MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-180 - Manual (Page 44)

Description Name and Location
shows factory settings that should not be changed by
the user.
About the Optional Surge Suppressor
Accumulator Precharge
The surge suppressor, if provided, smooths out the ripple caused by the pulsing action of the pump as it
pressurizes the hydraulic fluid. The surge suppressor is a cylinder that has an outer sleeve that is pressurized
with nitrogen. The gas pressurized sleeve dampens the pressure pulses.
The surge suppressor is mounted to the output of the hydraulic pump inside the reservoir.
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.
Determine 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 1.4 MPa (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 1.4 MPa (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 might indicate that the surge suppressor seals or bladder require replacement.
Check the Precharge Pressure
1. Monitor the pressure gage.
2. If the pressure reading is outside the proper range, increase or decrease the pressure as appropriate (see
).
• The nitrogen precharge should be within the range of 50–60% of the output pressure.
• For an output pressure of 5 (21 MPa or 3000 psi), the correct precharge pressure is 10.3–12.5 MPa
(1500–1800 psi).
44 Series 505G2 SilentFlo™ Hydraulic Power Unit Product Information
Installation