i also got the waste tank finished up today.
i still needed the vent line in before i could put the wall panels back up.
1/2" pex vent line was the easiest project i've done on the bus in a long time.
the tank is on the wrong side of the bus..... so it starts there, and runs between the frame and across the bottom of the bus.
then it comes up through the floor and out the wall.
and the vent fitting on the outside, driver side.
all one pipe, no fittings except the 2 ends