Under what condition must friction loss be calculated for hose?

Calculating friction loss for hose is particularly important when the hose is used to transport water up an elevation. This is because elevation contributes to the overall resistance opposing the flow of water, creating additional pressure required to push the water upwards. When water is moved vertically, the gravitational force impacts the pressure needed to maintain an effective flow rate, making it essential to account for this elevation gain in the friction loss calculations.

Understanding this factor is crucial for fireground operations as it ensures that there is sufficient pressure at the nozzle to deliver the required flow for firefighting efforts. Without calculating both friction loss and the elevation increase, a firefighter may underestimate the necessary pump pressure, potentially leading to inadequate water supply at the fire scene.

While other conditions related to hose use, such as hose diameter, pump pressure, and flow rate, also influence friction loss calculations, the primary factor that necessitates careful calculation in this context is the elevation change.