PDF Standards UL 521
Heat Detectors for Fire Protective Signaling Systems
standard by Underwriters Laboratories, 02/19/1999
Heat Detectors for Fire Protective Signaling Systems
standard by Underwriters Laboratories, 02/19/1999
Standard for Luminaires
standard by Underwriters Laboratories, 03/26/2021
Strut-Type Channel Raceways and Fittings
standard by Underwriters Laboratories, 04/14/2004
Pressure Regulating Valves for LP-Gas
standard by Underwriters Laboratories, 05/25/2012
Special-Purpose Metal Containers
standard by Underwriters Laboratories, 02/03/2005
Test for Sharpness of Edges on Equipment
standard by Underwriters Laboratories, 04/21/2015
Leakage Current for Appliances
standard by Underwriters Laboratories, 07/31/2017
Switches for Appliances – Part 1-1: Requirements for Mechanical Switches
standard by Underwriters Laboratories, 11/03/2017
Standard for Pressure Relief Valves for Sprinkler Systems
standard by Underwriters Laboratories, 05/20/2013
Water Fire Extinguishers
standard by Underwriters Laboratories, 02/28/2005