What type of valve is specifically designed to drain water in fire sprinkler systems?

The type of valve specifically designed to drain water in fire sprinkler systems is the automatic drain valve. This valve is engineered to facilitate the automatic removal of water from the piping system, typically utilized when the sprinkler systems are being tested, drained, or serviced.

Automatic drain valves function by utilizing the pressure differential in the system; when the system pressure drops, the valve opens, allowing water to exit without requiring manual intervention. This is particularly useful in maintaining system integrity and preventing water stagnation or freezing in areas that could impair the system's operation.

While drain valves are also used to remove water, they usually require manual operation to open. Control valves manage the flow of water in the system but are not specifically designed for draining. Flow control valves regulate the rate of flow but do not have the drainage functionality. The automatic drain valve, by design, directly addresses the need for efficient water drainage in fire sprinkler systems.