Had an idea for a further improvement if possible...in addition to being able to read the contents of the segment, is it possible to add an Enable function to the valves? (Or a 4th circuit controllable valve.) I'm looking to be able to control flow through the valve by circuit without using a pump.

I'd like to, but it's not possible without a lot more run-time scripting, as far as I know.
The valves are modified storage tanks, which is why you can read their contents with wires. To add a wire-controlled valve would just add another kind of pump with the same limitations (no reverse flow possible, always tries to flow at its max speed). The additional function is not worth the complexity of developing and maintaining it, and the performance cost to players.

Fair enough. Adding a pump generally isn't a problem, but it seemed like overkill if all I wanted to do was stop or start a flow and didn't need the pump aspect so I thought I'd put the idea out there. If it isn't going to work efficiently, then you are right, it isn't really worth the effort. Thanks