UL 793:2017-03 Automatically Operated Roof Vents for Smoke and Heat

UL 793:2017-03 Automatically Operated Roof Vents for Smoke and Heat. 1.1 These requirements cover automatically operated roof vents for smoke and heat that fall into two general categories: mechanically-opened and gravity-opened. Mechanically-opened vents consist primarily of a body frame. one or more damper covers and hatches, and operating mechanisms which generally include a heat responsive device and spring(s). Gravity-opened vents consist primarily of a body frame and nonmetallic drop-out panel. The vents covered by these requirements are operated manually or automatically in the event of fire to remove smoke and heat from the building. Automatic operation does not depend on electrical power or other energy sources that may be interrupted during a fire, but rather depends upon operation of a heat responsive device or on the action of a plastic cover shrinking and falling from place due to fire exposure, or the like. These vents are not intended for use as general purpose building ventilation devices. 2 General 2.1 Units of measurement 2.1.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 2.2 References 2.2.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. 2.3 Components 2.3.1 Except as indicated in 2.3.2, a component of a product covered by this standard shall comply with the requirements for that component. 2.3.2 A component is not required to comply with a specific requirement that: a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard, or b) Is superseded by a requirement in this standard. 2.3.3 A component shall be used in accordance with its rating established for the intended conditions of use. 2.3.4 Specific components are incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specified limits, and shall be used only under those specific conditions.UL 793 pdf download.