Question 265General Subjects - Assistant Engineer
70% to passReferring to the illustrated pneumatically operated diaphragm actuated control valve, what statement is true? Illustration GS-0051
AThe control valve is direct-acting and normally open (NO).
BThe control valve is indirect-acting and normally open (NO).
CThe control valve is direct-acting and normally closed (NC).
DThe control valve is indirect-acting and normally closed (NC).
AI Explanation
The correct answer is A) The control valve is direct-acting and normally open (NO). In a direct-acting pneumatic diaphragm control valve, the valve opens when the pneumatic signal increases, allowing flow through the valve. This is the normal operating condition, so the valve is normally open (NO). The other options are incorrect because an indirect-acting valve would close when the pneumatic signal increases, and a normally closed (NC) valve would be closed in its normal state without an actuating signal.
Related Questions
Q77:Which of the following statements concerning antifriction bearings installed on ... Q634:Which lathe tool shown in the illustration would best be used on a work piece to... Q53:Which of the following liquid level sensors would be most suitable for measuring... Q527:In attempting to start the hydraulic pump drive motor of a horizontal electro-hy... Q438:Referring to the illustrated drawing of the central-station hookup for a hot wat...
Ready to test your knowledge?
Take a General Subjects - Assistant Engineer Practice ExamOfficial Resources