液壓升降機的液缸活塞向下運動液壓油經防爆型電磁換向閥進入液缸上端，液缸下端回油經平衡閥、液控單向閥、節流閥、隔爆型電磁換向閥回到油箱。液壓升降機為使重物下降平穩，制動安全可靠，在回油路上設置平衡閥，平衡回路、保持壓力，使下降速度不受重物而變化,由節流閥調節流量，控制升降速度。為使制動安全可靠，防止意外，增加液控單向閥，即液壓鎖，保證在液壓管線意外爆裂時能安全自鎖。安裝了超載聲控報警器，用以區別超載或設備故障。
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.
