MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-180 - Manual (Page 60)

Model 505.60 - 505.180 SilentFlo™ HPU 60
Precharging the Optional Surge Suppressor
Installation
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.
Checking the
precharge pressure
The nitrogen precharge should be about 50–60% of the output pressure. To check
the accumulator precharge:
1. Turn the HPU off and ensure that the hydraulic pressure is zero before
proceeding.
2. Connect the charging kit chuck valve to the valve stem on the accumulator,
or to the remote charge valve on the reservoir top, if supplied.
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), perform the procedure “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
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)