A vane pump works by compressing volume to increase pressure and create vacuum. Vane pumps can handle low-to-medium viscosity fluids such as propane, gasoline, fuel oils, solvents, ammonia and refrigerants. They have no metal-to-metal contact, which allows them to operate at peak performance with non-lubricating liquids.

Vane pumps are available in a variety of configurations, including a sliding vane pump, flexible vane, rolling vane, swinging vane and external vane. Vane pumps are known for their dry priming, good suction and easy maintenance. Each type of pump is needed for certain jobs: For instance an external vane pump can handle large solids, whereas a flexible vane can only handle small solids.

According to Pump School, a slotted rotor is fitted onto a cycloidal cam. The rotor is located close to the wall of the cam and creates a crescent shaped cavity. Two side plates seal the cam in on both sides. Blades are fitted to the impeller and as the rotor is turned, fluid enters the pump. The centrifugal force, hydraulic pressure and push rods then push the blades closer to the wall of the housing. The cam and housing push fluids into the pumping chamber via holes in the cam. As the rotor spins, the blades move the fluid to the opposite side where it is squeezed through the discharge holes in the cam, exiting through the discharge hole.