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A
747-400
MAINTENANCE MANUAL

CHARGE FITTING

N2 STORAGE CYLINDER/ RESERVIOR SCALES CO2 STORAGE CLYINDER
ASSEMBLY
Charging Set-Up
Figure 205

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K17186
A
747-400 MAINTENANCE MANUAL
 S 972-044
 (16)
 Weigh the gas cylinder. Find the correct weight of the N2.

 S 612-043

 (17)
 Add or bleed the N2 to get the correct weight of 9.38 - 9.42 pounds.

 C. Charge the gas cylinder with Carbon Dioxide (CO2) as follows:
 S 612-068
 WARNING:_______HOLD THE CHARGE FITTING HOSE. USE A GUARD TO PREVENT INJURY OR DAMAGE TO THE EQUIPMENT IF THE CHARGE FITTING HOSE BECOMES UNSERVICEABLE.
 CAUTION: EXAMINE THE GAS CYLINDER TO MAKE SURE THAT THE COMPONENTS ARE
_______ IN ALL OF THE WEIGHINGS TO GIVE THE TOTAL WEIGHT OF THE GAS.
 (1)  
Connect a hose to the output side of the portable servicing unit and the inlet charge fitting on the gas cylinder. Balance the scale (Fig. 205).

 S 612-046

 (2)  
Connect the CO2 source to the input side of the portable servicing unit.

 S 612-047

 (3)  
Open the charge fitting on the gas cylinder.

 S 612-048

 (4)  
Turn on the air supply. Adjust the pressure to 145-155 psig.

 S 612-049

 (5)  
Open the valve on the CO2 storage cylinder. Adjust the pressure to 300-500 psig.

 S 972-050

 (6)  
Continue pressurization until the weight of the gas cylinder has the weight of CO2 at 3.98 - 4.02 pounds at 70 degrees F.

 (7)  
Close the air supply to the portable servicing unit.

 (8)  
Close the charge fitting on the gas cylinder.

 (9)  
Torque the nut to 120-130 inch pounds.

 (10)
 Disconnect the hose from the charge fitting.

 S 612-051
 S 612-052
 S 422-053
 S 612-054
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747-400 MAINTENANCE MANUAL
 S 612-055
 (11)
 Close the valve on the CO2 storage cylinder.

 S 972-056

 (12)
 Weigh the gas cylinder. Find the correct weight of the CO2.

 S 612-057

 (13)
 Add or bleed the CO2 to get the correct weight of 3.98 - 4.02 pounds.

 S 972-058

 (14)
 The total weight of the gas cylinder with N2 and CO2 will be 13.38 -

13.42 pounds at 70 degrees F.
 S 612-063
 (15)
 Four hours are necessary for the gas cylinder and gas to get to the same temperature.

 S 612-064

 (16)
 Add N2 or bleed gas from the gas cylinder to get a correct pressure of 3000 - 3050 psig at 70 degrees F.

 (17)
 Replace the cap on the charge fitting.

 (18)
 Weigh and record the total gas cylinder weight.

 S 422-065
 S 972-066
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