Bob, when I installed ours the new type were not available. I cut the dump pipe just behind the nipples, cemented on a sleeve over the pipe, then cemented the new gate valve inside the sleeve. It has the fitting for the cap on the end. End result was the dump pipe is a bit longer and has a permanent gate valve just before the cap. Had the new twist on been available I'd have gone that route. Camping World has it. Probably some RV Dealers have it or can get it.
http://www.campingworld.com/browse/s...9&skunum=27868