Structural principle of low pressure spill valve

Structural Principle

The spill valve has a remote control port. If the remote control port is connected to another remote pressure regulating valve through an oil pipe (the structure of the remote pressure regulating valve is the same as the pilot control part of the overflow valve), adjusting the spring force of the remote pressure regulating valve can adjust the hydraulic pressure at the upper end of the main valve core of the overflow valve, thereby achieving remote pressure regulation of the overflow pressure of the overflow valve. However, the maximum pressure that can be adjusted by the remote pressure regulating valve shall not exceed the adjustment pressure of the pilot valve of the overflow valve itself. When the remote control port is connected to the oil tank through a two position two way valve, the pressure at the upper end of the main valve core approaches zero, and the main valve core moves up to the highest position. The valve port is opened very large. Due to the soft spring of the main valve, the pressure at the outlet of the overflow valve is very low, and the system oil flows back to the oil tank through the overflow valve at low pressure, achieving unloading.

 

Working Principle

In the quantitative pump throttling regulation system, the quantitative pump provides a constant flow rate, which decreases the flow demand as the system pressure increases. At this point, the overflow valve opens, causing excess flow to overflow back into the oil tank, ensuring that the inlet pressure of the overflow valve and the pump outlet pressure are constant.