Key Features
- Exceptional Corrosion Resistance: Inert fiberglass/polymer construction resists acids, alkalis, solvents and salts that quickly damage steel ducts.
- High Strength-to-Weight: Filament-wound GRP is very strong yet lighter than steel, making it easier to handle and support.
- Smooth, Non‑conductive Interior: Seamless resin-rich lining minimizes friction losses and deposit buildup. The non-metallic surface reduces maintenance and prevents galvanic corrosion.
- Customizable Fabrication: Available in a full range of diameters (small to >3 m) and shapes (round, rectangular, pipe, fittings). Can be molded with additional insulation or fire-retardant layers as needed.
- Vacuum and Pressure Ratings: Designed to handle full vacuum up to moderate pressures (±5–10 psi; ~±0.3–0.7 bar), suitable for most exhaust and vent applications.
- Thermal Performance: Depending on resin, standard FRP ducts handle from –40 °C up to ~80–120 °C. Specialty dual-layer systems extend temperature ranges.
Benefits
- Long Service Life & Low Maintenance: GRP ducts do not rust or pit and maintain corrosion resistance over decades.
- Cost Savings: Lightweight ducts reduce installation labor and support costs; smooth interiors lower fan energy use and cleaning needs. Over time, FRP ducts incur lower lifecycle cost than metal or concrete systems.
- Complete Corrosion Barrier: Unlike ductwork with a separate liner, the composite bond in GRP ducting prevents lining delamination and internal corrosion.
- Safety and Compliance: Many GRP duct systems meet fire-safety (UL/FM) and environmental standards (low emissions of smoke/halogen).
- Versatile Installation: FRP ducts can be buried, installed outdoors in freezing climates, or used underground without loss of integrity.
Applications
- Chemical & Petrochemical Plants: Acid and alkali fume exhaust, scrubber ducts, catalyst venting.
- Metal Finishing & Plating: Corrosive acid mist and gas removal (e.g. HCl, H₂SO₄) in plating baths, pickling lines, anodizing.
- Wastewater Treatment: Odor control and aeration ducts handling hydrogen sulfide, chlorine, ammonia.
- Power & Utility: Flue gas desulfurization ducting, coal/gas exhaust, utility stack liners.
- Semiconductor & Pharma: High-purity exhaust (HF, HCl, acids, solvents) with FRP’s clean, inert surfaces.
- Marine & Underground: Ventilation for ship compartments or tunnels exposed to salt spray or sewage gases.
- HVAC in Corrosive Environments: Fume hoods, cleanroom HVAC, chemical plant air handling and underground ducts.
(For example, FRP ducts are explicitly specified in ASTM D3982 for corrosive-fume applications, and SMACNA’s FRP Duct Manual provides design guidance. These ducts are used “in many industrial, water, wastewater…applications where corrosion is a problem,” and “will not corrode” like metal ducts. Manufacturers also custom-make GRP exhaust stacks and scrubbers with thermoplastic liners.)
Technical Specifications (Typical)
- Construction: Glass-fiber filament-wound or hand-layup; vinyl ester/polyester resin matrix; optional interior thermoplastic liner.
- Size Range: Diameters from ~50 mm up to 1200 mm (and larger) in standard lengths. Rectangular ducts also available.
- Pressure Rating: Full vacuum to ~150 psi (10 bar) for smaller ducts (1½″–12″); ~100 psi (7 bar) up to 24″.
- Temperature Range: Depends on resin; typical vinyl ester FRP is rated to ~80–95 °C continuously. Double-wall insulated systems available.
- Standards: Designed per ASTM D3982 (contact-mold FRP duct), ASME RTP-1, SMACNA FRP, etc. Optional UL/FM 4910 fire rating.
Unique Selling Points (USPs)
- 360° Corrosion Protection: No welds or seams means interior lining bonded to structure, eliminating gap corrosion points.
- Lightweight Strength: Up to 50–75% lighter than steel, yet rigid under pressure/vacuum; easier to install without heavy equipment.
- Smooth, Non-Wetted Surface: Eliminates buildup and reduces fouling, ensuring consistent airflow and purity (critical in semiconductor or high-purity systems).
- Custom Solutions: Can combine with insulation, dampers, clean-in-place ports, or special end fittings at the factory.
- Broad Chemical Compatibility: With appropriate thermoplastic liners, the same FRP structure can handle everything from chlorine to hydrofluoric acid.
- 1. PVC + FRP Ducting System
- 2. CPVC + FRP Ducting System
- 3. PVDF + FRP Ducting System
- 4. PFA + FRP Ducting System
- 5. PEEK + FRP Ducting System
- 6. PPR + FRP Ducting System
- 7. PPH + FRP Ducting System
PVC + FRP Ducting System
The PVC+FRP ducting system is a dual-layer composite where a virgin PVC liner is bonded inside an FRP (fiberglass-reinforced polyester or vinyl ester) shell. This combination provides a low-cost yet durable ducting solution. The PVC liner is chemically inert to a broad range of mineral acids, alkalis, salts and organics, while the FRP structure gives mechanical strength and exterior corrosion resistance. PVC/FRP ducts are smooth and seamless, preventing trap of corrosive condensate between layers. They are ideal for many general corrosive fume and airflow applications at moderate temperatures (up to about 77 °C).
Key Features
- Virgin PVC Liner: 100% chemical-grade PVC, seamless to ~6–10″ diameter, highly inert to most acids, alkalis, salt solutions and organic solvents.
- Bonded Dual-Layer: Unique bonding layer chemically fuses PVC to FRP, eliminating delamination and condensation issues that plague lined steel pipes.
- Smooth Interior Surface: Minimizes friction, inhibits deposit buildup, and reduces pressure drop.
- Pressure & Vacuum Capability: Rated for full vacuum up to ~150 psi (per RPS spec).
- Cold-Climate Robustness: PVC liner handles sub-zero temperatures; FRP shell remains resilient.
Benefits
- Cost-Effective Corrosion Barrier: Provides excellent resistance to acids (e.g. sulfuric, nitric) and alkalis at lower cost than exotic plastics.
- Low Maintenance: Inert PVC liner requires no coatings and resists abrasion/corrosion from flow.
- Chemical Inertness: Handles most aqueous chemical fumes without leaching or degradation.
- Long Lifecycle: Combined FRP/PVC construction extends life beyond rubber-lined steel or single-material duct.
Applications
- Acid and alkali ventilation (e.g. hydrochloric, phosphoric, nitric acid fumes).
- Chemical processing vents, loading stations, scrubber ducts.
- Saltwater and chlorine-enriched environments (swimming pools, desalination plants).
- HVAC and exhaust in wastewater treatment, plating shops, labs (where moderate heat and inorganic chemicals occur).
Technical Specifications
- Material: Virgin polyvinyl chloride (PVC) liner bonded to FRP shell.
- Temp. Rating: 0 °F to 170 °F (–18 °C to +77 °C).
- Pressure Rating: Full vacuum to ~150 psi (1½″–12″), to ~100 psi (14″–24″).
- Diameter: Typically seamless to 6–10″ (150–250 mm); larger sizes by field joint or spiral-wind.
- Standards: Meets ASTM D2992 (PVC FRP dual laminate) and custom engineering specs.
Unique Selling Points (USPs)
- Broad Chemical Compatibility: Inexpensive solution for acids, alkalis, salts – many duct systems use PVC liners for these media.
- Easy Fabrication: PVC is easy to bond and weld on-site if necessary.
- Steam/Heat Cleaning: PVC can tolerate periodic high-temp cleaning (up to its temperature limit) better than some alternatives.
- Service in Ambient to Warm Conditions: Ideal for tropical or heated plant environments where corrosion is a threat.
CPVC + FRP Ducting System
The CPVC+FRP duct system uses a chlorinated PVC (CPVC) liner, which offers higher temperature and acid resistance than standard PVC, bonded inside an FRP shell. Like PVC/FRP, the CPVC liner is seamless and chemically inert to many process chemicals, but its chlorine content allows continuous service up to ~93 °C and better durability in hot, acidic streams. The FRP exterior provides structural strength and corrosion resistance. This system is well-suited for hotter, more demanding chemical exhaust than plain PVC ducts.
Key Features
- Virgin CPVC Liner: Handles higher temperatures (up to ~200 °F) and stronger chemicals (e.g. hydrochloric or sulfuric acids).
- Bonded Liner: Chemical bond between CPVC and FRP prevents separation and weeping under thermal cycles.
- Smooth Fume Barrier: Provides clean, glassy surface with no internal scale.
- Moderate Pressure Use: Full vacuum to ~150 psi (small diameters).
- Long-Term Durability: Resists internal corrosion, eliminating the need for sacrificial anodes or coatings.
Benefits
- Higher Temp Capability: For applications where PVC would soften, CPVC extends temperature range by ~15–20 °C.
- Superior Acid Resistance: Excellent for strong inorganic acids and hot water/steam cleaning.
- Reduced Downtime: Even in warm chemical plants, CPVC/FRP ducts last far longer than steel or concrete.
- Clean Operations: Ideal for corrosive fume capture in labs, since CPVC is FDA/USP safe for many solvents.
Applications
- Fume exhaust from hot chemical tanks, reactors and scrubbers (e.g. hot HCl, H₂SO₄ fumes).
- Chemical pump ventilation and sample hoods in chemical processing.
- High-temperature wastewater venting and chemical feed systems.
Technical Specifications
- Material: Virgin chlorinated polyvinyl chloride (CPVC) liner, seamless to ~6″–10″.
- Temp. Rating: 0 °F to 200 °F (–18 °C to +93 °C).
- Pressure Rating: Full vacuum to ~150 psi for 1½″–12″.
- Chemical Resistance: Superior to PVC against acids (HCl, H₂SO₄), alkalis, organic solvents.
- Jointing: FRP flange joints, or CPVC fusion bonding for pipes ≤10″.
Unique Selling Points (USPs)
- High-Heat Chemical Use: Fills gap between PVC and exotic fluoropolymers – for example, venting 80–90 °C acid vapors that PVC cannot handle.
- Cost-Effective Upgrade: Achieves near-PVDF performance on many streams at lower cost.
- Seamless Transitions: CPVC/FRP systems easily connect to existing PVC or FRP ductwork, enabling upgrades.
PVDF + FRP Ducting System
The PVDF+FRP system incorporates a polyvinylidene fluoride (PVDF) liner bonded inside an FRP casing. PVDF is a highly fluorinated resin with exceptional chemical resistance, especially to halogenated compounds and strong solvents. In dual-laminate form, PVDF/FRP ducts remain inert to a broad spectrum of aggressive chemicals. They are often used in high-purity or specialty chemical exhaust. The standard PVDF liners (often natural/undyed for purity) operate continuously up to ~104 °C.
Key Features
- PVDF Liner: Seamless PVDF up to ~12″ diameter, inert to nearly all acids, bases and organics. Handles chlorinated and brominated chemicals, oxidizers and most solvents.
- High Purity: Natural PVDF is FDA- and USP-compliant; no plasticizers or fillers.
- Enhanced Bonding: Special primer bond prevents liner delamination even under thermal stress.
- Wide Temp Range: –20 °C to 220 °F (–5 °C to +104 °C); short-term excursion to ~120 °C possible.
Benefits
- Ultra-High Chemical Inertness: Handles chemicals that attack most plastics and metals, including chlorinated solvents, strong oxidants and ultrapure process streams.
- Superior Durability: Outer FRP protects the PVDF liner and allows long, unbroken pipe runs with minimal joints.
- Purity and Cleanability: Ideal for pharmaceutical, electronics or semiconductor exhaust where any contamination is unacceptable.
- Thermal Endurance: More heat resistant than PVC or PP; suitable for hot solvent fumes.
Applications
- Venting of chlorinated solvents and halogen gases (e.g. etch exhaust in semiconductor fabs).
- Acid and oxidizer exhaust (e.g. nitric acid, perchlorates, bleach line ventilation).
- High-purity chemical processing and ultrapure water exhaust.
Technical Specifications
- Material: 100% PVDF fluoropolymer liner (natural color), seamless to ~12″.
- Temp. Rating: –5 °F to 220 °F (–20 °C to +104 °C).
- Pressure Rating: Full vacuum to ~150 psi (for smaller sizes).
- Pressure Drop: Very low at given flow due to ultra-smooth PVDF surface.
- Standards: Complies with ASTM D6780 (FRP with PVDF liner) where applicable.
Unique Selling Points (USPs)
- Halogen & Solvent Service: Where even CPVC or PVC can fail (e.g. hot chlorine or bromine vapors), PVDF/FRP stands up.
- FDA-Safe Option: Natural PVDF variant for food/pharma gas handling.
- Broad Spectrum: “Best-of-both-worlds” – much of the chemical resistance of Teflon® at lower cost, combined with FRP strength.
- Lower Friction: Very smooth, reducing fan energy and preventing particle accumulation.
PFA + FRP Ducting System
The PFA+FRP duct system features a perfluoroalkoxy (PFA) Teflon®-type liner inside an FRP shell. PFA is a fluoropolymer like PTFE but can be molded into a seamless liner. The PFA liner confers virtually universal chemical resistance – it will withstand all common acids (including HF!), oxidizers, solvents, caustics and organic chemicals. In dual-laminate FRP, it provides the ultimate corrosion barrier for the most aggressive exhausts. The standard PFA system operates up to ~220 °F (104 °C) under continuous use.
Key Features
- PFA Liner: Seamless up to ~10″ diameter. Unmatched inertness to acids (HF, aqua regia), strong caustics, bleaching agents, solvents, phenols and more.
- Heat & Chemical Stability: No loss of mechanical properties in boiling or high-concentration chemicals.
- Bond Integrity: FRP shell bonded to PFA eliminates liner separation even with temperature swings.
- Smooth PTFE Surface: Ultra-low friction, non-stick interior – ideal for particulate or polymerizing gases.
Benefits
- Universal Chemical Compatibility: The PFA/FRP system can handle streams that destroy most other materials, from hydrofluoric acid to strong oxidizers.
- Safety in Harshest Conditions: Even perchloric acid or mixed-acid fumes can be safely ducted.
- Minimal Fouling: Organic vapors that polymerize or condense will not adhere to the PFA surface, preventing line clogging.
- Long-Term Reliability: The combination of PFA liner and FRP casing yields decades of life where metals would require constant upkeep.
Applications
- Semiconductor wafer processing exhaust (HF, HCl, HNO₃, solvents).
- Chemical plants handling hydrofluoric acid, aqua regia, or strong oxidizers in process vents.
- High-temperature corrosive stacks (e.g. mixed-acid distillation vents).
Technical Specifications
- Material: Perfluoroalkoxy (PFA) fluoropolymer liner, seamless to ~10″.
- Temp. Rating: –5 °F to 220 °F (–20 °C to +104 °C) (continuous).
- Pressure Rating: Full vacuum to ~150 psi for 1½″–12″.
- Chemical Resistance: Better than PVDF – suitable for all acids (including HF, aqua regia), caustics, solvents, and bleaching agents.
- Ease of Cleaning: Can be steam or chemical-cleaned without damage.
Unique Selling Points (USPs)
- Ultimate Corrosion Barrier: Handles virtually any chemical stream (no need to guess, PFA is safe where others fail).
- High-Purity Exhaust: Ideal for industries requiring the cleanest duct surface (e.g. pharmaceutical solvent recovery).
- Extreme Service: The gold standard for V.O.C. and fume control when regulatory or safety limits are tight.
- Minimal Leakage Risk: Seamless PFA liner eliminates porosity or microcracks common in PTFE tapes or coatings.
PEEK + FRP Ducting System
PEEK+FRP combines an inner PEEK (polyether ether ketone) lining with a fiberglass composite exterior. PEEK is a premium high-performance thermoplastic noted for its exceptional thermal stability and chemical resistance. In duct form, a PEEK liner (seamless up to ~6″) can withstand continuous temperatures up to ~150 °C and resists degradation by most chemicals (strong acids, bases, hydrocarbons, oxidizers, etc.). The FRP shell provides structural support and high strength, making PEEK/FRP ducts ideal for extreme exhaust environments where metal or common plastics cannot endure.
Key Features
- PEEK Liner: Unfilled PEEK polymer, seamless to moderate diameter, inherently inert to nearly all chemicals.
- High-Temp Performance: Maintains tensile strength after thousands of hours at ~150 °C. Can handle short-term excursions up to 260 °C (PEEK’s melting point) in certain designs.
- Robust Construction: FRP shell can be engineered with high-temp vinyl ester resin to complement PEEK’s capabilities.
- Low Smoke/Emission: PEEK is halogen-free and emits very low smoke or toxic gas if ever overheated.
Benefits
- Extreme Durability: Far outlasts even PVDF/PFA in high-temperature or high-purity applications.
- Wear and Fatigue Resistance: Excellent for dynamic or abrasive flows (PEEK is used in aerospace and offshore for this reason).
- Design Flexibility: PEEK ducts can be custom-formed (bends, flanges) and bent on-site if needed due to polymer’s toughness.
Applications
- High-temperature chemical venting (e.g. high-pressure steam with contaminants).
- Aerospace and power-generation exhaust (fuel cell stacks, turbine bleed lines) where heat and purity are critical.
- Semiconductor wet bench exhaust and CMP scrub exhaust.
- Any exhaust where plastic-coated steel is used today but a superior polymer is desired.
Technical Specifications
- Material: Unreinforced PEEK liner (seamless smaller diameters).
- Temp. Rating: –60 °C to +150 °C (no loss in strength after 5,000 h at 150 °C). Short-term maximum ~260 °C.
- Pressure Rating: Design per project; FRP structure typically rated similar to other dual-lam pipes (up to ~150 psi).
- Chemical Resistance: Excellent to almost all chemical media (strong acids, bases, solvents, oils) and hydrolytically stable.
- Standards: Not yet standardized in duct codes; engineered per application requirements.
Unique Selling Points (USPs)
- Ultra-High Performance: The highest temperature and mechanical strength liner available in a composite duct.
- Semiconductor-Grade Purity: Used where even trace contamination or outgassing from other plastics is unacceptable.
- Long-Term Reliability: Extremely low creep and wear; resists stress-corrosion cracking.
- Lightweight Alternative to Metal: Combines metal-like service (high temp, pressure) with polymer corrosion resistance.
PPR + FRP Ducting System
The PPR+FRP ducting system uses a polypropylene random-copolymer (PPR) liner inside an FRP shell. PPR is a tough, impact-resistant plastic commonly used in plumbing and HVAC. In duct form, PPR offers excellent resistance to acids, alkalis, alcohols and water at temperatures up to ~93 °C. When bonded in a dual-laminate FRP system, it creates a durable duct for chemical exhaust where some heat is present but high-end specialty liners are not needed. PPR/FRP ducts combine the low cost of polypropylene with the strength of fiberglass reinforcement.
Key Features
- Virgin PPR Liner: Chemically inert to a wide range of inorganic chemicals (strong acids/bases, salt solutions). Often pigmented blue or green for identification.
- Flexible Resilience: PPR’s material toughness gives ducting good impact and thermal shock resistance.
- Pressure Tolerance: Rated for moderate pressures (up to ~150 psi, small sizes) and vacuum.
- Weldable Joints: Sections up to ~8″–10″ may be butt-fused on site for leak-free seams.
Benefits
- Versatility: Handles many common chemical fumes and vapors in industry (e.g. alkaline vapors, salt spray, alcohol fumes) without degradation.
- Temperature Endurance: Better than PVC; suitable for warm water and mild steam exhaust (up to ~80–90 °C).
- Affordable Solution: Polypropylene is cost-effective compared to PVDF or PFA for non-extreme media.
- Durability: Resists fatigue and creep in service due to its isotactic crystalline structure.
Applications
- Ventilation of moderate-temperature chemical processes (e.g. caustic scrubbers, solvent vents).
- HVAC/chilled-water ducting in corrosive environments (e.g. cooling tower vent lines, pool/spa chemical rooms).
- Plating shop acid-neutralizing ventilation (where strong acids/alkalis are both present).
Technical Specifications
- Material: Virgin polypropylene (PPR) liner, seamless to ~10″ diameter.
- Temp. Rating: 15 °F to 200 °F (–10 °C to +93 °C) (continuous).
- Pressure Rating: Full vacuum to ~150 psi (for 1½″–12″).
- Corrosion Resistance: Excellent versus mineral acids, alkalis, salt solutions.
- Standards: Meets ASTM D3261/D2657 for PP piping; dual-laminate per customer spec.
Unique Selling Points (USPs)
- Hot/Cold Water Systems: PPR/FRP is ideal for HVAC chilled water or process water ducts that may carry some contaminants.
- Toughness: More impact- and fracture-resistant than PVC/CPVC, reducing damage during installation or handling.
- Chemical Flexibility: Compatible with both strong acids and bases, unlike some PVC-based ducts.
- High-Purity Option: Natural (unpigmented) PPR liners are available for potable-water or ultra-clean applications.
PPH + FRP Ducting System
The PPH+FRP ducting system uses a polypropylene homopolymer (PPH) liner combined with an FRP structure. PPH differs from PPR in its higher crystallinity and chemical purity (no elastomeric modifiers), making it very resistant to aggressive chemicals. PPH/FRP ducts are designed for heavy-duty corrosive service at temperatures up to around 80–95 °C. The seamless PPH liner inside the FRP shell provides a virtually inert barrier to most acids, alkalis and solvents. This system is chosen when chemical resistance is paramount and slight sacrifice in impact toughness (vs. PPR) is acceptable.
Key Features
- PPH Liner: High-purity polypropylene with excellent chemical stability.
- Corrosion Barrier: Withstands even concentrated mineral acids and solvents (similar to PP but at its best).
- Thermal Limits: Continuous service typically up to ~90 °C, depending on resin grade.
- Bonded Construction: Ensures full encapsulation of liner, eliminating gaps that trap moisture.
Benefits
- Enhanced Chemical Resistance: Slightly better resistance to high pH and organic solvents than PPR. Suitable for strong caustic or acid fumes at moderate heat.
- Lightweight Strength: As with all FRP, weight is far less than metal duct of equal diameter.
- Cost-Effective Toughness: While PPH is not as impact-flexible as PPR, its strength under chemicals makes it reliable in aggressive plant environments.
Applications
- Corrosive exhaust in chemical plants (e.g. venting concentrated acids like HNO₃, HCl at moderate temperature).
- Process air in pulp/paper mills (bleach plant gases) or chemical processing.
- Caustic fume removal in electroplating or alkali production.
Technical Specifications
- Material: Virgin polypropylene homopolymer (PPH) liner, seamless up to ~8″–10″.
- Temp. Rating: Approximately –10 °C to +90 °C (depending on batch).
- Pressure Rating: Similar to PPR: vacuum to ~150 psi (small diameters).
- Chemical Resistance: Excellent to concentrated acids and bases; similar to PP.
- Standards: Proprietary; follows FRP piping design rules and material specs.
Unique Selling Points (USPs)
- Extra Resilient to Caustics: Preferred when handling high-concentration caustic fumes that could stress a PPR liner.
- Pure Polypropylene: PPH is used where any elastomer content (in PPR) might be a liability (e.g. sanitizable ducts).
- Dual-Laminate Upgrade: Provides a simple way to upgrade standard PP duct to full FRP-strength for long runs or buried duct.