I cant seem to get more than one pic to load, so im gonna post 3 times. Sorry in advance. A valve doesnt need a vent but a reg does. Heres a pic of the cap for the adjustment on your reg. this is the inside of the cap...and you can see the vent hole just barely in the center. The second pic will show the hole on the side of the cap where it vents to the outside. The third will show the first valve I posted with the black vent cover. This valve has the vent cap removed. These 2 valves comprise pretty much all the valves on waterheaters and furnaces made for rvs.
Crockett, Thanks that is correct only regulators have vents and not appliance valves...
Rockwood #8289 WS 2012
F250 6.0 / Husky 16k
With 4 point leveling system