Pressure remaining at a given point in a water supply system while water is flowing?

Pressure remaining at a given point in a water supply system while water is flowing?

• A. Static Pressure
• B. Pitot Tube
• C. Cavitation
• D. Residual Pressure

Answer: (D)

The pressure remaining at a point while water is flowing is residual pressure. When water moves through a system, friction, fittings, and elevation changes steal some of the energy, so the pressure at a given location drops from the static value. The remaining pressure under flow—the residual pressure—tells you how much pressure is still available to push water to outlets like hydrants or sprinklers. Static pressure is the pressure you’d measure with no flow, so it doesn’t describe flowing conditions. A Pitot tube measures velocity pressure to determine flow rate, not the actual pressure in the system at a point during flow. Cavitation involves vapor bubble formation when pressure gets too low, which is a different phenomenon entirely.

The pressure remaining at a point while water is flowing is residual pressure. When water moves through a system, friction, fittings, and elevation changes steal some of the energy, so the pressure at a given location drops from the static value. The remaining pressure under flow—the residual pressure—tells you how much pressure is still available to push water to outlets like hydrants or sprinklers.

Static pressure is the pressure you’d measure with no flow, so it doesn’t describe flowing conditions. A Pitot tube measures velocity pressure to determine flow rate, not the actual pressure in the system at a point during flow. Cavitation involves vapor bubble formation when pressure gets too low, which is a different phenomenon entirely.