The pressure adjustment cartridge valve is for Kobelco SK230 Excavator machines, we also produce the series cartridge valves for SK100, SK120, SK200-1-2-3-4-5-6, SK330, SK330-6 series excavator machines. The Pressure adjustment cartridge valve is to adjust the system presetting pressure when the output pressure of the pump is increasing or decreasing while operation, keeping the normal operation pressure.