Which term is designed for inserting cleaning tools, not for personnel entry?

• A. Gravity Main
• B. Inverted Siphons
• C. Cleanout
• D. Outfall Line

Answer: (C)

Access points that let maintenance crews reach the inside of a pipe to clear blockages with tools are designed for cleaning use. The term that fits this purpose is a cleanout, which is a short pipe with a removable cap that opens directly into the sewer line so plumbers can insert snakes or other cleaning equipment and inspect the line. It isn’t meant for people to enter because cleanouts are typically narrow and carry hazardous gases, making entry unsafe; larger access points like manholes are used when someone needs to go inside. By contrast, a gravity main is the main flow line that relies on gravity to move waste, an inverted siphon is a section that uses a siphon effect to pass under an obstacle, and an outfall line is the pipe that carries treated wastewater away to a sewer or body of water.