MTS Series 252 Servovalves - Manual (Page 30)

Series 252 Servovalve Product Information 30
Five-Port Operation—252.3x Servovalve
Installation
Five-Port Operation—252.3x Servovalve
The Model 252.3x Servovalve can easily be changed from four to five ports. The
fifth port provides hydraulic pressure to the spool even when station pressure is
removed. The following procedure describes how to open the fifth port and block
a secondary port to the filter.
The five port configuration can be changed back to a four port configuration. Use
the following procedure as a guideline to remove the plug in the secondary filter
port and install it into the fifth port on the bottom of the servovalve.
1. Turn the hydraulic pressure off.
Ensure that system hydraulic pressure has been reduced to zero before
proceeding. To do this, turn off the hydraulic power unit and exercise the
actuator until it stops moving. Then, turn off electrical power to the
controller.
2. Open the fifth port.
A. On a new servovalve, remove the protective cover plate (attached to the
bottom of the servovalve).
On an existing servovalve, remove the servovalve from its mounting.
B. Use a 1/8 inch Allen driver to remove the Allen screw covering the
fifth port
.
C. Inside the port, use a threaded screw driver (#2 -56) to connect to the
inner plug.
D. Pull the threaded plug out of the fifth port.
3. Remove the filter.
E. Remove the four socket head screws and washers that secure the filter
cover plate to the filter housing.
F. Remove the filter cover plate.
G. Remove the filter plug by threading one of the socket head screws,
removed in Step E, into the filter plug and pulling it out of the filter
housing.
H. Remove the filter.
4. Close the secondary filter port.
4 Ports Fifth Port