What must a relay pumper have to discharge air when an intake line is charged with water?

A bleeder valve is essential for a relay pumper to effectively discharge air when an intake line is charged with water. This valve allows for the release of trapped air in the lines, which can prevent the pump from functioning properly. When the intake line is filled with water, air can become trapped, causing issues such as cavitation or reduced pumper efficiency. By utilizing a bleeder valve, operators can ensure that this air is expelled, allowing for a smooth and efficient flow of water into the pump and preventing operational problems.

The presence of a bleeder valve is particularly important in maintaining the effectiveness of the relay pumper, as it aids in establishing a prime and maintaining pump operation without interruptions caused by air locks. This functionality is crucial in firefighting scenarios where every second counts, and improper air management can lead to delays or failure in delivering water to the fireground.