This pic is very similar to my setup in my laundry. My vent stack drain is off to the right side of the wall. If i wanted to put the sink to the left of the washing machine and about 18' away from the main vent stack, what changes would be made to the pic? I am trying to fit sink, washer, dryer from left to right along the wall. The sink will start at one end which is about 18' away from the main vent stack. The pic also shows a 1 1/2" horizontal pipe along the top that runs to the vent. What is the minimum height that can be run at?