An apparatus for selecting a flow rate of a fluid includes an axle including an elongated cylindrical member having flow paths, each flow path being defined by a corresponding set of radial holes, each set of radial holes comprising at least one radial hole that extends substantially between an outer surface of the axle and an interior cavity of the axle, and a barrel including an elongated cylindrical member within which the axle is disposed, the barrel having input ports and an output port, the barrel being configured to enable the axle to rotate about an axis of rotation that extends along a length of the axle, wherein a flow rate of a fluid is selected by rotating the axle to a position so that a set of radial holes is in alignment with one or more ports of the barrel.