Which term describes the pressure remaining after friction and gravity have been accounted for in the network?

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

Answer: (A)

In a pipe network, energy from the source is spent overcoming friction and lifting or lowering fluid through elevation changes. The pressure energy that’s left after accounting for these losses is the residual pressure. It’s the pressure still available to drive flow further in the network once all frictional and gravitational losses have been subtracted. This helps indicate whether downstream points will receive enough pressure. It differs from static pressure, which is simply the instantaneous pressure at a point without reference to losses, and from terms that describe other energy components rather than the remaining pressure after losses.