According to similarity theorem, the cutting formula of vane pump can be derived. In the rated speed of the condition, the impeller before cutting the flow and cutting after the flow ratio is equal to the diameter of the impeller before cutting and the diameter of the impeller. Under the condition of rated speed, the head ratio of the impeller before cutting is equal to the square of the diameter ratio of the impeller before cutting. It can be cut directly according to the formula.
Impeller cutting refers to the diameter of processing impeller to reduce the flow of energy to the system. Impeller cutting for overly conservative design or system load changes caused by the pump capacity is a very large situation is a very useful improvement measures. The impeller cutting reduces the end speed of the impeller, and thus directly reduces the energy transmitted to the system fluid medium, and reduces the flow and pressure produced by the pump.