Ok... here is the situation:

In the utility room, on the left wall I have the washer and a utility sink with a vent in that wall (vent goes up and then through the roof).

I want to move the washer and utility sink to the right wall, but need to have a vent for the sink and washer drain. My question is as follows:

Can I vent the new drains above the sink flood line (for example, at 42"), then go down about 60" through the floor into the basement, then across to the other side and connect to the vent in it's current location ?

I know that usually vents up, but I don't see what can be the problem in the configuration I described above.

Any feedback wil be helpful... thanks.