Viking Early Suppression Fast Response (ESFR) Dry Pendent Sprinkler VK502 is a fast response fusible element type sprinkler designed for use in storage areas subject to freezing and supplied from a wet system in an adjacent heated area. With a 14.0 (202 metric*) nominal K-Factor and special deflector, this sprinkler produces large, high-momentum water droplets in a hemispheric pattern below the deflector. This permits penetration of the fire plume and direct wetting of the burning fuel surface while cooling the atmosphere early in the development of a high-challenge fire. The dry ESFR sprinkler consists of a fusible element style ESFR sprinkler permanently secured to a special supply nipple. The sprinkler assembly features a sealed brass inlet that’s grooved or threaded. Also included with the ESFR dry sprinkler are two insulating boot assemblies to help seal the clearance space around the dry sprinkler barrel. When properly installed, the seal decreases the potential for leakage of air through the opening in the ceiling and consequent formation of condensate around the sprinkler connection on the system piping. In freezer installations, condensation can lead to ice build-up, which could inhibit sprinkler operation or cause premature sprinkler operation. The dry sprinkler boot assembly is intended to slow the exchange of air between the inside and outside of the freezer (or any dry sprinkler installation) to help prevent humidity and temperature differential in the area around the sprinkler. The rubber seal is designed with a material that will not drip when exposed to open flame. This protects the deflector from acquiring material that would impede its water distribution characteristics.