The high pressure common rail limit valve produced by YS includes Bosch type and Denso type. The YS pressure limiting valve regulates and controls the oil pressure of the main oil passage. In order to ensure the normal operation of the engine, the oil pressure of the main oil passage must be appropriate. At this time, the pressure limiting valve will automatically open, and the oil will be returned through the oil pump, which can control The oil pressure of the main oil passage.