Grey Tank Confusion

[roach711]

Here's our grey tank. It's a 15 gallon plastic barrel and the vent is some 1/4" tubing that actually attaches to the top of the drain pipe. Works fine for us and no smell.

[FuzzWantsABus]

Why does the vent have to go all the way to the roof? Can you have a 90 degree bend in the vent? Why can't the vent just stop underneath the bus?

My understanding is that the height you can fill your tank to is limited by the height of where your waste intake is. Yes, you could put it in the side, but then you're losing the top 1-4" of fill-height inside your tank. I'm sure if I'm not correct, someone here will chime in and tell you so.

[roach711]

Running a vent to the roof is done to vent the smell up high where it can blow away without being sniffed by those down lower. An effective vent only needs to be higher than the top of the tank. Bends in the vent line are fine, you're just moving air.



The water in your drain system will always try to settle to a common level. If your tank inlet is below the top of the tank but the drain lines are higher than the top of the tank then the tank can be fully filled assuming proper venting.