UL 1820：压缩空气管耐火焰和烟雾性能的防火测试
UL 1820：Standard for Fire Test of Pneumatic Tubing for Flame and Smoke Characteristics
Abstract 摘要
This is a test method for determining values of flame propagation distance and optical smoke density for pneumatic tubing that is to be installed in ducts, plenums, and other spaces used for environmental air. The purpose of this test method is to determine whether the flame-propagation and smoke-generating characteristics of these tubes are in accordance with the provisions of Installation of Air Conditioning and Ventilating Systems, NFPA 90A. Exception No. 3 of Section 2-2.1.2 of NFPA 90A states that pneumatic tubing having the required fire-resistant and low-smoke-producing characteristics are capable of being installed in the space between the ceiling and the floor or roof above, used as an air handling plenum.
