What is the purpose of bleeder valves?

Bleeder valves are specifically designed to allow air to escape from the water lines of fire apparatus during the process of charging the hose. When a hose is being filled with water, any trapped air needs to be released to ensure that the hose is completely filled and that water can flow freely without restriction.

Without using a bleeder valve, air could remain in the lines, leading to inefficiencies such as "water hammer," where air pockets can cause surges and pressure fluctuations that might damage the system or affect firefighting operations. By allowing air to bleed off, these valves help maintain a consistent flow of water and ensure that the hose is primed and ready for use when it matters most.

In contrast, the other options don’t accurately represent the primary function of bleeder valves. Breaking hoses into smaller lines, shutting off water supply to the pump, or managing excess water are not the intended uses of a bleeder valve.