Abstract: An apparatus to control the flow rate of water between two pressurized areas, particularly for metered delivery of water to the packing of a pump's stuffing box. The object of the invention is to increase the useful life of the shaft of a process pump or centrifugal pump or any pump that maintains a stuffing box with standard packing material. The shaft is maintained by providing a steady drip-flow of water to the packing of a stuffing box, which helps to keep the packing moist and elastic, rather than brittle. Optimal moisture content of the packing lubricates the pump shaft, keeps the shaft at the proper temperature, and maintains the packing for a proper shaft seal, so as to prevent moisture from entering the gear box, or other locations that will cause permanent damage to the pump machinery. The water flow is controlled principally by a pressure-sensitive adjustment screw, having a soft-touch adjustment rubber gasket at its end.