25-618901 Main relief valve 25/618901 safety valve Hydraulic valve

      As a safety valve to prevent the overload of the hydraulic system the relief valve is used to prevent the overload of the system, the valve is normally closed. When the pressure in front of the valve does not exceed a preset limit, the valve is closed without oil overflow. When the pressure before the valve exceeds this limit value, the valve opens immediately, and the oil flows back to the tank or the low pressure circuit, thus preventing the overload of the hydraulic system. Usually the safety valve is used in the system with variable pump, and the overload pressure controlled by it is generally 8% to 10% higher than the working pressure of the system.

     As an overflow valve, the pressure in the hydraulic system is kept constant in the quantitative pump system, and the throttle element and the load are in parallel. At this time, the valve is usually open, often overflow oil, with the different amount of oil required by the working mechanism, the amount of oil spilt from the valve is large and small, so as to adjust and balance the amount of oil entering the hydraulic system, so that the pressure in the hydraulic system remains constant. However, due to the loss of power in the overflow part, it is generally only used in the system with a low-power quantitative pump. The adjusted pressure of the relief valve should be equal to the working pressure of the system.