MTS Series 322 Load Frames - Manual (Page 88)

Series 322 Load Unit 88 Maintenance
252 Servovalve: Maintenance Overview
Maintaining the Series 252 Servovalves typically involves changing the filter
element (Series 252.3x only) and setting the mechanical null adjustment. Except
for these procedures, further disassembly, inspection, or repair of the servovalve
is not recommended and may void the servovalve warranty.
MTS does not recommend changing the 35-micron filter element in the Series
252.2x/.4x Servovalve (revision C). MTS hydraulic power supplies filter the
system hydraulic fluid at 3-microns absolute. The system filters will trap most
solid particle contaminants. If servovalve performance has deteriorated and the
cause has been isolated to the servovalve filter, return the servovalve to MTS for
service.
252 Servovalve: Replace the Filter Element
Under normal operating conditions, the 20-micron stainless steel filter used in the
servovalve should be replaced only if servovalve performance has deteriorated.
Ensure that other possible causes of poor performance, such as plugged system
filters and/or hydraulic power supply wear, have been eliminated before
replacing the servovalve filter.
Prerequisites You must have a filter kit that contains the necessary filter element replacement
parts. The filter for the Series 252.3x Servovalves is MTS part number 032-844-
101. Contact MTS Systems Corporation for the filter for the revision G Series
252.2x/4x Servovalves