What is a primary function of a hose liner?

A primary function of a hose liner is to reduce friction loss. When water flows through a fire hose, friction occurs between the water and the internal walls of the hose. This friction can result in a loss of pressure, which may hinder the efficient delivery of water to the nozzle and ultimately affect firefighting efforts. Hose liners are designed to create a smoother inner surface, minimizing this friction and allowing for a more efficient flow of water. This capability is crucial in firefighting situations where maximizing water flow can be critical to extinguishing fires effectively and safely.

The other options pertain to various aspects of hose functionality but do not specifically capture the essence of what a hose liner is primarily designed to accomplish. For instance, enhancing flexibility refers more to the material and construction of the hose rather than the role of the liner itself. Similarly, while containing contaminants is important, it generally relates to the overall construction of the hose rather than the function of a dedicated liner. Therefore, focusing on friction loss highlights the unique role that a hose liner plays in firefighting operations.