Vickers KDG and KTG valves are non-feedback type proportional valves.
The KDG is a proportional directional valve with two solenoids (C models). It incorporates control of flow, direction, acceleration, and deceleration in a single control valve.
The KTG is a proportional throttle valve with a single solenoid. B models are spring centered with solenoid A removed. F models are spring offset to port A and respond to an increasing signal by reducing the flow rate. The KTG’s spool can be infinitely positioned to achieve throttling (restriction) of the fluid flow.
The primary function of these valves is to direct and meter fluid flow in proportion to current received by the solenoid. This fluid flow controls the velocity, direction, and acceleration or deceleration of a work cylinder or fluid motor.
These valves are designed to fill the performance gap between conventional solenoid operated directional valves and servo valves or feedback-type proportional valves. They provide control of spool position and metered fluid flow in applications that don’t require the high levels of accuracy, repeatability, or response possible with feedback-type proportional valves or servos.
Used with Vickers electronic amplifiers, these valves provide an interface between control system intelligence and hydraulic muscle. This is a very practical way to control actuator direction and speed while eliminating shock caused by rapid acceleration and deceleration of machine loads.
In addition to improving machine performance and life, these proportional valves substantially simplify system design by combining direction and flow control capabilities in one package that mounts to a standard NFPA/ISO subplate or manifold interface.
The valve can also be readily tailored to a vast array of applications by specifying the specific valve configuration which best meets system requirements.
The valve is controlled by applying current to either solenoid A or solenoid B. This current produces a force at the solenoid push pin which, in turn, causes spool travel. The spool will continue its motion until the solenoid force is balanced by the return spring force. Therefore, spool travel is proportional to the amount of current passing through the solenoid coil