Was told by some very knowledgeable people that this valve does not work as well as a P trap and was advised against installing it. I had 3 to put under kitchen sink, and two bathroom sinks. After talking to these people, I decided not to put any into the coach. After that decision, a friend told me he took his Hepo out because of the odors that leaked back into the coach. If you have odors, make sure the vent lines are open, many times they become clogged with nests or other items.
Roy Warren