MTS Systems SilentFlo 505G2 Series, Manual

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Accessories
Series 505G2 SilentFlo™ Hydraulic Power Unit 75
Precharging the Surge Suppressor Accumulator
It is normal for a small amount of surge suppressor precharge loss to occur during operation. Because
of this gradual reduction in precharge pressure, the pressure should be checked and recharged (if
necessary) at regular intervals.
Determining a pressure check interval
The precharge pressure checking intervals of your surge suppressor depends on how your system is
used. Vigorous use causes more rapid pressure loss and thus requires checking and recharging more
often.
Initially, check the surge suppressor precharge pressure every month or 160 operating hours. If the
precharge pressure changes more than 200 psi during this time period, recharge the surge suppressor
and check the pressure twice as often in the future. If the precharge pressure changes less than 200
psi, check the pressure half as often.
When you have established a regular interval for checking the precharge pressure, note the amount of
pressure loss that occurs each time the pressure is checked. An increase in pressure loss during the
period between checks may indicate that the surge suppressor seals or bladder require replacement.
Checking precharge pressure
The nitrogen precharge should be about 50–60% of the output pressure. Monitor the pressure gage. If
the pressure reading is outside the range of 10.3–12.5 MPa (1500–1800 psi), perform the procedure
“Changing the precharge pressure.”
Charging Kit