The Gold Cup series are piston pumps. This means that as the shaft turns, it drives pistons up and down. The pistons in turn move the hydraulic fluid. Many types of pumps are available in the series, including the 013-41338-0. This pump moves 7.25 cubic inches of fluid per shaft revolution, and has a maximum output pressure of 5,000 psi. The recommended shaft turning speed is 3,000 rpm, in a clockwise direction.
A variable displacement pump's output is dependent upon shaft rpm. The faster the shaft turns, the higher the output. One such pump is the PD018PB. It has a maximum displacement of 18 cubic centimeters per revolution, and has a maximum pressure of 4,460 psi. The rotation of the shaft is clockwise. These pumps can withstand ambient temperatures of over 200 degrees Fahrenheit.
A vane pump does not use pistons, but rather uses an impeller, much like a water pump in an automobile engine. A vane pump also produces variable volume. The faster the shaft turns, the higher the output. For the 014-70298-0 pump, the maximum output is 227.1 milliliters per shaft revolution. This is about 1 cup per shaft revolution. The maximum recommended speed is 2,200 rpm, with a clockwise rotation.