A proportional directional valve is used to regulate the flow of liquids and gases.  The valve spool can be shifted to change the direction of the flow.  There are a number of applications for proportional valves, including sewage treatment and oil distribution.  In addition, proportional valves provide the advantage of fast response and consistent control.

Proportional directional valves come in different sizes and types, allowing you to find a device that is suitable for your needs.  These devices are also available for open and closed loop operation.

Some proportional valves may have a feedback control circuit to reduce speed changes.  Onboard diagnostics are also available.  When selecting proportional valves, keep in mind that most cannot respond rapidly to sudden system changes.

Proportional valves are controlled by DC power.  They are generally programmable.  This means that you can set the speed of the servovalve spool, based on an electric signal.  It is common to use a command voltage of 0 to 10 volts.

Proportional directional valves are made of a high-quality design.  However, they have a tendency to be sensitive to environmental factors.  As a result, changing out parts that aren't needed can introduce contaminants into the system.

Proportional directional valves have two basic features: a meter-out function and an anti-cavitation check valve.  These functions enable fluid from a tank to pass into the cap end of a cylinder.  If the cylinder cap is not full, the flow cannot continue.

A proportional directional valve can be a cost-effective solution to complex circuits.  It has the ability to adjust flow volumes and pressures, and can be used at various flow rates.