NFPA 1001 Fire Fighter Qualification Practice Exam 2025 – The Comprehensive All-in-One Guide for Success!

The term that refers to the decrease of pressure occurring when water moves through a pipe or hose is friction loss. This phenomenon occurs due to the resistance that the water encounters as it flows through the interior surfaces of the pipe or hose. The roughness of the pipe material, the flow rate, and the length of the pipe all contribute to this loss of pressure.

As water moves through a confined space, such as a hose or a pipe, it experiences various forms of resistance. Friction loss is significant because it affects the overall efficiency of water delivery in firefighting and other applications. Understanding friction loss is crucial for firefighters when calculating the required flow rates and knowing how much pressure will be available at the nozzle after accounting for loss, which is essential for effective firefighting operations.

Other terms such as water hammer, pressure, and flow refer to different concepts within fluid dynamics. Water hammer pertains to the pressure surge when a fluid in motion is forced to stop or change direction suddenly. Pressure is the force exerted by the fluid per unit area, while flow describes the movement of the fluid itself. None of these terms accurately capture the specific aspect of pressure decrease due to the interaction between water and pipe surfaces that friction loss denotes.