Central to the fire test procedure is the publicity of duct samples to different fire ailments. A kind A duct sample is subjected to an external flame, though a sort B duct sample faces each exterior and internal fires. The modern development of buildings calls for passive fire security measures https://fireresistingductworkspec68890.theobloggers.com/45966645/the-5-second-trick-for-firesafe-fire-rated-ductwork