The company of excavator hydraulic components will provide universal components, valves for example. But the opening throttle area cannot suitable completely for all design requirements of the excavator. To the whole machine manufacturer, even if the excavator in the same weight may require individual parameters because of the different factors, such as the working device, pump, or engine. As a result, it is necessary to have test and debug some parameters to adept the target machine. To the hydraulic components, it may have a better cooperation with the whole machine after a little change of tiny parameters. A good energy saving effect and high manipulative performance may get.