Manual hoist. The manual opening device of carbon steel valves is called a manual hoist. The manual screw hoist is also called a hand screw hoist. It is a device that operates a plane gate manually. The hoist gate can stay in any position to complete self-locking, which is a very advanced equipment. The screw hoist has the excellent features of light shaking, flexible opening and closing, fast steering and speed change, and manual start.