What is the maximum number of automatic sprinklers that can be controlled by a single non-interlock pre-action valve?

The capacity of a single non-interlock pre-action valve to control automatic sprinklers is established by the National Fire Protection Association (NFPA) standards. Specifically, non-interlock pre-action systems are designed for specific applications where the controlled area must remain dry until the system is activated.

The limit of 1,000 sprinklers is based on the operational and safety considerations of the valve’s performance. This figure ensures that in the event of accidental activation or a fire, the system can efficiently deliver water to all the connected sprinklers without compromising system integrity or response time. This maximum number also takes into account factors such as water supply, the valve's design, and hydraulic characteristics, ensuring that the system operates effectively under expected conditions.

Other numbers, such as 500, 750, or 1500, do not align with the guidelines established in NFPA standards, which specify 1,000 as the optimal limit for maintaining reliability and safety in these systems. Therefore, the correct answer underscores the importance of adhering to established safety protocols and design limitations in sprinkler system installations.