Hi all, in the final phases of replacing the old pipe in my basement. I've got three (easy?) questions...

1. Frost-Proof Hose Bib - How far into basement does the stem need to reach. The hose is going through about 10 inches of brick and concrete before reaching the interior basement space. I've got a 12" long Woodford Hose Bib... should the 2 inches it extends into my basement offer enough protection or will I need to special order a longer valve so it reaches futher inside?"

2. System Drain - If I install a boiler drain near my service entrance to allow me to serve as a system drain, should I place it before or after the Pressure Reducing Valve? My PRV doesn't have a backflow preventor.

3. Flushing New Pipes - Is it necessary to flush out new pipes after they are installed to remove flux and any other crap inside? If so, anyone have any idea how long to flush them for?