Cartridge kits are the primary method for servicing pumps, as they restore pump performance, lower replacement costs, and minimize downtime. Cartridge kits for VQ series, V series, and PVL series vane pumps are designed to service both single and double vane pumps. The cartridge kit is designed to be independent of the shaft, allowing for easy changes in flow capacity and field servicing without the need to remove the pumps from their mountings.