Repair previous error

[solson440]

Our laundry room has a utility sink that a previous owner installed. We had been fighting slow draining from this sink forever, until I realized that the previous owner had drained this sink into the vent. I have yet to fix it, but I'm asking for help in the proper setup

There is a main stack within a short run from where the vent pipe is. It's PVC (8", I think), and I planned to wye into that. I also want to plumb a stack for the washer drain.. I see references to a mini vent; will I need this to properly make this work? What is the best way to add the wye to the main stack? Are rubber/banded connections acceptable?

Thank you for your help.

 

[frodo]

a picture please,,or drawing, something, we are a visual bunch of plumbers

 

[solson440]

Sorry so long to reply. First picture is of the sink and where it's piped into the vent. Second picture is of the main stack approximately 7 feet from the sink.

Thank you.