Possible Faults Sources:
a. The delivery hose is somewhat expansive. If the hose is relatively long, the hose may be instantaneously swollen at startup, and trace of liquid oil may enters into the hose and lead to counting
b. Oil leak occurs in the bottom valve or pipeline. The oil level inside pipeline may gradually drop during the interval time between two consecutive fueling operations, such that some gases may enter into the flow meter during a next fueling operation, which may drive the flow meter to rotate for counting. The longer the interval time is, the higher the fueling volume may be excessively counted when the fuel dispenser is turned on the next time, and gas expelling may take place when the nozzle is turned on
c. Oil pipeline is laid with bow shaped sections.
a. Replace the delivery hose
c. Maintain the pipeline