The Servovalve may be mounted in any position provided the servovalve pressure, piston, and return ports match the respective manifold ports. The servovalve should be mounted with 5/16-18 x 3 inch long socket head cap screws. Apply a light film of oil to screw threads and torque to 120 in lbs.
It is occasionally required to adjust the flow null of a Servovalve independent of other system parameters. The “mechanical null adjustment” on Electro-hydraulic Servovalves usually allows a minimum of 20% adjustment of flow null.
The “mechanical null adjustor” is an eccentric bushing retainer pin (null pin), located above the return port designation (R) on the valve body which, when rotated, provides control of the bushing position. Mechanical feedback elements position the spool relative to the valve body for a given input signal. Therefore, a movement of the bushing relative to the body changes the flow null.
NOTE: Clock wise rotation of null adjustor pin increases flow from port No. 2. You must disconnect the servovalve from its electrical source BEFORE you adjust the null.
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