The HTD-636 is a heavy duty industrial air control damper qualified for use in tunnel and transit systems. This model has a double flanged frame and features mechanically fastened silicone blade seals and stainless steel jamb seals.

• Meets the requirements of NFPA-130, 502, and UL 555S
• Fire Rating: BS476 two hours and approved for fire partitions of four hours or less where British Standards are required
• Blade type: Fire-rated fabricated airfoil
• Pressure: Up to 24 in. wg
• Velocity: Up to 4000 fpm
• Temperature: 482°F for 2 hours (NFPA-130, 502)
• Fatigue Cycles: 8 million reverse cycles at 24 in. wg