What is the primary cause of failure for water-based fire protection systems?

The primary cause of failure for water-based fire protection systems is often attributed to closed valves. Valves play a critical role in controlling the flow of water through the system. If valves are closed—whether due to incorrect settings, maintenance practices, or human error—the water cannot reach the needed areas during a fire event. This restriction can lead to a complete inability to suppress fire as intended, rendering the entire system ineffective when it is most needed.

While blocked pipes, faulty alarms, and inadequate water supply can indeed contribute to the overall effectiveness of a fire protection system, they don't directly prevent the flow of water as closed valves do. A blocked pipe may hinder flow, but if the valves are open, there may still be some water available. Faulty alarms affect notification and awareness, while an inadequate water supply diminishes effectiveness but is often addressed in system design and hydrant accessibility. Nevertheless, if a valve is closed, the system cannot function at all, making it the most critical failure point.