MTS 318 Load Unit - Manual (Page 97)

Routine Maintenance Overview Checklist
318 Load Unit Maintenance 97
Mixing gases can produce unpredictable results.
Do not use another gas to precharge an accumulator. Use only dry nitrogen gas to
precharge accumulators.
3. Connect the nitrogen supply hose from the supply bottle pressure regulator
output to the input check valve on the charging kit.
4. Open the nitrogen bottle valve. Check the nitrogen bottle pressure gage on
the regulator. (The bottle must contain sufficient pressure to provide an
adequate gas volume.)
5. Monitor the regulator output pressure gage and adjust the regulator output
pressure valve to the required level.
Rapid flow rates with pressure differentials of more than 2.1 MPa (300 psi)
across the input check valve can damage the valve seal(s).
Avoid rapid and extreme pressure transitions.
Do not allow rapid flow rates. Open the regulator shut-off valve only far enough to
permit a gradual transfer of gas.
6. Slowly open the regulator shut-off valve until gas is heard escaping from the
accumulator charging kit bleed valve. Allow gas to slowly escape for
approximately ten seconds, then close the bleed valve. Immediately close
the regulator shut-off valve before the pressure reading on either the high or
low charging kit pressure gage exceeds the pressure level of the
accumulator.
7. Open the locknut (or open the chuck valve for a core-type valve). Slowly
open the regulator shut-off valve until the pressure indicator on either the
high or low charging kit pressure gage begins to rise. When the pressure is at
the required pressure level (recorded on the accumulator), close the
regulator shut-off valve.
8. Close the locknut (or close the chuck valve for a core type valve).
9. Open the bleed valve on the accumulator charging kit and remove the chuck
valve from the accumulator.
10. Install the valve stem cap and protective cover. Close the valve on the
nitrogen bottle.
WARNING
CAUTION