Help! It has been 3 weeks, 3 trips from 3 different plumbers and I still don't have the lines where I asked them to be put. Could someone tell me if there is any reason why a gas line can not be run inside a wall? I have a small laundry room with a large stackable in it. The original plumber ran the pipe up through the floor into a wallspace(the wall is taken down to the studs) where I wanted it and then ran flex... problem was he then hard piped the back of the dryer to the flex which would cancel the warranty on the new dryer etc. I had him come back to remove the hardpipe. He did but then moved all pipes to the other side of the room and cut a hole in my floor and ran pipe up behind the wall so it could no longer go against the wall and installed the shut off behind the washer. I had someone else come back and he said he would put the pipe back in the wall... He did, but then ran the pipe outside the studs and around a corner to behind the washer again and put the shut off valve in an exposed location where it could and probably will be accidentally turned with things moving in and out of that space... could someone tell me if there is some reason pipes cannot be put(about 2 feet worth)inside a non-load bearing wall with the shut off valve recessed and boxed for access?

Correction... 2 different plumbers.