Damper frames are to be constructed of formed 13-gauge galvanized sheet steel, mechanically joined. Linkage is concealed in the right side channel when facing airflow to eliminate noise and friction. Self-lubricating bearings shall be provided.
Damper blade width shall not exceed 8 inches nominal. Blade rotation is to be parallel or opposed as shown on the schedules.
The damper must be rated to operate over a temperature range of -40°F to 200°F (-40°C to 93°C) standard or -40°F to 350°F (-40°C to 177°C) extended temperature.
Damper sizing shall be by the designer in accordance with accepted industry practices to ensure proper system performance. Blank off plates and duct-to-damper transitions may be required.