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UL 1478A Ed. 2-2025
Pressure Relief Valves for Sprinkler Systems - Published Date: June 9, 2025
1.1 These requirements cover pressure relief valves intended for use in sprinkler systems for fire protection service to relieve excessive pressures in valve trim, downstream of a pressure reducing valve or caused by thermal expansion with a sprinkler system. These valves may also be suitable for use as a circulation relief valve for a fire pump based its relief valve pressure setting and inlet size. 1.2 Requirements for installation of these valves are included in the Standard for the Installation of Sprinkler Systems, NFPA 13 and the Installation of Stationary Fire Pumps, NFPA 20, as applicable.
Underwriters Laboratories [ul]