EPDM vs Nitrile Rubber: The Short Answer

Aeroflex and ArmaFlex are both flexible closed-cell elastomeric foam insulation, used on the same air conditioning, refrigeration, chilled water and plumbing pipes. The main difference is the rubber. Aeroflex is made from EPDM. Standard ArmaFlex products are based on nitrile (NBR) synthetic rubber.

Thermal performance is similar. The practical differences are UV resistance, maximum temperature and what you need to do when the insulation is installed outdoors.

Aeroflex vs ArmaFlex at a Glance

Aeroflex Standard (EPDM)

  • Material: EPDM closed-cell elastomer
  • Operating temperature: -57°C to +125°C (HT grade to 150°C)
  • Thermal conductivity: 0.039 W/m·K or better at +40°C
  • UV and weather: excellent UV, weather and ozone resistance
  • Fire: AS 1530.3 indices 0 / 0 / 0 / 3

ArmaFlex AC Class O (nitrile)

  • Material: closed-cell elastomeric foam based on synthetic (nitrile) rubber
  • Operating temperature: -50°C to +110°C
  • Thermal conductivity: 0.040 W/m·K at +40°C
  • UV and weather: UV protection is necessary outdoors (paint or cladding within 3 days)
  • Fire: BS 476 Class 0, ASTM E84 25/50

ArmaFlex figures from Armacell’s published ArmaFlex AC Class O technical data sheet. Check the current data sheet for the product you are comparing.

Which Should You Choose?

Outdoor pipe runs

Air conditioning lines, solar hot water and exposed plumbing. EPDM handles sun and weather without paint, which saves a step on install and maintenance.

Hot water & solar

For hotter lines, Aeroflex Standard is rated to 125°C and Aeroflex HT to 150°C, above the 110°C maximum published for ArmaFlex AC Class O.

Indoor chilled & refrigeration

Both perform well indoors. Choose on project specification, fire test requirements, size range and availability.

Shop Aeroflex pipe insulation
Shop Aeroflex HT solar insulation
Shop Aeroflex insulation sheets

Aeroflex vs ArmaFlex FAQs

No. They are different brands of closed-cell elastomeric insulation. Aeroflex is EPDM rubber; standard ArmaFlex is based on nitrile synthetic rubber. They are used for the same jobs and come in similar tube and sheet sizes.

In most cases, yes, provided the Aeroflex product meets the project specification for wall thickness, temperature and fire performance. Check the specification before substituting on a commercial job.

Armacell’s data sheet for ArmaFlex AC Class O says UV protection is necessary outdoors, using paint or a covering within 3 days of installation. Aeroflex EPDM has excellent UV resistance without paint.

Yes. Aeroflex is tested to AS 1530.3 with indices of 0 / 0 / 0 / 3 (Ignitability, Spread of Flame, Heat Evolved, Smoke Developed). Read in conjunction with the Building Code of Australia.

ArmaFlex and Armacell are trademarks of Armacell. Australian Sun Energy is an authorised Aeroflex distributor.