This type of control valve has a threaded portion of the stem visible beyond the yoke when the valve is open and not visible when the valve is closed.

This type of control valve has a threaded portion of the stem visible beyond the yoke when the valve is open and not visible when the valve is closed.

• A. Outside stem & yoke
• B. Post indicator valve
• C. Wall post indicator valve
• D. Post indicator valve assembly

Answer: (A)

In this case the stem design is outside the yoke. An Outside Stem & Yoke valve has the stem passing through the yoke and rising as the valve opens, so the threaded portion of the stem becomes visible above the yoke when open and is hidden when closed. That visual cue— threads showing above the yoke in the open position—is what this option describes. The other choices refer to post-indicator-type valves, where the valve position is shown by a post or indicator rather than by the stem protruding beyond the yoke. They don’t hinge on the stem threading being visible, so they don’t match the described condition.

In this case the stem design is outside the yoke. An Outside Stem & Yoke valve has the stem passing through the yoke and rising as the valve opens, so the threaded portion of the stem becomes visible above the yoke when open and is hidden when closed. That visual cue— threads showing above the yoke in the open position—is what this option describes.

The other choices refer to post-indicator-type valves, where the valve position is shown by a post or indicator rather than by the stem protruding beyond the yoke. They don’t hinge on the stem threading being visible, so they don’t match the described condition.