Since pumps in the JHP family move the ram forward and backward in the fastest way and provide dual pressure and flow, they control dual speed automatically. High pressure, low pressure, and safety valves are installed inside. To provide large flow with low pressure, the low pressure safety valve is designed to withstand 20kg/cm2 or 30kg/cm2. When the pressure reaches this level, the pump is automatically switched to the high pressure mode and the pressure goes up to 700~1,500kg/cm2.