MTS Series 252 Servovalves - Manual (Page 29)

Five-Port Operation—252.2x Servovalve
Series 252 Servovalve Product Information Installation 29
Five-Port Operation—252.2x Servovalve
The Model 252.2x Servovalve can easily be changed from four to five ports. The
servovalve can be configured for pilot stage oil supply through the internal
pressure “P” port, or from a separate supply line through the “X” port. Standard
configuration is internal pilot operation with a screw and seal washer in the “X”
port. This same screw and seal washer must be relocated to the “P” port if an
external pilot oil supply source is desired. The following figure shows the screw
and seal washer locations.
Make sure the screw and seal washer are correctly relocated to the P port.
If the screw and seal washer are not correctly relocated to the P port,
pressurized oil from the PP port can make its way to the valve's P port,
which could result in pressurized oil being connected to an actuator even if
the main hydraulic supply is blocked.
This could result in dangerous actuator motion.
Important Some local regulations might require precise hydraulic labeling on
components. Upon valve installation, the nameplate must display
the proper hydraulic schematic and typecode (if applicable). When
a valve is configured for a pilot supply, please attach a lower half
label (available from MTS) showing the external (5th port)
information. An example follows.
Relocate screw and
seal washer to P
port for external (5th
port) pilot oil supply
Location of screw
and seal washer
for standard
internal (4th port)
pilot oil supply
WARNING