NBR Duct Gasket Tape

What is a Duct Gasket?

A duct gasket is a roll-type material made from foam rubber (commonly NBR or EPDM) with high elasticity, thermal insulation, and soundproofing properties. The outer surface is pre-coated with adhesive, making installation much faster and simpler compared to traditional sealing methods.

Gaskets come in various thicknesses and widths, typically 5–10 mm thick, 20–30 mm wide, and 10 m per roll. They are commonly used to seal joints, gaps, or act as cushioning between contact surfaces in duct systems.

Why Use Gaskets in HVAC Systems?

Using duct gaskets not only simplifies installation but also helps:

• Prevent cold air leakage and energy loss

• Improve thermal insulation and reduce operating costs

• Reduce vibration and noise, improving indoor comfort

• Provide moisture and mold resistance, extending system lifespan

• Meet airtightness standards in industrial facilities, malls, and hospitals

According to LEED standards and modern HVAC practices, sealing duct joints with gaskets is essential to ensure energy efficiency and indoor air quality.

Structure and Materials of NBR Duct Gaskets

Cross-linked NBR Foam Rubber

NBR duct gaskets are made from nitrile rubber foam, a synthetic material with excellent oil and chemical resistance. The foam structure makes it lightweight, elastic, and easily compressible—ideal for sealing areas requiring airtightness or subject to slight vibration.

This rubber is processed using physical cross-linking, not traditional chemical bonding, providing superior thermal stability and durability even in harsh temperature or humid environments.

Closed-Cell Structure – The Key Factor

Unlike ordinary foam materials, NBR gasket foam has a fully closed-cell structure, which:

• Completely blocks moisture and air penetration

• Enhances thermal insulation and soundproofing

• Prevents mold and bacterial growth

Therefore, it is preferred in moisture-prone environments such as cold rooms, basement ducts, and industrial HVAC systems.

Advantages of NBR Duct Gaskets

Heat Resistance, Soundproofing, and Thermal Insulation

NBR rubber operates within -50°C to 110°C, suitable for both residential and industrial HVAC systems.

• Excellent insulation: Thermal conductivity only 0.034 W/m·K

• Effective soundproofing: Closed-cell structure absorbs sound waves

• Chemical resistance: Resists oil, grease, solvents, and moisture

Superior Durability and Airtightness

Thanks to the closed-cell structure and specialized adhesive, NBR gaskets adhere well to metal and plastic surfaces. Compression strength ≥ 3–6 H ensures airtight sealing even under repeated pressure.

• Density 85 kg/m³ provides long-term elasticity without deformation

• Meets ASTM D6435 and UL 94 fire safety standards

Convenience in Installation and Maintenance

With pre-applied adhesive, NBR gaskets:

• Reduce installation time by up to 50%

• Require no additional glue, staples, or tape

• Provide clean installation without damaging surfaces

During maintenance, old gasket can be easily removed and replaced without affecting the duct system.

Practical Applications

HVAC, Ventilation, and AHU Systems

• Seal flexible-to-rigid duct joints in buildings

• Cushion between flanges and steel frames to prevent air leakage

• Reduce vibration in AHU and FCU units

• Seal technical gaps in basements and cold rooms

Doors, Windows, and Cleanrooms

• Soundproof and dust-proof door/window frames

• Cushion between glass and aluminum or stainless frames

• Seal floor-to-ceiling gaps in cleanrooms and cold storage

Due to high elasticity and adhesion, NBR gaskets can be reused in systems requiring flexible disassembly.

How to Select and Install Duct Gaskets Properly

Choosing the Right Size and Compression

Selection depends on installation location, duct size, and insulation requirements:

• Thickness: 5 mm (common for rectangular duct joints); 6–10 mm for larger gaps/flanges

• Width: 25–30 mm for standard ducts, 40 mm for larger ducts

• Density: ≥ 85 kg/m³ for long-term elasticity

• Adhesive: Must bond well to galvanized steel surfaces

Note: For humid areas (basements, AHU), choose fully waterproof and fire-rated products.

Proper Installation Steps

1. Clean surface: Remove dust, oil, rust using cloth or alcohol

2. Measure & cut: Cut gasket accurately with a sharp blade

3. Peel adhesive backing: Slowly remove protective film, avoid dust contamination

4. Apply gasket: Press evenly to avoid bubbles or gaps

5. Compress joint: Ensure proper sealing when assembling duct sections

Tip: After installation, check corners manually. If slight lifting occurs, reinforce with aluminum HVAC tape.

Tips to Improve Performance and Lifespan

• Do not apply on wet surfaces

• Do not reuse peeled gasket

• Store in cool, dry place away from sunlight

• Replace every 3–5 years depending on environment

Conclusion

NBR duct gaskets are not just accessories but a strategic solution for stable, efficient, and safe HVAC operation. With closed-cell moisture resistance, sound insulation, and fire safety, they play an essential role in modern technical systems. Proper selection, installation, and maintenance will maximize long-term performance and durability.