Kitchen sink air gap question

[sphinx105]

We purchased an older house and are in the process of remodeling the kitchen. Both sink bowls empty into the same trap which is attached to a 1 ½” drain pipe coming up from the crawl space. The trap is connected to the drain with a tee. In the top of the tee there is an air gap just like the ones used for a dishwasher. We do not have a dishwasher or a disposal. I was planning on replacing the trap and lines connecting to the pipe going under the house while replacing the sink and was wondering what the air was for and if I could remove it? It is located well below the water line in sink, so, will it over flow if a full sink of water is allowed to drain out at once? The new sink is considerably deeper that the old one and would hold more water.

[jadnashua]

What it may be is an air admittance valve which is used instead of a conventional vent. It probably is needed to make the sink drain properly. My unprofessional opinion.

[sphinx105]

Sounds like that may be it. I don't remember seeing a vent stack on that side of the house. This house may very well be over 80 years old, last least parts of it are anyway and I guess the plumbing was added as needed.