We needed a dog barrier for our living room to keep out doggie visitors.  Here's what we built from PVC pipe. This is about a 6 food wide opening. The piping is press fitted together.  We didn't use any glue. This is short enough that anyone can step over yet tall enough to imply a barrier.        The important part is the hook that we made that semi-locks the barrier into place.        We can take the barrier down by just twisting off this lever/catch.  They come out easy if they aren't glued.     We take the whole thing down when we have guests  or when the Mah Jongg crowd comes over.