Operation and maintenance manual

Section 250-0060
SM 2160 7-02
3
Braking System - Accumulator
7. Close cylinder valve (4) and open bleeder valve (10)
to dissipate gauge pressure. Close bleeder valve (10)
after pressure is relieved. If the accumulator needs
charged, leave line (1) and valve chuck (2) attached to
charging valve (1, Fig. 1)). Charge the accumulator as
described under 'Charging The Accumulator'.
8. If precharge pressure is correct, rotate 'T' handle
anticlockwise until it stops. Tighten locknut (1D, Fig. 1)
on charging valve (1, Fig. 1) to 11 Nm (100 lbf in).
Loosen the swivel nut and remove gauging head.
9. Install cap (1A, Fig. 1) on charging valve (1, Fig. 1)
and tighten finger tight.
10. Remove wheel blocks and place the battery
master switch in the 'On' position.
CHARGING THE ACCUMULATOR
Numbers in parentheses refer to Fig. 2, unless
otherwise specified.
Note: Either oil or water pumped nitrogen can be used
to charge the accumulator. Both types are readily
available from a local compressed gas dealer.
WARNINGS
Do not use Oxygen or any gas other than
Nitrogen to charge an accumulator. Oxygen
under pressure coming into contact with oil or
grease will cause a violent explosion. Always
double check to make sure you are using
Nitrogen to prevent personal injury and
property damage.
A high pressure nitrogen pressure
regulator must be used with the charging
assembly kit. Failure to use pressure regulator
could cause property damage, personal injury
or death.
1. Attach line (1) and the swivel nut to charging valve
(1, Fig. 1) as described in steps 1 through 4 under the
heading 'Testing Precharge Pressure'. Be sure valves
(4 & 6) are closed.
2. Attach gauging head to nitrogen bottle by screwing
down on gland nut (8).
3. Open tank valve (6) slowly; pressure shown on
pressure gauge (5) is tank pressure.
4. Open cylinder valve (4) slowly and charge
accumulator to 55 bar (800 lbf/in
2
) at 21° C (70° F)
ambient temperature, closing valve occasionally. Refer
to the table at the end of this section for nitrogen
pressures at ambient temperatures of other than 21° C
(70° F).
5. To check accumulator charge, close tank valve (6),
relieve pressure between tank and pressure gauge (5)
by opening bleeder valve (10) momentarily. This will
allow gauge needle to settle, thus giving correct
pressure reading of accumulator charge.
6. When the correct pressure for the ambient
temperature has been reached, close valves (4 & 6)
tightly. Bleed pressure off pressure gauge (5) by
opening bleeder valve (10). Close bleeder valve when
all pressure is bled off from the gauge and unscrew
gland nut (8) from the nitrogen bottle.
7. Rotate 'T' handle of valve chuck (2) anticlockwise
until it stops, tighten locknut (1D, Fig. 1) to 11 Nm (100
lbf in), loosen the swivel nut and remove gauging
head.
8. Check charging valve (1, Fig. 1) for leakage using
soapy water. Reinstall valve cap (1A, Fig. 1) and
tighten finger tight.
DISCHARGING NITROGEN
Numbers in parentheses refer to Fig. 1.
Make sure charging valve (1) is closed internally by
turning locknut (1D) clockwise. Remove cap (1A) and
core (1B) from charging valve (1). Slowly turn locknut
(1D) anticlockwise to open charging valve (1).
Do not remove charging valve (1) until all the gas has
been completely evacuated.
WARNING
Do not try to discharge the accumulator by
depressing charging valve core (1B).