Is this vent correct upside down?
I hired a plumber to redo the old galvanized pipes and fix this leaking kitchen drain. The 2" vertical is the kitchen sink drain and also a wet vent for a basement sink, granted the new washer box next to the basement sink has a cheater valve vent also that can serve the basement sink. Plumber says all vents shroud be upside down. But in this case couldn't kitchen sink gunk get stuck here and eventually clog this vent?