Key Features at a Glance

1. Hand-Wrapped Multi-Ply Construction
   Unlike mass-produced molded parts, each rectangular joint is hand-wrapped with multiple layers of high-strength synthetic fabric and tire cord in a bias-ply configuration. This artisan process ensures maximum structural integrity across the entire rectangular profile — including the critical corner zones — delivering a significantly longer service life under constant movement cycling compared to molded alternatives.
2. 100% Leak-Proof Performance
   The integral rubber body and flange design provide a complete gas-tight seal through elastic deformation alone, making it the perfect choice for conveying hazardous flue gases, dust-laden air, and chemically contaminated airstreams. No auxiliary gaskets are required, eliminating the number one source of field leakage in conventional duct connector installations.
3. Superior Acoustic & Vibration Isolation
   The inherent damping properties of high-grade elastomeric compounds significantly outperform metallic bellows in absorbing fan-induced vibrations and reducing high-frequency noise transmission through the ductwork network. This isolation protects sensitive downstream instrumentation and reduces occupational noise levels in plant environments.
4. Zero Reaction Stress on Ductwork
   The exceptionally low spring stiffness of the reinforced rubber bellows ensures that minimal reaction forces are transmitted back to the rigid connected ductwork, protecting your system’s structural anchors, support brackets, and adjacent equipment flanges from fatigue damage caused by thermal cycling and vibration.
5. Corrosion & Weather Resistance
   Formulated to withstand aggressive industrial environments, our rubber compounds resist UV radiation, atmospheric ozone degradation, and a wide range of corrosive chemicals commonly found in desulfurization (FGD), selective catalytic reduction (SCR), and industrial dust removal systems operating in harsh outdoor conditions.
6. Fully Customizable Rectangular & Square Profiles
   Every rectangular duct joint is custom-fabricated to match your exact duct cross-section dimensions. Whether you need a small 200×200mm ventilation connector or a massive 4000×3000mm power plant main duct expansion joint, each unit is manufactured precisely to your specified width × height profile with no standard size limitations.
7. Multi-Dimensional Movement Compensation
   Concurrently accommodates axial compression and extension along the duct axis, lateral shear deflection perpendicular to the flow direction, and angular rotation misalignment between connected duct sections — all within a compact face-to-face length while maintaining low reaction force characteristics.
8. Wide Elastomer Material Selection
   Standard Chlorobutyl liner for heat resistance and gas impermeability. EPDM option for general weather and steam service. FKM (Viton) available for extreme chemical and acid exposure up to +204°C. Outer cover options include durable Neoprene or EPDM compounded specifically for environmental protection.

Key Technical Advantages

• Hand-Wrapped Multi-Ply Construction: Unlike mass-produced molded parts, our rectangular joints are individually hand-wrapped with multiple layers of high-strength synthetic fabric and tire cord reinforcement applied in optimized bias-ply orientations around the entire rectangular perimeter — including the geometrically critical corner zones where stress concentrations would otherwise cause premature failure in molded products. This process ensures maximum structural integrity and delivers a substantially longer service life under constant thermal cycling and continuous movement.
• 100% Leak-Proof Performance: The integral rubber body and vulcanized full-face flange design provide a complete hermetic seal solely through controlled elastic deformation of the joint material itself against the mating duct flange face. This zero-gasket architecture makes it the ideal choice for conveying hazardous flue gases containing SOx/NOx condensates, combustible dust, and chemically contaminated airstreams where even minor leakage is unacceptable from both safety and environmental compliance standpoints.
• Superior Acoustic & Vibration Isolation: The inherent viscoelastic damping properties of high-grade rubber compounds dramatically outperform equivalent metallic bellows assemblies in absorbing fan-induced mechanical vibrations and attenuating high-frequency airborne noise transmission through the ductwork network. This dual-function capability simultaneously protects sensitive downstream instrumentation mounts from fatigue damage while reducing overall plant ambient noise levels.
• Zero Stress on Connected Ductwork: The extremely low spring stiffness characteristic of the multi-ply reinforced rubber bellows construction ensures that minimal reaction forces are transmitted back into the rigid connected ductwork structure during all phases of operation — protecting your system’s fixed anchor points, spring hanger assemblies, support bracket weldments, and adjacent equipment flanges from progressive fatigue damage caused by unrestrained thermal growth and vibration.
• Corrosion & Weather Resistance: All rubber compounds are carefully formulated and tested to withstand aggressive industrial atmospheric environments including intense UV solar radiation, ozone concentration buildup from electrical equipment discharge, acid rain deposition, and direct chemical spray exposure encountered in desulfurization (FGD) scrubber systems, selective catalytic reduction units, baghouse dust collector installations, and outdoor processing plant duct corridors.

Material Customization Options

Technical Specifications

Installation Guidelines for Rectangular Duct Joints

1. Pre-Installation Dimension Verification: Before bolting, confirm that the actual installed face-to-face distance of the connecting duct spools matches the manufactured free-length dimension of the expansion joint within tolerance. Do not use the joint as a duct alignment tool — this will induce permanent pre-stress into the elastomer body and shorten service life.
2. Incremental Star Torque Pattern: Tighten flange bolts using a cross-diagonal star pattern over 3 to 4 sequential tightening stages. Ensure uniform compression distribution across the entire rectangular perimeter flange area, paying extra attention to the four corner bolt zones where stress concentration is highest.
3. Thermal Protection During Welding: If any welding, grinding, or cutting operations occur near the installed rubber joint, fully shield the elastomer body with certified high-temperature welding blankets. Direct contact with molten slag, sparks, or hot metal particles will instantly damage the cross-linked outer cover compound and void warranty coverage.

Typical Applications

Product Tags

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