Currently my kitchen Plumbing is torn apart. I had new countertops installed and the plumber came today and said the top gas cap ((?) protecter from fumes I'm assuming) no longer fit and CUT it off. He left to get new parts, never to return... So, I'm installing my faucet and replacing the PVC starting just under the Y that attaches to a P-Trap. I've been told by a licensed plumber that the P-Trap is "old school" and the dishwasher drain line can go directly into the disposal. I see where it could be attached, is this correct? I'm a "Shemale" Landlord, I've got a little experience with plumbing but far from a professional!! Appreciate any advise!
Yes. The disposal unit should have a barbed inlet that is intended to receive the dishwasher's drain line.
As others have mentioned, be sure to check that the knock-out plug has been removed from inside the barbed inlet. You can remove it by using a screw driver and a hammer.
Also be sure that you run the dishwasher drain hose up to the underside of the counter, securing it there with a clip and back down to the disposal connection. The hose is secured with a pinch or gear clamp.
Both the dishwasher and disposal unit's instruction manuals should show how to do this.
If you don't have the loop, you will most likely get a foul smell. Mine still smells with the high hose. I would think a goose need would help as it uses water as a barrier from the sewer(disposal) to the appliance.