Furnish and install Johnson Controls true round combination fire/smoke dampers at locations shown on plans or as described in schedules.
Damper shrouds are to be constructed of formed 20-gauge galvanized sheet steel.
Damper blades are to be constructed with 1-piece 14-gauge galvanized steel minimum.
Damper performance shall be 1-1/2 hour fire rated under the latest UL Standard 555 and bear a UL label attesting to same.
Damper sizing shall be by the designer in accordance with accepted industry practices to ensure proper system performance.