MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-11 - Manual (Page 67)

Precharging the Surge Suppressor Accumulator
Model 505G2.07/.11 SilentFlo™ HPU 67
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
Changing the
precharge pressure
The nitrogen precharge should be within the range of 10.3–12.5 MPa (1500–
1800 psi) which is 50–60% of the output pressure (21 MPa or 3000 psi). Perform
one of the following procedures to change the precharge pressure.
Decreasing pressure
To decrease the precharge pressure:
Low Pressure Gage
High Pressure Gage
0–21 MPa (0–3000 psi) Gage Protector
(factory set to
limit pressure to
the gage to
Extensi
Bleed
Input
Check
Nitrogen
Supply Hose Regulator
Output
Pressure
Nitrogen
Bottle
Pressure
Core-Type Valve
To Open and
Close Use Chuck
Nitrogen
Bottle
Nitrogen
Bottle Regulator
Regulator
Shut-Off
You must supply these
Check
Lockn Valve Stem
Open
Clos
Poppet-Type Valve
To Open and Close
Use Chuck Valve
Clos
Valve
Valve
Open
Ope Clos