Is it true that ESFR sprinklers shall be used only in wet pipe systems?

ESFR (Early Suppression, Fast Response) sprinklers are designed to provide early and effective suppression of high-challenge fires, especially in rack storage applications. The specification that ESFR sprinklers shall be used only in wet pipe systems is based on their operational mechanism. Wet pipe systems use water-filled pipes that automatically discharge the water from the sprinklers when the heat from a fire triggers them.

This approach ensures rapid delivery of a significant volume of water, which is essential for the performance of ESFR sprinklers, as their design relies on quick activation and the immediate availability of water under pressure. Utilizing them in a wet pipe system optimizes their effectiveness, and NFPA (National Fire Protection Association) standards reinforce this requirement to ensure safety and operational efficiency in fire suppression systems.

Other configurations, such as dry pipe systems or pre-action systems, may not provide the same level of responsiveness and water delivery, thus compromising the performance of ESFR sprinklers. This principle is why the use of ESFR sprinklers is specifically limited to wet pipe systems, ensuring they can perform effectively when needed.