There is a CPVC Reducer Elbow made available by us that is designed to fit into the exact same holes and locations where existing copper pipe is being replaced, so it has a smaller outside diameter (OD) than typical white, Schedule 40 plumbing-grade PVC. It is a kind of pipe which applied when both the elbow and closures are different in size. CPVC Reducer Elbow is often used so that different sizes of the pipes could be easily distinguished in order to make noteworthy turns.