Compac CNG Service Manual page 38

Refuelling a Vehicle
Fast Fill Refuelling Process
Compac Industries Ltd.
The fast fill refuelling process uses pressure sensors to calculate the
quantity of gas required to fill a vehicle to a configurable target fill
FPA)
pressure ( .
The technical operation of a fast fill dispenser is as follows:
1. Press the start button or remove the nozzle from the holster to
initiate a fill.
The display will show
the gas and value totals will display
2. Connect the refuelling nozzle to the vehicle
3. The refuelling valve is opened and when flow is detected the
solenoids shut immediately. Pressure reading (P1) and amount
dispensed (KG1) is recorded.
4. If the vehicle is within 20 bar of the target pressure (
filling takes place.
5. The solenoids are opened and filling continues as follows:
 If P1 was less than 50 bar, the fill will continue for 20
seconds.
 If P1 was greater than 50 bar but less than 100 bar, the fill
will continue for 14 seconds.
 If P1 was greater than 100 bar but less than 150 bar, the fill
will continue for 10 seconds.
 If P1 was greater than 150 bar but less than 180 bar, the fill
will continue for six seconds.
6. The solenoids shut and pressure reading (P2) and amount
dispensed (KG2) are recorded.
7. The amount of gas (KGf1) to completely fill the vehicle to
calculated as follows:
KGf1 = (KG2 – KG1) x (FPA – P1) / (P2 – P1).
8. The dispenser fills to KGf1 and stops. This is the end of the fill.
Page 38
Dispenser Operation
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FPA)
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FPA
is