Friction loss in hose, pipes, and appliances is:

• A. The term used to describe both pressure loss and pressure gain
• B. The position of an object above or below sea level
• C. The center line of the pump or the bottom of a static water supply source above or below ground level
• D. Pressure loss due to friction

Answer: (D)

Friction loss is the pressure drop that occurs as water flows through hoses, pipes, and appliances due to friction against the interior surfaces. It’s the key factor that reduces available pressure in a hose line and depends on how much water is moving, the size and length of the hose, and the fittings involved. This is why it’s the best description: it specifically describes a loss of pressure caused by friction, not a pressure gain, and it isn’t about elevation or the physical position of the line. In practice, you account for friction loss to determine the pump discharge pressure needed to overcome it (along with any elevation losses) to reach the desired nozzle pressure.