Page 12 Section 6
Rotator Maintenance
MSD SABER SERIES SHEARS
TESTING THE ACCUMULATOR
PRECHARGE
Once the test united is attached, make sure the
relief valve is closed and then turn the spindle. When
the pointer of the gauge begins to move, turn the
spindle one more full turn. The gauge should now
show the amount of accumulator precharge pres-
sure. The proper amount of accumulator precharge is
1100 - 1200 PSI (76-83 BAR). If the gauge is showing
something other than the proper precharge, it will
be necessary to either release pressure or further
precharge the accumulator.
TESTING THE ACCUMULATOR
PRECHARGE
Once the test united is attached, make sure the
relief valve is closed and then turn the spindle. When
the pointer of the gauge begins to move, turn the
spindle one more full turn. The gauge should now
show the amount of accumulator precharge pres-
sure. The proper amount of accumulator precharge is
1100 - 1200 PSI (76-83 BAR). If the gauge is showing
something other than the proper precharge, it will
be necessary to either release pressure or further
precharge the accumulator.
PRESSURE RELEASE
To release pressure, slowly open the relief valve (see
Figure 6-7
). This will release nitrogen into the atmo-
sphere. Close the valve when the desired pressure
is reached.
ACCUMULATOR PRECHARGE
Never use oxygen or shop air to precharge the
accumulator. This could cause an explosion! Use
only dry nitrogen for precharging accumulators.
1.
Connect a charging hose to the shut-off valve of a
commercially available nitrogen supply bottle. Con-
nect the other end of the charging hose to the nipple
of the charging unit. With the spindle open, slowly
open the valve on the nitrogen supply bottle to re-
lease nitrogen into the accumulator until the desired
level is reached.
2.
Allow fi ve minutes for the nitrogen temperature
to adjust. Recheck and repeat process until proper
pressure (1100 PSI/76 BAR) is reached.
3.
When the required precharge pressure is reached,
unscrew the spindle valve so the gas valve on the
accumulator closes. Check the valve on the accumu-
lator for leaks by using sealing spray or soapy water.
Replace cap nut and protective cap.
If the gas pressure in the nitrogen supply bottle
is higher than the maximum operating pres-
sure of the accumulator, a gas pressure reducing
valve or regulator must be fi tted.
FIGURE 6-7
NIPPLE
RELIEF
VALVE
SPINDLE
SCHRADER
VALVE
O-RING
CAP NUT
CAP
