Model SD-25R

Smoke Damper
Round Blade

The SD-24R smoke damper employsa single round blade for point-of-origin control of smoke in static and dynamic smoke management systems. This unique damper comes standard with mounting plates for interface to round or square openings in masonry, metal stud or wood stud assemblies and is ideal for all round duct applications. The SD-25R, standard construction,  is qualified to 2,000 ft/min (10.2 m/s) and 4 in.wg. (1.0 kPa) at 250^oF (177^oC). Optional construction is qualified to 3,000 fpm (15.3 m/s) and 4 in. wg. (1.0 kPa) and may be installed in, or adjacent to vertical walls or partitions, or horizontally in, or adjacent to floors or assemblies.

Standard Construction

Frame: Integral 16" x 20 ga. (203 x 1.0) galvanized steel with reinforcing beads.
Blades: 14 ga. (2.0) equivalent galvanized steel - round.
Axles: 1/2" (13) diameter plated steel, D<8 (203), 3/4" (19), D≥8 (203).
Linkage: In the air-stream.
Bearings: Bronze oilite, sleeve-type.
Seals: Silicone blade edge seal.
Actuator: 120 VAC, power-open, spring-close, external mount. View Actuators.   
Minimum Size: 6" Ø (152 Ø)
Maximum Size: 24" Ø (610 Ø)

Ratings

UL 555S Leakage Class: 1 
Maximum Temperature: 350^oF (177^oC)

UL 555S Listing: R14981
CSFM Listing: 3230-1404:111
New York City MEA Listing: 295-98-E
Meets NFPA Standards: 90A, 92A, 92B and 101
Meets Building Code Standards: IBC, NBC, NFPA, SBC and UBC