液压升降机的液缸活塞向下运动液压油经防爆型电磁换向阀进入液缸上端，液缸下端回油经平衡阀、液控单向阀、节流阀、隔爆型电磁换向阀回到油箱。液压升降机为使重物下降平稳，制动安全可靠，在回油路上设置平衡阀，平衡回路、保持压力，使下降速度不受重物而变化,由节流阀调节流量，控制升降速度。为使制动安全可靠，防止意外，增加液控单向阀，即液压锁，保证在液压管线意外爆裂时能安全自锁。安装了超载声控报警器，用以区别超载或设备故障。
lift cylinder piston downward movement of the hydraulic oil by explosion-proof solenoid valve into the upper end of the hydraulic cylinder, hydraulic cylinder through the lower back to the oil balance valve, check valve, throttle, explosion-proof solenoid valve back to the tank. Fixed lift heavy objects fall to make a smooth, safe and reliable braking, set the balancing valve, balancing loop back to the oil on the road, keep up the pressure, so that the rate of decline from the weight change, the throttle valve regulates the flow, speed control movements. In order to secure the brake to prevent accidents and increase check valve, namely hydraulic lock, ensure that when an unexpected burst hydraulic lines can safely self-locking. Installed voice alarm overload, overload or equipment failure to distinguish.
