Manual Volume Control Damper

1. Overview of Manual Volume Damper

1.1

Manual volume damper belongs to general‑ventilation damper, fitted with manual adjusting handle for on‑site manual air‑volume regulation in HVAC ductwork, as well as full opening and full closing of duct. The handle drives blade rotation to change ventilation cross‑section. The handle can be locked after commissioning to maintain fixed airflow, widely used for air balancing during system commissioning. Available in full range of rectangular and round sizes.

‑ Manual Opposed‑blade Multi‑louver Damper: Adjacent blades rotate oppositely for uniform air‑volume adjustment, widely used for rectangular ducts, equipped with graduated locking handle. ‑ Manual Parallel‑blade Multi‑louver Damper: Blades rotate in same direction, mainly for duct on‑off and coarse air‑volume adjustment. ‑ Manual Butterfly Damper: Single rotating disc for round ducts, simple structure for duct cut‑off and rough regulation.

1.2 Product Classification

‑ By structural shape: Rectangular type, Round type. ‑ By blade type: Opposed‑blade multi‑louver, Parallel‑blade multi‑louver, Butterfly damper.

2. Operating Conditions for Manual Volume Damper

Operating temperature: ‑20 ℃ ~ +80 ℃ Relative humidity: less than 90% Medium condition: General ventilation air; anti‑corrosion version for dust‑free corrosive gas.

Power supply: No power required.

3. Manual Volume Damper Configuration

3.1 Standard Components

‑ Damper body ‑ Blade assembly ‑ Rotating shaft ‑ Graduated locking manual handle ‑ Connecting flange

3.2 Optional Accessories (please specify requirements upon order)

‑ Sealing gasket ‑ Anti‑corrosion coating ‑ FRP anti‑corrosion damper body

4. Manufacturing Process of Manual Volume Damper

4.1

Damper body and blades are fabricated from galvanized steel sheet. Blades are fitted with stiffeners for higher rigidity. Rotating shafts adopt wear‑resistant bushings for smooth jitter‑free rotation. Manual handle with angle scale for position locking after adjustment. Anti‑corrosion dampers adopt anti‑corrosion coating or FRP construction.

4.2

Damper flange is integrally bent to form flat mating surface for easy duct connection.