no?

It is not per code to have a union in the garage. It would have to be located outside. A left/right nipple and coupling would be the correct fitting to use inside a building.

No Show, Thanks for the answer,  Today I did get all 6 leaks fixed, pressure tested at 15 PSI and held it for 30 minutes with 0 loss.

Unfortunately I did it by just taking apart the sections as needed including the one with the union and cleaned and doped and reassembled with the union.  Tomorrow I'll replace the union with the left/right kit. And do the planned relocation.

Gotta Love NCKA.