Referring to the illustrated pneumatically-operated diaphragm-actuated control valve, what statement is true? GS-0051

Correct Answer: Option A — The control valve is direct-acting and normally open (NO).

The valve is direct-acting because the pilot pressure is applied to the top of the diaphragm to close it. It is normally open (NO) because the spring force holds the valve in the open position when there is no pilot air pressure applied to the diaphragm.