I am just throwing this out there as it is my current -- untested -- plan: I am going to use 3/4" Tri-clamp ball valves actuated by a $16 12vdc windshield wiper motor.
With position feedback provided by a simple potentiometer. Net cost is like ~$20 + cost of valve, compared to $100's + valve with an off the shelf actuator.
Secondaries: Lakefront India Brown Ale
On Tap 1: Rootbeer, On Tap 2: NB White ouse Honey Ale, On Tap 3: Nitrogen, On Tap 4: Air, On Tap 5: Air
On Deck: DIPA, Imp Stout, Porter, Wheat, Black IPA
"No sense having empty carboys around when full ones take up just as much space. " - Me