MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-30 - Manual (Page 36)

Model 505.20 - 505.30 SilentFlo™ HPU 36
Precharging the Surge Suppressor Accumulator
Installation
3. With an open-end wrench, turn the locknut counterclockwise on the
accumulator valve assembly to open the valve. Read the pressure on the
high pressure gage.
• If the pressure reading is outside the range of 10.3–12.5 MPa (1500–
1800 psi), refer to the procedure on changing the precharge pressure.
• If the pressure level is within the range of 10.3–12.5 MPa (1500–1800
psi), turn the locknut clockwise to close the valve and continue this
procedure.
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.
High Pressure Gage
0–21 MPa (0–3000 psi)
Gage Protector
(factory set to limit
pressure to the gage to
approximately 1.4 MPa
(200 psi)
Extension Hose
Bleed Valve
Input Check
Valve
Nitrogen Supply Hose
Regulator Output
Pressure Gage
Nitrogen Bottle
Pressure Gage
Core-Type Valve
To Open and Close Use
Chuck Valve
Nitrogen
Bottle
Nitrogen
Bottle Valve Regulator Output
Pressure Valve
Regulator Shut-
Off Valve
You must supply these items:
Check Valve
Locknut Valve Stem
Open Close
Poppet-Type Valve
To Open and Close Use
Chuck Valve
Close
Valve Stem
Valve Core
Open
Open Close
Low Pressure Gage
0–2.1 MPa (0–300 psi)