The difference between rising stem gate valve and dark stem gate valve

1. The lead screw can be seen in the bright stem gate valve, but the lead screw cannot be seen in the concealed stem gate valve;
2. The rising stem gate valve lifts or lowers the disc through the thread transmission of the valve stem and the steering wheel; the steering wheel and the valve stem of the dark stem gate valve are connected together and relatively immobile when the stem gate valve is switched on and off, and it is achieved by rotating the valve stem at a fixed point. Drive the valve disc to lift up and down to complete the opening and closing;
3. The transmission thread of the hidden stem gate valve is located inside the valve body. During the opening and closing process, the valve stem only rotates, and the gate plate rises and falls in the valve body; the valve stem of the rising stem gate valve drives the gate plate to lift together, and the valve stem on the valve stem The transmission thread is outside the valve body, and the opening and closing and position of the gate can be visually judged according to the movement direction and position of the valve stem;
4. The height of the concealed stem gate valve is small; the rising stem gate valve requires a larger installation space;
5. The structure of the rising stem gate valve is beneficial to the lubrication of the stem, and the degree of opening and closing is obvious; the thread of the stem of the concealed stem gate valve is not only not smooth, but also directly bears the corrosion of the medium and is easily damaged. Therefore, rising stem gate valves are more widely used.