Tunnel Dampers (SD20)

Model: SD20

Tunnel Dampers (SD20)
  • Tunnel Smoke Damper

Tunnel Dampers (SD20)

Data :
Minimum size single module: 200 X 350mm
Maximum size single module: 1500 X 1800 mm
Operating pressure: up to 2000 Pa
Operating velocity: 10 m/s
Temperature ratings: 2 hours at 250°C
Electrical Supply: 24 VAC

Description        :

The Model SD20 smoke damper is constructed of standard hot-dip pre-galvanised steel frame full welded at the corner.  The blade is constructed of double-skinned steel plates with stainless steel blade edge seals.  Stainless steel jamb seal is installed on the vertical frame to minimise leakage between blade and frame.  Damper design enables bi-directional flow.  Each blade is equipped with square stainless steel stub shaft and pivot on two-parts bearing.  Interconnecting blade linkages are located outside the air stream and pivot on stainless steel pin.  Damper may be constructed of stainless steel blade and frame.  As a standard, on-off spring-return electric actuator or single acting pneumatic actuator is provided to each damper, number of actuator required depend on the torque required to meet pressure and flow requirement.  The actuator is fast acting and able to close or open the damper over 90o travel in 10 or 20 seconds.  Damper may be installed vertically or horizontally.


  • Robust and modular construction
  • Double skin Airfoil blade withstand high torque without twisting at high pressures and velocity
  • Large module size ensures high free area and lower pressure loss
  • Quality assurance tested
  • Square blade stub shaft prevent slip at the actuator clamp
  • Suitable for Bi-directional flow
  • Low leakage rate less than 0.5% based on approach velocity of 10 m/s and meets UL555s requirement for Class I damper
  • High temperature rating of 250°C for 2 hours
  • High pressure rating to 2000 Pa
  • Fast cycle time – less than 20s for electric actuator and 10s for pneumatic operated damper