What condition causes friction loss in fire hoses?

Friction loss in fire hoses is significantly influenced by the turbulence of water. When water flows through a hose, it encounters resistance due to the internal surface roughness of the hose and the interaction between the water molecules. As flow rates increase, the water can become turbulent, particularly in sections of hose that are narrower or have bends and turns. This turbulence disrupts the smooth flow of water, increasing the friction loss, which means that more pressure is required to maintain the desired flow rate.

In situations of turbulence, energy is lost as the water swirls and creates additional friction with the hose walls, contributing to diminished efficiency in the system. Understanding this concept is crucial for fire apparatus engineers, as it informs their decision-making about hose selection, layout, and operational tactics to manage and minimize pressure losses effectively during firefighting operations.