Rising Stem Vs Non-Rising Stem Gate Valves: A Comparative Analysis of Handwheel Operating Torque Design Standards

Rising Stem Gate Valves

Design and Operation

• Structure: Rising stem gate valves feature a visible stem that moves up and down as the handwheel is turned. The stem is connected to the gate, and as the handwheel is rotated, the gate moves vertically to open or close the valve.

• Operation: The handwheel is typically connected to the stem via a threaded connection. Turning the handwheel causes the stem to move linearly, lifting or lowering the gate. This movement is visible, providing a clear indication of the valve's position.

Advantages

• Visual Indication: The visible movement of the stem provides a clear indication of the valve's position, making it easier to monitor and control.

• Ease of Operation: The linear movement of the stem often requires less force to operate, making it easier to open and close the valve.

• Reduced Wear: The design reduces wear on the stem and gate, extending the valve's lifespan.

Non-Rising Stem Gate Valves

Design and Operation

• Structure: Non-rising stem gate valves feature a stem that rotates but does not move vertically. The stem is connected to the gate via a threaded connection inside the valve body. As the handwheel is turned, the gate moves vertically within the valve body, but the stem remains stationary.

• Operation: The handwheel is connected to the stem via a threaded connection. Turning the handwheel causes the gate to move vertically within the valve body, opening or closing the valve. The position of the valve is indicated by a pointer or indicator on the handwheel.

Advantages

• Space Efficiency: The stationary stem design requires less vertical space, making it suitable for installations with limited space.

• Simplicity: The design is simpler, which can reduce manufacturing and maintenance costs.

• Durability: The stationary stem is less susceptible to wear and damage from external factors.

Comparative Analysis

Key Differences