Hydraulic oil made certain pressure vane pump, the oil filter, flameproof electromagnetic directional valve, throttle valve, hydraulic control one-way valve, balance valve into the lower cylinder, the hydraulic cylinder piston upward movement, improve the weight, the upper cylinder oil return by the flameproof electromagnetic directional valve back to the fuel tank, the rated pressure through the overflow valve adjustment, observing the pressure gauge pressure gauge reading values.
The piston of the cylinder moves downward (i.e. the weight drops). The hydraulic oil enters the upper end of the cylinder through the explosion-proof electromagnetic directional valve, and the back oil of the lower end of the cylinder returns to the oil tank through the balance valve, hydraulic control one-way valve, throttle valve and flameproof electromagnetic directional valve. In order to make the weight fall steadily and brake safely and reliably, a balance valve is set on the oil return circuit to balance the circuit and maintain the pressure so that the falling speed is not changed by the weight. The throttle valve regulates the flow and controls the lifting speed. In order to make the braking safe and reliable, prevent accidents, add the hydraulic control one-way valve, namely the hydraulic lock, to ensure the safe self-lock when the hydraulic pipeline bursts unexpectedly. Overload sound alarm is installed to distinguish overload or equipment failure.