Ultimate Airflow Efficiency
FRP is created through a process of combining wound filament and phenolic resin to maximize strength. In order to guarantee low flow resistance and increase power savings, each FRP section features a smooth, low friction surface for airflow, and are built to withstand high positive and negative pressures. Sections can also be fabricated with either flanged connections or bell and spigot connections which feature internal rubber gaskets to prevent leakage.
Phenolic Resin & Filament
Smooth, Low Friction Interior Surface
Our improved joint seal eliminates leakage.
Round or Oval Ducts available
NEW GENERATION OF FRP RIGID DUCTING
Norvent Ventilation Ltd. is dedicated to providing quality products to the mining and tunnelling industries. Through continued research and development we have introduced innovative improvements to the manufacturing process for our filament wound rigid pipe. We take pride in announcing the precedent setting K Factor and Air Loss results as the best in our industry.
Construction
- Filament wound rigid ducting.
- Smooth inner surface – low friction loss.
- Joints are manufactured with internal rubber gaskets to prevent leakage
- Airtight joints.
- Easy installation – guaranteed fit.
- Strong nylon straps with D Rings for interlocking of sections
- Suspension straps are available for added strength and safety.
Advantages & Features
- Upholds its integrity in a fire longer than metals; will operate up to 200°C while maintaining stability.
- Fire resistant according to ASTM E-162 with flame spread index of less than 25.
- Will not promote or sustain combustion. Thermal conductivity is much lower than metals 0.20 – 0.24 w/m/k.3. Antistatic properties 10³ ohms @ 1% wt. surface resistivity.
- Bell/Spigot ensures a safer installation – eliminating pinch points (flanged joints are available).
- Joints – Bell and Spigot can move 7 degrees right to left and up or down for direction.
- Available with a flanged end. Flanges are installed prior to filament winding. Flanged minimizes leakage and provides stabilization from high shock waves during the blasting cycle. V-lock couplings speed up installation.
- Less than half the weight of steel. For example a Rigid Oval (36×62) x 20’ = 400 lbs approximately, whereas the identical sized steel vent would be approximately 1,000 lbs.
- Low installation cost due to lightweight pipe.
- Joints are manufactured complete with internal rubber gaskets to prevent leakage and reduce resistance at the joints.
- When subject to loading or impact, springs back to shape (memory), while metal will dent and leak and may start to recoil.
- Smooth interior to guarantee low flow resistance and therefore an increase in power savings.
- EMR/CSA and MSHA approved for underground.
- Can withstand high positive and negative pressures.
- Acid mine water resistant and rot proof.
- Long service life.
FRP Rigid Ventilation Ducting
Phenolic Resin: The Manufacturing Difference That Results in a Better Product
Rigid Ventilation Ducting is manufactured for use in mining and tunnelling applications. We combine a filament winding process and phenolic resin for maximum rigid duct strength. One of the advantages of phenolic resin is its excellent acid resistance which is a result of the acid cure process. Because phenolic resin is water based and polyester is oil based, phenolic resin is inherently flame resistant, and no fire inhibitors are added. These inhibitors detract from the strength of polyester resins making them more brittle.
Destruction Test
- Data was collected using a Gardner Variable Height Tester.
- Flex strength ASTM D-790.
- Flex Modulus ASTM D-790.reater stiffness allows higher negative pressure capability at equal weights.
| Property | Phenolic Duct | Polyester Duct | Interpretation |
| Impact Test (In-LBS) |
88 | 72 | Ability to resist a point impact |
| Flex Strength (PSI) (Normalized) |
58,619 | 66,6676 | Load bearing strength |
| Flex Modulus (KPSI) |
2325 | 1534 | Stiffness |
FRP Ducting – Fire Resistant Phenolic Resin
FRP ducting is manufactured using phenolic resins. One of the main attractions of phenolic materials is its fire performance. The table below shows some typical fire test results for phenolic/glass composites and compares these to polyurethane and polyester.
Fire Properties of Phenolic/Glass Composites Compared with Polyurethane and Polyester
| Property | Phenolic | Polyester | Rigid Polyurethane |
| ASTM D229 – Oxygen Index | 45-55* | 40 | 20-25 |
| ASTM D229 – Rate of burning | Does not ignite | – | – |
| BS 476 PT.7 – Spread of Flame | Class 1 (Zero Spread) | Class 1 | Class 1 – Class 4 |
| Toxicity of combustion products | Very low | Toxic | Toxic |
| Smoke | Virtually NIL | Very high | Very high |
| * Catalyst Dependent |
When phenolic resin ducting is exposed to fire they char on the surface which further protects the underlying layers from the heat source. In extreme conditions when fire does destroy the product only gasses of Carbon, Hydrogen and Oxygen are produced. This in essence means that the phenolic can only break down to form Carbon Dioxide, Water and Carbon Monoxide. These gasses will result from any form of combustion. A most significant factor is also the very low levels of visible smoke produced. See test results.
Phenolam Laminate Test Results
| Test – Flammability | ASTM Test | Results | |
| NBS Smoke Chamber | E-622 | ||
| D16 | >5 min. | ||
| Dmax | 42 | ||
| Radiant Panel Test | E-162 | 6.7 | |
| Tunnel Test | E-84 | ||
| FS1 | 19 | ||
| Smoke | 12 | ||
| Limiting Oxygen Index | D2863 | 67 | |
| Thermal | |||
| Heat Deflection @ 264 psi | D-648 | >570°F | |
| Linear Thermal Expansion | 2.93 x 10.5 m/in. °F | ||
| Specific Heat @ 50°C | 0.3 cal/ g°F | ||
The physical properties of phenolic fiber reinforced composites are retained to at least 200°C at which temperature other matrix resins have generally degraded substantially. The inherent fire properties of phenolic resins composites are excellent having the highest fire rating in all test methods, extremely low smoke emission and virtually no toxic combustion products. E.M.R. Flame Certificate Number 395.
ROUND, OVAL AND TAPERED FRP DUCTING
Round FRP Ducting
Round filament wound ducting is manufactured in a technically advanced process of bonding phenolic resin and fiberglass strands. Exceptionally smooth inner surface guarantees the lowest friction factor and highest volume of air. Due to its round shape and the outstanding strength Norvent Rigid Round Ducting withstands high positive and negative pressure and resists impacts caused by moving equipment, flying rocks and rough handling. Standard sizes range from 8” to 72” diameter. Standard lengths are 10’ and 20’ (homogeneous, no splice).
Oval FRP Ducting
Oval filament wound ducting is the most efficient way to handle today’s high air requirements in mine ventilation under low space conditions. The special shape and exceptionally smooth inner surface guarantees the lowest friction and highest volume of air. Oval FRP Ducting can be used for both negative and positive pressure ventilation systems. Standard sizes available from 20” equivalent (11 x 30) to 48” equivalent (36 x 62). Standard lengths are 10’ and 20’ (homogeneous, no splice). Fan adapters and fittings are also available.
Tapered FRP Ducting
FRP Tapered Pipe is tapered in shape, allowing sections of ventilation duct to be “stacked” for transportation increasing the number of units per load and reducing shipping costs by a considerable amount. The design improvement has no impact on aerodynamic performance thereby maintaining the best K factor for rigid ventilation duct on the market. Available in limited sizes.
FRP Fittings & Accessories
Special sizes, lengths and wall thickness available on request.
Fittings for all applications are fabricated from flame retardant, corrosion resistant material.
- Elbows
- Tees.
- Wyes – Lateral, Symmetrical and Pant Style.
- All Wyes are available with 1 or 2 dampers.
- Reducers and transition pieces.
- Fan Adapters.
- Bell & Spigot Connections.
- Flanges also available
SUSPENSION HANGERS (STRAPS)
Suspension Hangers (straps) are an inexpensive way to eliminate costly chain or rope and damage to ducting. They are strong and durable and can be suspended from one common hook or from 2 to limit swaying. The Suspension Hangers (straps) can be manufactured to fit any size of round or oval ducting.