There are a number of styles of Vane Pumps available including sliding vane, external vane, flexible vane, rolling vane, and swinging vane pumps. Most operate on the same principle: there is a slotted internal rotor in which the vanes slide and an eccentric cam that changes the volume between vanes as the pump rotates. As fluid enters the pump, the vanes begin sliding out of the rotor to their fullest extension, creating a pocket of pumped media. The rotor continues to rotate, carrying the fluid from the inlet to the outlet, and as the fluid pocket approaches the outlet, the cam compresses the vanes back into the rotor forcing the fluid out of the outlet of the pump.

Vane pumps are strong performers in pumping lower viscosity fluids and are capable of self-priming. Due to their design and materials of construction, they also compensate for wear meaning that they're a good choice to pump non-lubricating fluids such as LP gas and ammonia. In addition, they're easily and inexpensively maintainable.