As in "Whoobitator valve" or any part of various flanges. A made up mechanical part that mechanics reference when they know you don't have a clue and they are trying to see how much they can charge you for a part that doesn't even exist.
Oh I see the problem here! That Whoobitator coupling has some loose flanges. Oh yeah, your going to have to replace the whole thing. I had a refurbed one but I just installed it in a rig like yours last week.