How long should it take for an alarm to indicate water flow in a sprinkler system?

The correct duration for an alarm to indicate water flow in a sprinkler system is 90 seconds. This time frame is essential for ensuring that the alarm system accurately detects and signals when water is flowing through the sprinkler system, which is indicative of a potential fire situation.

Setting the threshold at 90 seconds allows for a reasonable response time for the system to distinguish actual water flow from temporary fluctuations that could occur during activation or pressures changes. If the alarm triggered too quickly, it could lead to false alarms during routine testing or minor pressure changes. Conversely, allowing too much time could delay the response to an actual fire, compromising safety.

Overall, adhering to this timing standard is critical for the effective operation of fire sprinkler systems, ensuring they provide an appropriate level of safety and response in the event of a fire.