MTS Series 322 Load Frames - Manual (Page 66)

Series 322 Load Unit 66 Maintenance
322 Load Unit: Maintenance Intervals
The following table lists the recommended interval for each of these procedures.
W HAT TO D O W HEN TO D O I T
Make daily inspections Before the start of each day’s
testing.
Clean the load unit columns When the columns become greasy
or dirty.
Prevent rust Depends on the operating
environment; more often in humid
environments.
Bleed the hydraulic lift cylinders When the crosshead begins to
move roughly; if the sealed side of
the hydraulic supply is opened to
air.
Adjust the hydraulic locks When the crosshead sticks or
moves jerkily on the column.
Lubricate the Crosshead
Locking Bolts Whenever they begin to be hard to
tighten or sticky when loosened.
Lubricate the crosshead locking
bolts When the bolts begin to loosen or
tighten stiffly (manual locking
crossheads only).
Align the force transducer After actuator or force transducer
installation; when a better
alignment between the two is
desired.
Check the accumulators’
precharge pressures. Adjust if
necessary At least once a month; more often
as required by operating
conditions.
Clean exposed actuator piston
rod Weekly; more often as required by
operating conditions.
Change 298 HSM filter. When indicator is in bypass
position or when hydraulic fluid is
changed.
Perform 252 Servovalve
maintenance: change filter. When servovalve performance has
deteriorated.
Perform 252 Servovalve
maintenance: adjust mechanical
null. After the valve balancing
procedure (electrical
compensation) has been completed
and the results are judged
unsatisfactory.