In NFPA 13 D standard, what is the minimum operating pressure on any sprinkler?

In the NFPA 13D standard, the minimum operating pressure for any sprinkler is established at seven psi or higher. This pressure is essential for ensuring that the sprinkler system can effectively discharge water when activated, thereby providing adequate fire protection. The minimum pressure allows the system to achieve sufficient flow rates and coverage necessary to suppress or control a fire.

Establishing this minimum standard helps ensure that sprinklers can perform reliably under expected conditions, promoting safety and compliance with fire protection regulations. Moreover, higher pressures might be required for certain installations or specific types of sprinklers to account for variations in system design or building configurations, but the baseline requirement is key in maintaining an effective fire protection system.