Install a sanitary tee in the sink’s drain line, inside the wall cavity. Use the PVC sanitary tee for a 2-inch waste line. Ensure to install it no farther than 3 1/2 feet from the bottom of the P-trap. Glue the tee to the pipe coming from the sink, using PVC cement.Click to see full answer. Also asked, does a kitchen sink drain need a vent?Every sink needs a sink vent. A plumbing fixture like a sink can not function properly without a sink vent. A sink needs a vent because the pressure put on the drain pipe when water flows down the drain pipe needs to equalize. The air needs to escape the drain pipe in order for the sink to vent.One may also ask, how do I know if my plumbing vent is clogged? The top three signs your plumbing vent is clogged include: Sputtering, gurgling toilets. When airflow is inadequate in a vent because of size or blockage, the plumbing pressure will be greater than the air in the bathroom. Slow drain. Strong sewer gas odor. Additionally, how far can a sink be from a vent? If the waste line has a diameter of 1 1/4 inches, the vent can be no farther than 2 1/2 feet from the trap. If the waste line is 1 1/2 inches, this critical distance is 3 1/2 feet. The minimum diameter of the vent pipe is 1 1/4 inches in both cases.Does the vent go before or after the P trap?Vent must be within 24″ of the p trap to be efficient. Drain must go down directly into p trap to prevent having a running trap. You do not want a running trap. Vent should be pitched up 45 degrees on run minimum.