Suggested Specifications for Round FRP Air Control Dampers
Dampers are installed as shown on plans and per specifications. Damper frame shall be of one-piece construction with a resin rich interior corrosion barrier having a minimum thickness of 100 mils. A structural wall shall consist of alternate layers of chopped strand mat and woven roving to conform to ASME/ANSI RTP-1 and NBS PS 15-69. The overall glass and resin content shall be 40% and 60% by weight, respectively.The fiberglass flange dimensions shall be per NBS PS 15-69 Table 2 for dimensions and bolthole drilling pattern.
The flanges shall have a minimum thickness of 3/4 inch and shall be constructed integral to the cylindrical body of the damper, using the hand lay-up technique per ASME RTP-1-2000 standard Fig 4-7. The distance between the faces of the flanges shall be 6 inches for dampers having a diameter size of 8 inches or less. For all other damper sizes, this distance shall be 12 inches long. The damper blade and stiffeners shall be fabricated using the same resin as the damper frame. The damper blade shall be of unitary construction having no detachable parts or circumferential or wiper blade seals. Damper blade shall be designed to prevent over-rotation without the use of backstops located anywhere in the air stream. 316 SST blade shaft shall be continuous, centered, and custom-milled to fit the operator. Both the damper blade and shaft shall be fully detachable from each other and readily disassembled from the damper body for easy repair or maintenance.
Damper shall have an FRP structural stand-off bracket integrally laminated to the exterior of the body for mounting a worm gear operator.
Damper shall be provided with a self-lubricated hand-wheel driven worm gear operator, as manufactured by:
Operator shall be sized according to required operating torque. Operator shall be coated with corrosion resistant epoxy. All metal parts exposed to the air stream shall be 316 SST. All zero-leakage dampers located at elevations exceeding 6’-6” above finished floor shall, in addition to the hand wheel, be equipped with chain wheel sprockets and appropriately sized chain lengths, as manufactured by:
Chain wheel sprockets shall have integral chain guides to prevent “gagging”.
Annular DanELAST corrosion resistant elastomer sealing seat shall be embedded in the damper body to achieve zero leakage.
Exterior surface of damper shall contain UV inhibitor, and be gel coated or painted with color to match existing ducting.
FRP dampers shall be tested for pressure drop and leakage in accordance with AMCA Standard 500-D. AMCA 500-D leakage tests shall be performed by AMCA certified testing facilities. The leakage rate shall be a maximum of 0 C.F.M per square-foot of cross-sectional area at 30-inches w.g. pressure. The test results shall be submitted for review and approval by the Engineer. The zero-leakage damper shall bear the AMCA seal.
Approved manufacturer of zero-leakage isolation damper shall be:
- Daniel Mechanical – Model: DanELAST 303
- Or equal
Daniel Mechanical Company certifies that the Model 303 dampers shown herein are licensed to bear the AMCA Seal. The ratings shown are based on tests and procedures performed in accordance with AMCA Publication 511 and comply with the requirements of the AMCA Certified Ratings Program. The AMCA Certified Ratings Seal applies to air performance and air leakage ratings.
Test method is per AMCA Standard 500-D-98 Figures 5.3, 5.4 Alternate-6.3, 5.5, & 5.6, 6.5. Data are based on a seating torque of chart listed in-lbsapplied to hold the damper in the closed position. Air leakage is based on operation between 50°F – 104°F.