Read the following passage regarding marine mechanical systems:
Centrifugal pumps in marine coolant loops rely on a high-speed rotating impeller to accelerate fluid outward into a spiral casing called a volute. If the static pressure at the pump suction inlet falls below the vapor pressure of the liquid, localized boiling occurs, producing microscopic vapor bubbles. When these bubbles travel into higher-pressure zones near the impeller discharge vanes, they collapse violently with micro-jet velocities exceeding 1,000 feet per second. This rapid implosion cycle causes severe acoustic chatter, induces mechanical vibration in the pump bearings, and pits the metallic surface of the impeller blades. Cavitation is mitigated primarily by maintaining an adequate Net Positive Suction Head (NPSH) above the liquid's saturation limit through elevated reservoir head pressure or reduced fluid inlet temperatures.
Based on the passage, match each technical statement on the left with its correct textual verification status on the right.
- Vapor bubble collapse generates high-speed micro-jets that pit impeller blades and vibrate bearings.Explicitly confirmed as a direct physical consequence of bubble collapse in high-pressure zones
- Cavitation initiates when inlet static pressure exceeds the liquid's saturation vapor pressure.Directly contradicted by the passage, which states pressure must fall below rather than exceed vapor pressure
- Synthetic lubricating oil is injected into the volute to dissolve forming vapor bubbles.Completely unmentioned and absent from the passage's procedural and mechanical description
- Lowering fluid inlet temperature helps maintain Net Positive Suction Head to mitigate cavitation.Explicitly supported as a valid operational method for maintaining suction head and mitigating cavitation