Features: The valve stem threads and nut are located outside the bonnet or bracket. During opening and closing, the valve stem moves upward and downward with the gate disc, while the handwheel remains in a fixed position.
Advantages: The valve stem's position allows for intuitive identification of the valve's open or closed state; the valve stem threads are not easily corroded by the media and are easy to lubricate.
Disadvantages: The valve stem requires a considerable amount of space, as it extends when the valve is open.
Applications: Suitable for applications with ample installation space.
Features: The valve stem threads engage with the internal threads of the gate disc. During opening and closing, the handwheel and valve stem rotate together, causing the gate disc to move only up and down; the valve stem does not rise.
Advantages: Compact dimensions and minimal installation space requirements.
Disadvantages: The valve stem position cannot be used to determine the valve opening; the valve stem threads are in direct contact with the medium, susceptible to wear and corrosion, and require a grease injection valve for maintenance.
Applications: Suitable for pipelines with limited space, such as underground pipe networks.
