Which term describes the energy stored to push water through pipes and hoses?

• A. Static pressure
• B. Flow pressure
• C. Head pressure
• D. Residual pressure

Answer: (A)

Energy available to push water through pipes comes from the pressure inside the fluid. When water is held in a pipe or hose, that pressure stores energy that can be used to do work on the moving water. This stored energy per unit volume is the static pressure, the part of the fluid’s energy that acts to push water through the system and overcome friction and elevation losses. That’s why static pressure is the best fit for describing the energy stored to push water through pipes and hoses. The other terms don’t capture this stored, push-driving energy: residual pressure is what’s left after flow has ceased, and head concepts describe total energy per unit weight (not just the stored pressure energy), while flow pressure isn’t the standard label for this stored energy.