Which system is described? wastewater flows from a higher elevation to a lower elevation; The process is gravity operated, no energy is consumed in the operation.

Which system is described? wastewater flows from a higher elevation to a lower elevation; The process is gravity operated, no energy is consumed in the operation.

• A. Vacuum
• B. Gravity
• C. Force
• D. Pressure

Answer: (B)

Gravity-driven sewer systems rely on the elevation difference between points in the network. Wastewater moves from higher to lower ground, and the slope of the pipe provides the driving force, so no external energy is used to push the flow in that portion. The design uses the grade, pipe size, and roughness to keep the flow moving at a velocity that prevents solids from settling. If the terrain or elevation change requires, a lift or pump may be used elsewhere to overcome higher elevations, but the segment described operates purely by gravity. This is different from vacuum systems, which use suction, or pressurized/force systems, which rely on pumped pressure to push wastewater through pipes.

Gravity-driven sewer systems rely on the elevation difference between points in the network. Wastewater moves from higher to lower ground, and the slope of the pipe provides the driving force, so no external energy is used to push the flow in that portion. The design uses the grade, pipe size, and roughness to keep the flow moving at a velocity that prevents solids from settling. If the terrain or elevation change requires, a lift or pump may be used elsewhere to overcome higher elevations, but the segment described operates purely by gravity. This is different from vacuum systems, which use suction, or pressurized/force systems, which rely on pumped pressure to push wastewater through pipes.