Thanks for everyone's input. After seeing the photo of Bob's we found the same valve on our trailer and it worked great. It is hard to turn so I had to carefully turn it with assistance from a pair of pliars. The tank drained fairly quickly and we were in business. I think I will leave the two line drains closed since I will likely just winterize each year with the pink antifreeze, after bypassing and draining the hot water tank. We haven't put a filter in our drinking "fountain" yet so it isn't a factor.
Steve & Beth
07' Classic 31, 11' Dodge 3500 Cummins