Is there a glossary of plumbing terms and definitions somewhere, either on this site or elsewhere? I have the NC plumbing code book but I can't find some of the terms I'm looking for. Specifically, what's a "hill inlet elbow" (maybe I'm misspelling or misunderstanding the term), and a "flat dry vent"?

Hi Frank:

Any chance you mean a HEEL inlet elbow? Here, is an elbow fitting with a hub fitting on the rear to attach a sink drain or a tub drain... see pictures. They are avialable in cast iron, ABS, and PVC. They are not commonly used today as there are usually better ways to install drains/vents. These were important back when installing cast iron pipes and lead was popular... cut down on fittings/lead work.

A "flat dry vent" doesn't (shouldn't) exist in plumbing. Here, all vents must pitch back toward the drains so water from rain/snow that gets into the roof vent can flow back to drains by gravity.

Let me know more here... see what we can come up with... ;)

MARK