This Standard specifies requirements for materials, construction and installation, including some aspects of performance, for flexible duct for air-handling systems in buildings and facilities. It covers - (a) dimensional stability (deformation and deflection) under positive or negative pressure applications and static loads;(b) leakage under positive or negative pressure;(c) support; and(d) fire hazard requirements.This Standard does not cover the following:(i) Noise generation and transmission.(ii) Exposure to damage from - (A) transportation and handling;(B) weather and temperature extremes;(C) flexure cycle;(D) chemical corrosion; and(E) other in-service conditions specific to the installation.(iii) Impact loading, such as -(A) fire;(B) earthquake;(C) sudden stoppage of airflow; and(E) resistance to airflow.