603.19 Vibration isolation connectors.
MC § 603.19
Vibration isolation connectors in duct systems shall be made of an approved flame-retardant fabric or shall consist of sleeve joints with packing of approved material, each having a maximum flame spread index/rating of 25 and a maximum smoke-developed rating of 50. The fabric shall have a maximum length of 10 inches (254 mm) in the direction of airflow.











