In what position must the stem of an operational split wedge gate valve be?

In the context of split wedge gate valves, the stem must be in a vertical position when the valve is operational. This design is primarily to ensure optimal sealing and to prevent any potential leakage when the valve is closed. A vertical stem position allows for uniform seating of the wedges against the valve body, creating an effective barrier against the flow of liquid or gas.

Moreover, a vertical position is crucial for the mechanical advantage it provides in the opening and closing of the valve. When the stem is vertical, the force applied to the handle translates efficiently into lifting the wedges, making operation easier and reducing wear on the components. This configuration also aligns with industry standards and practices for gate valves, ensuring safety and reliability in both residential and industrial applications.

Choosing any other position, such as horizontal or diagonal, could lead to improper sealing, increased friction in the valve's operation, and potential failure during use. Hence, maintaining the vertical alignment of the stem is essential for the reliable and efficient functioning of a split wedge gate valve.