SECTION 033000 - CAST-IN-PLACE CONCRETE

Sludge Treatment Project Engineered Container Retrieval and Transfer System January 2012
N. Accessories:
1. Auxiliary switches for position indication.
2. Momentary test switch remote mounted.
2.7 COUNTERBALANCED BACKDRAFT DAMPERS
A. Manufacturers: Subject to compliance with requirements, available manufacturers offering
products that may be incorporated into the Work include, but are not limited to, the following:
1. American Warming and Ventilating; a division of Mestek, Inc.
2. Greenheck Fan Corporation.
3. Ruskin Company.
B. Low-leakage rating, with linkage outside airstream, and bearing AMCA's Certified Ratings Seal
for both air performance and air leakage.
C. Frames:
1. 8 inches by 2 inch flange channel.
2. Type 304 Stainless-steel channels, min 14 ga (0.075 inch thick).
3. Mitered and welded corners.
4. Bolt Holes both flanges
D. Blades:
1. Multiple blade with maximum blade width of 7 inches.
2. Parallel blade design.
3. Type 304 Stainless steel.
4. 16 ga (0.059 inch thick).
5. Blade Edging: EPDM mechanically attached blade edge.
6. Jamb Seals: Fitted with EPDM seal located directly behind blade edge.
E. Blade Axles: 1/2-inch-diameter; stainless steel or nonferrous metal; blade-linkage hardware of
zinc-plated steel and brass; ends sealed against blade bearings.
1. Operating Temperature Range: From minus 40 to plus 200 deg F.
F. Counterbalance located out of airstream.
G. Bearings:
1. Ball bearings pressed into frame.
H. Performance Data:
1. Maximum System Pressure: 10 inches w.g.
2. Maximum System Velocity: 3,000 feet per minute.
3. Leakage with Seals: Based on pressure differential of 1 inch w.g.
a. Percent of Maximum Flow: 0.57.
b. Leakage 17 cfm/ft 2 .
Contract 44577 KW Annex - Rev. E 44577-CSI-SPEC-001 233300 - 8