Twin hoses for Black Tank Flush?

[IronCobra]

While trying to address a Freshwater tank issue, I found what appears to be two hoses for the black tank Flush system. To be clear, we have a Chaparral 360IBL Fifth Wheel with only ONE black tank. It appears that the hose connected to the Black Tank Flush inlet runs to the top of the toilet first and then another hose runs down to the Black Tank. Can anyone confirm this? Perhaps because there is plumbing between the toilet and black tank where stuff could get clogged? Anyone else have this setup?

[bubbles]

Black tank flush out plumbing should be similar to this (self contained).

[IronCobra]

Originally Posted by bubbles

Black tank flush out plumbing should be similar to this (self contained).

Ok, so ther might be a check valve/vent that goes up and then the water line coming back down. I'm guessing to prevent suction Backflow.