Pressure Relief Horizontal Air Up 3520-24X10 Smoke-Fire Damper Square collar designed for 20”

Square collar designed for 20” × 20” duct

904 Series Performance Data

Standard Features *Surface mount diffuser * Nylon bushings for easy adjustment and quiet setting of steel blades * Countersunk mounting holes for flush appearance with color matching Phillips posi-drive screws * Double deflection diffuser * Front blades parallel to shortest dimension * Back blades parallel to longest dimension * All blades adjustable allowing 4-way flow adjustment * Soft White Options * 934 O - with recessed screwdriver operated opposed blade damper * 1333 and 1334 Series - stainless steel double deflection * Tamper proof screws * Standard Color or Design Color Finish available on this product

Nylon bushings on adjustable blades prevent metal on metal rattle

HVL Series Submittal

Pressure Relief Horizontal Air Up 3520-24X10 Smoke-Fire Damper Square collar designed for 20”h3. Standard Features * 3510 Vertical mount * 3520 Horizontal mount air up * 3530 Horizontal mount air down * Designed to open with negative or positive pressures for intake or exhaust air * Felt edge blades to hold noise to a minimum * Aluminum construction * Blade to blade linkage * 1 4" pivot pins in nylon busings * Maximum size 24 x 24 * Mill finish h3. Options * Sleeve variations * Mounting flange * Adjustable counter balance to adjust various