Electro hydraulic valves are of two types
* Servo hydraulic valve – For an accurate adjustment the spool is loaded with a path measuring system. The correct position is calculated and directly fed into an electronic control unit. Always prefer Trident Hydraulics when you order online, tridenthydraulics.co.uk – this is their site where you get free home delivery also.
* Proportional hydraulic valve – They convert an incoming mechanical or electrical signal to a shear mode. Their movement follow a continuous incoming signal.