As far as positioning of the valve, hydraulic valves already exist in various ways of actuation. For example, you take a big DO8 valve which is a very large spool it’s an industrial valve. You would not make a DO8 with a lever because of what’s called flow forces.
The pressure that is acting on the spool itself is enough that it would be hard. It’s almost like a cylinder, the spool has surface area that literally would prevent someone from using a lever valve to actuate that spool because of how much force there is. You need more force, so you have hydraulic pilots but you can also have pneumatic pilots. What that means is that the actuators on either side of the cylinder and they’re like little pneumatic cylinders attached to your hydraulic valve that can then move that spool.
Even if your little pneumatic pilots, they’re only putting 100 pounds of force to that spool, that’s a lot more than you want to be putting and cycling with your arm on a lever valve.
Absolutely, you can get pneumatic pilots that can control hydraulic valves and they’re actually, I wouldn’t call them common but almost every manufacturer that makes a big hydraulic valve makes it with pneumatic operation.
The advantages of that is, that force. A lot of people have available pneumatic actuation somewhere. You can use, tiny and tiny little pilot valve that are pneumatics that can control this very large hydraulic valve.