So I wonder what I need.
I only need 90 degree movement, but I prefer an adjustable type like my CVA 24. I set the solar roof heater to "leak" a little to help it drain quicker when it shut off so I didn't have to listen to "gurgle gurlge gurlge" for an hour. It has a vacuum breaker on the roof part of the system, but it's not working very well, if at all.
Attached are the positions I need - Note that the one with the handle is not at 90 degrees. In practice I'm only off a couple of degrees. That is the position I don't close 100% for drain down.
Thanks in advance...