What is the purpose of a suction knockout drum?

• A. It removes gas from the feed stream.
• B. It removes a liquid from the feed stream.
• C. It heats the feed stream.
• D. It filters solids from the feed stream.

Answer: (B)

The suction knockout drum is used to separate and remove liquids that are entrained in a gas stream before it reaches downstream equipment like a pump or compressor. It provides a space where the gas slows and gravity lets the liquid droplets settle to the bottom, allowing only gas to continue onward. This protects the downstream equipment from liquid carryover and potential damage or inefficiency. It’s not about heating, filtering solids, or removing gas itself—the goal is liquid separation from the feed stream.