The short casing design allows the damper blade to project into the open section of the plenum to minimize overall length. Dampers may also be installed independently within an air shaft or plenum if no fan is installed. Using silicone blade seals, these units are provided with a simple mounting flange for attachment. These dampers may be manufactured in any size between 12 inches ID through 36 inches ID (305 mm to 914mm) and are available in either aluminum or stainless steel. Delta "T" Systems Round Dampers may be closed using either pneumatic or electric actuation. All actuators are suitable for use with CO2, Halon, FM-200 and other pressurized fire suppression systems and are U.S. Coast Guard (162.038/7/0), American Bureau of Shipping, UL (EX-2968) and Factory Mutual type approved.
Pneumatic actuation requires only 70 PSI to release the blade and provide instantaneous spring loaded closure of the air duct. Pneumatic actuation may be achieved through an onboard pneumatic supply line or with an optional Actuator Gas Cylinder (Part Nos. 273-P150/12 or 273-P150/24) pictured below. Dampers may also be manually actuated and reset from outside of the damper housing.
Electric actuation is available in AC and DC power to suit any application. Electrically actuated dampers may be opened and closed manually. A built in fail-safe mode will automatically close the damper in the event of a power loss to the actuator.