Which valve is used to clear particles from the spray bar holes?

The purge valve is specifically designed for the purpose of clearing particles from the spray bar holes. This function is vital in maintaining the integrity and functionality of the spray system, ensuring that obstructions or debris do not impede the flow of water or other extinguishing agents. The use of a purge valve allows for effective cleaning without having to dismantle the system, thus enhancing operational efficiency during firefighting activities.

In contrast, other valves such as relief valves and pressure relief valves serve different purposes, primarily dealing with pressure regulation and safety within the system. Flow control valves are used to manage the rate of flow through a system but do not specifically address the cleaning of spray bar holes. The targeted function of the purge valve makes it the appropriate choice for this task.