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Nitrile Rubber Pipe Insulation: Overview and Brand Highlights


Nitrile rubber is a closed-cell elastomeric foam that combines thermal efficiency, moisture resistance and flexibility. Its built-in vapour barrier stops condensation at the source, while its low thermal conductivity minimises heat loss on hot lines and prevents freezing on chilled services.


Why Choose Nitrile Rubber?

  • Service temperature range from well below freezing up to around +110 °C
  • Closed-cell structure for outstanding moisture and vapour resistance
  • Low thermal conductivity (as low as 0.033 W/(m·K))
  • Self-extinguishing behaviour with Euroclass B fire rating and no flaming droplets
  • Flexible material that adapts easily to bends and fittings


ArmaFlex EVO


ArmaFlex EVO is Armacell’s next-generation Class O nitrile rubber insulation, engineered for both thermal performance and hygiene-sensitive environments.

Key features:

  • Flexible elastomeric foam with improved fire-retardant properties and low smoke generation
  • Closed-cell insulation structure with built-in Microban® antimicrobial protection
  • Self-seal adhesive slit for rapid, tape-free installation
  • Ideal for HVAC, refrigeration and process equipment applications

Typical applications:

  • Chilled-water and refrigeration piping with stringent condensation control needs
  • Commercial HVAC in healthcare, hospitality and food-service sites
  • OEM equipment and clean-room piping

 

K-Flex ST


K-Flex ST is a versatile, pre-split nitrile rubber insulation featuring Insul-Lock® pressure-sensitive closure.

Key features:

  • Service temperature from –165 °C to +110 °C
  • Low thermal conductivity down to 0.033 W/(m·K) at 0 °C
  • Euroclass B-s2,d0 fire performance and pH-neutral composition to prevent corrosion under insulation
  • Resistant to oils, chemicals and microbial growth for long-term reliability

Typical applications:

  • Industrial and process piping requiring wide temperature tolerance
  • Refrigeration and cold-storage facilities down to sub-zero temperatures
  • Plumbing and heating installations where a robust vapour barrier and easy installation are priorities


Installation Best Practices


  • Measure the pipe’s outside diameter precisely before ordering insulation.
  • For tubes, align and press the self-seal slit edges firmly together.
  • Use matching pre-moulded fittings for bends, valves and flanges.
  • Protect outdoor runs with UV-resistant cladding or paint.

By selecting nitrile rubber products such as ArmaFlex EVO or K-Flex ST, you’ll achieve optimal energy savings, effective condensation control and long-term pipe-work protection. Whether your project demands antimicrobial performance or extreme low-temperature resilience, both brands offer reliable solutions.


Visit our Complete Guide to Pipe Insulation to Learn More about the different types of product we have on offer