The 2000 psi isolation valve is fail safe _______, and remains _______ unless an isolation occurs.

• A. CLOSED; OPEN
• B. CLOSED; CLOSED
• C. OPEN; OPEN
• D. OPEN; CLOSED

Answer: (C)

The important idea here is how a fail-safe valve behaves when power or control is lost and how it operates during an isolation event. This isolation valve is designed to be fail-safe open, meaning if something goes wrong (loss of power or fault), the valve defaults to the open position to keep hydraulic flow unblocked rather than trapping pressure. Under normal conditions it stays open, and only closes when an isolation occurs to stop flow to a particular section of the system. So describing it as fail-safe open and remaining open unless an isolation occurs captures both the safe default state and the intended action during isolation.