The stem is visible in the open stem gate valve and not in the dark stem gate valve.
The paddle gate valve is used to lift or lower the disc through a threaded drive between the stem and the steering wheel. When the non-rising stem gate valve is on and off, the steering wheel and the stem are connected together and relatively fixed. It drives the valve plate up and down by turning the stem at a fixed point.
The drive thread of non-rising stem gate valve is located in the valve body. In the opening and closing process, the stem only rotates and the valve plate rises or falls in the valve body. The stem of the rising stem gate valve drives the valve plate up and down together. The drive thread on the stem is outside the valve body, and the opening and closing position of the valve plate can be judged intuitively according to the movement direction and position of the stem. The height of non-rising stem gate valve is small; Large installation space is required for rising stem gate valve;
The structure of the stem gate valve is favorable to the lubrication of the stem, and the degree of opening and closing is obvious. Stem threads of non-rising stem gate valves are not only non-lubricated, but also subject to direct dielectric erosion and damage.