The four-column hydraulic press overflow valve single-stage pressure regulation return path is composed of a定量泵, an overflow valve, and a hydraulic cylinder, forming the most basic pressure regulation circuit. It boasts the following features:

The overflow valve's open pressure can be adjusted through the pressure spring. If the pre-tension of the overflow valve's pressure spring is set, the highest supply pressure can be established. The practical operating pressure of the hydraulic press system is determined by the load.

When the external load pressure is less than the set pressure of the overflow valve, there is no overflow flow at the hydraulic machine's overflow valve. At this moment, the overflow valve acts as a safety valve. When the overflow valve is used individually with a manual overflow valve, the pressure of the overflow valve does not need to be adjusted during a single operation cycle in the system pressure regulation circuit.