What is a main item that applies to the maintenance of a cold water service valve?

• A. Check operation
• B. Lubricate spindle
• C. Replace o-ring
• D. Tighten nut

Answer: (A)

Regularly exercising a cold water service valve—turning it fully on and off—keeps the stem and seat from sticking and verifies the valve can shut off cleanly. This check reveals if the valve is hard to turn, binding, or leaking, so you catch problems before they become leaks or failures. Other actions like lubricating the spindle, replacing an o‑ring, or tightening the nut are corrective or condition-based steps used when a specific issue is found. Lubrication isn’t always required or recommended for potable water valves and could contaminate the water if misapplied; an o‑ring is replaced when worn or leaky, not as routine maintenance; tightening the nut may affect packing and sealing and should be done only to address a specific issue. So the main maintenance item is to check operation by exercising the valve regularly.