Ducts
FRP SYSTEMS has designed, manufactured, and installed an enormous array of ducting systems. As the field of air pollution is growing at a rapid rate, ducts, scrubbers, and stacks have become a larger portion of our fabricating activity.
The following chart represents industry accepted specifications for fiberglass reinforced polyester round duct dimensions.
Reinforced-Polyester Round Duct Dimensions (1)
I.D. | Wall Thickness (min.) | Allowable Vacuum (2) | Allowable Pressure (2) | Nominal Flange Dia. (O.D.) | Flange Thickness | Bolt Circle Dia. | Bolt Hole Dia. | No. of Bolt Holes |
In. | In. | In. of Water | In. of Water | In. | In. | In. | In. | |
| 2 | 1/8 | 405 | 750 | 6-3/8 | 1/4 | 5 | 7/16 | 4 |
| 3 | 1/8 | 405 | 500 | 7-3/8 | 1/4 | 6 | 7/16 | 4 |
| 4 | 1/8 | 210 | 410 | 8-3/8 | 1/4 | 7 | 7/16 | 4 |
| 6 | 1/8 | 64 | 350 | 10-3/8 | 1/4 | 9 | 7/16 | 8 |
| 8 | 1/8 | 30 | 180 | 12-3/8 | 1/4 | 11 | 7/16 | 8 |
| 10 | 1/8 | 16 | 340 | 14-3/8 | 3/8 | 13 | 7/16 | 12 |
| 12 | 1/8 | 9 | 280 | 16-3/8 | 3/8 | 15 | 7/16 | 12 |
| 14 | 1/8 | 7 | 220 | 18-3/8 | 3/8 | 17 | 7/16 | 12 |
| 16 | 1/8 | 6 | 290 | 20-3/8 | 1/2 | 19 | 7/16 | 16 |
| 18 | 1/8 | 5 | 240 | 22-3/8 | 1/2 | 21 | 7/16 | 16 |
| 20 | 1/8 | 5 | 190 | 24-3/8 | 1/2 | 23 | 7/16 | 20 |
| 24 | 3/16 | 9 | 140 | 28-3/8 | 1/2 | 27 | 7/16 | 20 |
| 30 | 3/16 | 7 | 100 | 34-3/8 | 1/2 | 33 | 7/16 | 28 |
| 36 | 3/16 | 5 | 70 | 40-3/8 | 1/2 | 39 | 7/16 | 32 |
| 42 | 1/4 | 10 | 120 | 46-3/8 | 5/8 | 45 | 7/16 | 36 |
| 48 | 1/4 | 9 | 100 | 54-3/8 | 5/8 | 52 | 9/16 | 44 |
| 54 | 1/4 | 7 | 80 | 60-3/8 | 5/8 | 58 | 9/16 | 44 |
| 60 | 1/4 | 6 | 60 | 66-3/8 | 5/8 | 64 | 9/16 | 52 |
| (1) | 5 to 1 design factor of safety. Also based on 10-foot lengths between stiffener rings for vacuum service. |
| (2) | These ratings are suitable for use up to 180°F (82.2°C) in pressure service and ambient atmospheric temperatures on vacuum service. For ratings at higher temperatures, consult FRP SYSTEMS. |
Sizes over 60" dia. are custom designed to suit service requirements.
Stacks
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FRP SYSTEMS stacks are available in a wide variety of diameters and lengths. Each custom-built stack is designed and engineered to accommodate all loading and service conditions.
13'-0" Dia. Boiler Flue Gas Vent Stacks
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8'-6" Dia x 400' Boiler Vent Stack and Breeching
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