The operating principle of a liquefied petroleum gas (LPG) dispensing pump is based on the centrifugal sliding motion of its vanes, and its flow rate is related to the rotational speed of the shaft. As the rotor rotates, the volume of the suction chamber gradually increases, creating a vacuum that draws in the fluid. The rotor’s rotation to a certain angle causes the volume of the chamber to gradually decrease, thereby reducing the oil pressure. To ensure the pump operates normally under rated conditions, an oil seal is installed between the suction chamber and the pressure chamber, ensuring a tight seal between the stator surface and the pump’s inner surface.