MTS Series 252 Servovalves - Manual (Page 33)

Replace the Servovalve Filter Element
Series 252 Servovalve Product Information Maintenance 33
Maintenance
Maintaining the Series 252 Servovalves typically involves changing the filter
element (Model 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 Models
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.
Contents Replace the Servovalve Filter Element 33
Adjust the Mechanical Null 35
Troubleshooting Guide 39
Replace the Servovalve 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 or hydraulic power unit 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 Model 252.3x Servovalves is MTS part number 032-844-
101. The filter for the revision G Model 252.2x/4x servovalves is MTS part
number 100-098-436. MTS does not recommend field replacement of filters in
earlier revision servovalves.
Procedure
To replace the filter element, perform the following procedure. Care should be
exercised to prevent dirt or other contaminants from entering the servovalve
body, filter passages, or manifold/actuator ports. Refer to the following figure
during the procedure.