MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-11 - Manual (Page 72)

Model 505.07/.11 SilentFlo™ HPU 72
Precharging the Surge Suppressor Accumulator
Accessories
4. Open the bleed valve on the accumulator charging kit and remove the chuck
valve from the accumulator. Replace the valve stem cap and protective
cover on the accumulator.
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:
1. Slowly open the bleed valve on the charging kit until gas begins to escape.
When the pressure reading on the appropriate pressure gage drops to the
level required, close the bleed valve.
2. Close the locknut. Open the bleed valve on the accumulator charging kit and
remove the chuck valve from the accumulator.
3. Install the valve stem cap and protective cover.
Increasing pressure
To increase the precharge pressure:
1. Close the locknut on the surge suppressor.
2. Open the bleed valve two turns.
Low Pressure
High Pressure Gage
0–21 MPa (0–3000 psi)
Gage Protector
(factory set to
limit pressure to
Extension
Bleed
Input
Nitrogen Supply
Regulator
Nitrogen
Core-Type Valve
To Open and
Nitrog
Nitrogen Regulator
Regulator
You must supply these
Check
Lockn Valve
Ope Clos
Poppet-Type Valve
To Open and Close
Clos
Valve
Valve
Ope
Ope Clos