What is the main purpose of an auxiliary drain valve in a fire protection system?

The main purpose of an auxiliary drain valve in a fire protection system is to drain trapped water. This is critical for maintaining the system's efficiency and integrity. During installation or maintenance, water can become trapped in low points of the piping system. If this water is not drained, it can lead to issues such as freezing in colder climates or creating unwanted pressure points. By using the auxiliary drain valve, technicians can safely and effectively remove this trapped water, ensuring that the fire protection system is operating under optimal conditions.

Other functions, such as filling the system with water, inspecting pipe conditions, or connecting to the municipal water supply, are handled by different components of the fire protection system and are not the primary roles of an auxiliary drain valve. Therefore, focusing on its purpose in removing trapped water highlights the importance of maintaining the system's functionality and preventing potential hazards.