I am planning to lower the height of my kitchen drain outlet from the wall in order to accommodate a garbage disposal but I am unsure of which sanitary tee to use. My current plan is to use a 2 x 2 x 1.5 sanitary tee that stubs up to a 1.5" trap adapter. However, I see that there is also a 2 x 2 x 2 sanitary tee available. Which sanitary tee is considered standard for a kitchen sink? Also, if the 2 x 2 x 2 sanitary tee is preferred, what fittings would I need to reduce to the 1.5" pipe from the kitchen drain?
I have seen both 2" and 1-1/2 adapters at the drywall waiting to accept the white "tubing" (yup, that what plumbers call it, the thin white pipe used under the sink). From a practical standpoint, as to what readily available at your local hardware store, I would choose the 1-1/2 ABS sanitary T plus an adapter at the wall. You can also use the 2" abs and adapt down to 1.5" abs in two abs pieces, then get an abs straight piece then the 1.5" abs to male threaded tubing adapter. The latter solution has more pieces and is therefore slightly costlier.
I'll let someone else pontificate on Code.