Zero leakage is specified for which valve?

• A. Oil valve
• B. Ball valve
• C. F/O manifold valve
• D. None of the above

Answer: (C)

When a system requires zero leakage, it’s because even a tiny amount of fuel or oil leaking could create a fire hazard, contaminate the environment, or compromise safety. The fuel/oil manifold sits at the heart of distributing fuel to multiple engine lines, so any leak at the shutoff point could feed fuel into spaces it shouldn’t or cross-contaminate stages of the system. To prevent that, the valve in the F/O manifold is specified to be truly leak-tight when closed, often using high-integrity seals and packing arrangements designed to meet a zero-leakage standard.

Other valves mentioned are typically not designated for zero leakage in this context. An oil valve elsewhere in the system may have acceptable leakage within design limits, and a ball valve can provide a tight shutoff but isn’t universally specified for zero leakage in all service conditions. The safety-critical nature of the fuel/oil manifold makes the zero-leakage requirement appropriate there.