Taike valve gate valves can be divided into:
1. Rising stem gate valve: The valve stem nut is placed on the valve cover or bracket. When opening and closing the gate plate, the valve stem nut is rotated to achieve the lifting and lowering of the valve stem. This structure is beneficial to the lubrication of the valve stem and has a significant degree of opening and closing, so it is widely used.
2. Non rising stem gate valve: The valve stem nut is in direct contact with the medium inside the valve body. When opening and closing the gate, it is achieved by rotating the valve rod. The advantage of this structure is that the height of the gate valve always remains unchanged, so the installation space is small, and it is suitable for gate valves with large diameters or limited installation space. This structure should be equipped with an opening/closing indicator to indicate the degree of opening/closing. The disadvantage of this structure is that the valve rod threads not only cannot be lubricated, but also are directly subject to medium erosion and are easily damaged.
The main differences between rising stem gate valves and non rising stem gate valves are:
1. The lifting screw of the non rising stem flange gate valve only rotates without moving up and down. What is exposed is only a rod, and its nut is fixed on the gate plate. The gate plate is lifted by the rotation of the screw, without a visible gantry; The lifting screw of the rising stem flange gate valve is exposed, and the nut is tightly attached to the handwheel and fixed (neither rotating nor axially moving). The gate plate is lifted by rotating the screw. The screw and the gate plate have only relative rotational movement without relative axial displacement, and the appearance is provided with a door-shaped bracket.
2. “Non rising stem valves cannot see the lead screw, while rising stem valves can see the lead screw.”.
3. When a non rising stem valve is opened or closed, the steering wheel and valve stem are connected together and relatively immovable. It is opened or closed by rotating the valve stem at a fixed point to drive the valve flap upward and downward. Rising stem valves raise or lower the valve flap through a threaded transmission between the valve stem and the steering wheel. To put it simply, a rising stem valve is a valve disc that moves up and down together with the valve stem, and the steering wheel is always at a fixed point.
Post time: Mar-29-2023