Which suction knockout drum condition is listed as a compressor trip cause?

• A. High liquid level in suction knockout drum
• B. Low liquid level in suction knockout drum
• C. High temperature in the suction line
• D. High vibration in the suction system

Answer: (A)

A suction knockout drum is there to strip liquids from the gas before it reaches the compressor, preventing liquid from being carried into the compressor and causing slugging or surge. If the liquid level gets too high, liquids can slip into the gas stream and reach the compressor, forcing protection systems to trip to avoid damage. That high liquid level directly represents a drum condition that can trigger a compressor trip, making it the most relevant and direct cause in this context. The other scenarios—low liquid level, high temperature in the suction line, or high vibration—are issues that may signal problems elsewhere or affect performance, but they do not reflect the drum level condition that would typically cause a trip.