When the diameter of the hose is increased, what happens to the friction loss?

When the diameter of the hose is increased, the friction loss decreases due to the physics of fluid dynamics. Friction loss in hoses occurs when water flows through them and encounters resistance against the hose walls. This resistance is influenced by the hose diameter: a larger diameter provides a wider pathway for the water to flow.

With a larger diameter, the same volume of water can flow at a lower velocity, which reduces the friction against the inner walls of the hose. According to the Hazen-Williams equation, which is commonly used for calculating friction loss in pipes and hoses, friction loss is inversely proportional to the diameter raised to a certain power. Specifically, doubling the diameter can significantly decrease the friction loss, making it much more efficient for conveying water. This principle is crucial for fire officers and firefighters to understand, as it directly impacts water supply operations and the ability to manage fire effectively.