Impeller blade pitch control is used in propeller pumps with axial and mixed flow impellers to change the pitch of the impeller blades during operation. At constant rotational speed, impeller blade pitch control changes the flow rate, head, and power input of the pump, enabling optimal closed-loop control with low losses. Considerable outlay is required for this configuration, however.

On smaller propeller pumps, blade pitch is frequently adjusted manually with transmission gearing, also known as Adjustment mechanism.

The adjustment mechanism is a gear unit which allows small propeller pumps to be manually adjusted. The axial movement of the rod is translated into a rotating movement of vane trunnions and thus the vanes themselves.

The impeller blade pitch can also be adjusted by an adjustment mechanism which is fitted in the impeller hub, together with the hydraulic or electric actuator, or by adjustment mechanisms which rotate the blade trunnions via rotation of the adjusting rod. Impeller blade pitch control as applied to centrifugal pumps evolved from early designs used for ship propellers and water turbines.