The ever growing use of Cartridge Hydraulic Valves is showing productivity gains in all basic areas. Manufacturing man-hours are reduced since Cartridge Valves in a manifold can form the complete hydraulic control system. These control systems will have been tested as individual Cartridge Valves and, when required, as complete systems prior to shipping to the assembly point. Assembly man-hours are greatly reduced at the final assembly plant since fewer components must be mounted and fewer piping connections made. Reliability is improved due to reduction in contamination, leak points and fewer chances for assembly mistakes.