What is the relationship between flow rate and friction loss in a hose line as flow increases?

As flow rate in a hose line increases, friction loss relates directly to the characteristics of fluid dynamics, particularly influenced by the pipe's diameter, surface roughness, and the velocity of the fluid flowing through it. The correct answer states that friction loss increases exponentially, which is founded on the principles described by the Hazen-Williams equation, a commonly used formula in firefighting hydraulics.

According to this relationship, as the flow rate increases, the kinetic energy of the fluid also increases, subsequently raising the velocity. When velocity rises, friction loss increases at a rate that is greater than the increase in flow, resulting in an exponential relationship. This highlights a critical consideration for fire apparatus operators: as they adjust flow rates, they must also account for significant increases in friction loss that can impact overall water supply, pump pressures, and operational effectiveness.

In contrast, friction loss does not remain constant nor does it increase linearly with flow rate, which would imply a direct one-to-one relationship that does not reflect the reality of fluid behavior in hoses.