Abstract: A pulseless, reversible, precision piston-array pump. The pump head has a cylindrical body which rotates inside a cylindrical casing. A cam cap closes one end of the pump body, and a port cap the other end. The cam cap has on its interior surface a groove which controls the timing and depth of the piston strokes. The port cap has on its interior surface an inlet valve groove and an outlet valve groove to provide the valving action which controls the direction of fluid flow. At all times during the operation of the pump, at least one piston is in a compression mode; At least one piston is in a suction mode; and at least one piston is in a null mode, performing neither compression nor suction while moving across the port cap. This design decouples the rotary movement of the cylindrical body from the linear movement of the pistons, to provide pulseless flow for the pump.

Abstract: A method for merging and/or ratio-blending aliquants from two different streams in a first channel, and utilizing a second channel to propel merged and blended aliquants through a separate, pumped carrier channel by providing a pump comprising a plurality of pistons, a plurality of inlet ports, a plurality of outlet ports, a cam cap having cam profiles which controls timing and depth of strokes of the pistons, and a port cap having a plurality of valve grooves which control a direction of fluid flow.