Originally Posted by perryg114
Do you need to drain the tank in order to put in one of these valves?
Most tanks already have a "wet leg" with a fitting on top of the tank for it. The fitting is brass and has a Schrader-type valve in it (like a tire valve only larger) with a brass plug attached. It is possible to remove the plug with minimal propane leakage since the Schrader valve remains closed until a liquid dispensing valve is installed in place of the cap.
I have a wet leg setup with no pump for filling tanks but have come to find it to be enough of a nuisance to use that I usually get the tanks filled at a propane dealer. The propane places around here have reasonable prices. I've also found that U-haul usually has good prices. Campgrounds and truck stops charge the most.