Back pressure is typically caused by which phenomenon?

• A. Water Hammer
• B. Air In The Pipes
• C. Leaks In The Mainline
• D. Overflow Of The Reservoir

Answer: (D)

Back pressure comes from extra push on the line caused by higher pressure on the discharge side. When a reservoir overflows, the water surface is higher and adds hydrostatic head to the piping. That extra head raises the pressure in the line, which can push back toward the source and create back pressure. The other options describe transient or different pressure effects: water hammer is a sudden, temporary surge from rapid valve changes; air in the pipes can cause flow issues but not sustained back pressure; leaks typically reduce pressure rather than create it. So the overflow of the reservoir is the situation that increases the line pressure enough to produce back pressure.