To insure proper seating when closing a valve on a tank, what position should the valve be in?

Correct Answer: Option A — closed, opened a half turn, and then closed again

Thermal expansion and contraction of valve components can cause binding or improper seating. Closing the valve fully, then backing it off a half-turn, relieves mechanical stress on the stem and seat. This practice prevents the valve from seizing in the closed position, ensuring it remains operable for future use.