Flexible elastomeric pipe insulation has been available in the United States since the early 1950s. It is also known as closed cell elastomeric insulation, cellular foam insulation, closed cell elastomeric foam insulation, rubber, unicellular foam insulation, refrigeration pipe insulation, hvac pipe insulation, ac return line insulation, plumbing pipe insulation, uv resistant refrigerant line insulation, refrigerant pipe insulation, hvac refrigerant line insulation, plumbing equipment insulation, ac refrigerant line pipe insulation, and epdm insulation.
Essentially, flexible elastomeric pipe insulation is a synthetic rubber composed of closed cell structure available in factory-made tubes, sheets or rolls. The outer edge consists of a smooth surface or “skin” which serves as a built-in vapor retarder. Due to flexible elastomeric pipe insulation’s flexible nature, it is less susceptible to cracks, breakage, and material loss when compared to other types of closed-cell rigid insulation options.
Flexible elastomeric pipe insulation is best known for HVAC, refrigerant, and plumbing piping and equipment because of its exceptional ability to control condensation on cold (below-ambient) mechanical systems. Due to its low water vapor permeability, closed-cell structure, and built-in vapor retarder, flexible elastomeric pipe insulation is an excellent choice to protect piping and equipment from one of the most common problems and owner concerns in the building and construction industry – corrosion under insulation or “CUI”. This is a costly but preventable problem when moisture penetrates the insulation and attacks expensive mechanical systems.
When properly designed, specified, and installed, flexible elastomeric pipe insulation can effectively manage heat gain/loss and condensation control for the life of the mechanical system. Unlike open-cell fibrous insulation types, flexible elastomeric pipe insulation does not lose its thermal efficiency or serve as a food source for mold growth when moisture comes in contact with the insulation.
One of the most important considerations when designing, specifying, and installing flexible elastomeric pipe insulation is the insulation thickness. Factors such as the fluid or gas (line) temperature in the pipe or equipment, pipe type, pipe size, ambient temperature, relative humidity, and whether or not a protective outer jacket will be applied are necessary to calculate the correct insulation thickness. Flexible elastomeric pipe insulation’s low thermal conductivity translates into reduced thickness requirements than other closed-cell rigid insulation types.
U.S. manufacturers of flexible elastomeric pipe insulation offer tubes in “unslit” or “self-seal” formats. Sheets and rolls are also offered with or without a factory-applied pressure-sensitive adhesive (PSA) on one side. Self-seal tubes and sheets/rolls with PSA offers are known to produce labor savings during installation.
Tubes are generally available in “wall thicknesses” of ¼” to 2” and inside diameter (ID) sizes of ¼” to 6” IPS (iron pipe size). Aeroflex offers tube sizes up to 16” IPS. Sheet sizes are typically 3’x4’ and rolls 48” wide with thicknesses ranging from ¼” to 2” to insulate larger pipe sizes.
Flexible elastomeric pipe insulation is appropriate for the following interior and exterior applications:
- HVAC piping
- VRF/VRV (variable refrigerant flow/variable refrigerant volume) pipe insulation
- Refrigerant piping
- Chilled water systems
- Cryogenic piping (down to -320℉)
- Hot and cold domestic water piping (NBR/PVC up to 220℉, EPDM up to 257℉)
- Acoustic attenuation of pipes (lower frequencies)
Regarding direct UV exposure, flexible elastomeric pipe insulation will degrade over time so it should be protected with the manufacturer’s specially-formulated UV coating or field-applied jacketing system. Traditional NBR/PVC (nitrile butadiene rubber/PVC) flexible elastomeric pipe insulation will degrade faster than EPDM flexible elastomeric pipe insulation. EPDM is inherently UV-resistant and will degrade at a slower rate than NBR/PVC. Although not UV-proof, EPDM insulation is the same type of rubber used for industrial and automotive applications.
American manufacturers of flexible elastomeric pipe insulation must comply with ASTM manufacturing standards (ASTM C 534, C 411) and meet critical fire and smoke safety standards such as ASTM E 84 (UL 723), NFPA 90A, and 90B. Insulation that is plenum-rated is a term associated with meeting these fire safety standards which allows engineers to specify flexible elastomeric pipe insulation on pipes and ducts in air plenums. In case you were wondering, a plenum is generally the space ®between a structural ceiling (i.e. roof) and drop ceiling.
Flexible elastomeric pipe insulation is also safe for building occupants because it is fiber-free (no fibers break loose from the insulation), mold-resistant and low-VOC. U.S. manufacturers typically add biocides to their NBR/PVC insulation during manufacturing to manage potential exposure to mold. As an alternative, EPDM flexible elastomeric pipe insulation is naturally microbial-resistant. Most American-made flexible elastomeric pipe insulation is also third-party certified by a nationally-recognized test lab for low chemical emissions (volatile organic compounds or VOC’s).
If you are searching for a proven and safe pipe insulation to save energy, control condensation, meet national/state/local energy and building codes, prevent mold growth and contribute to LEED®-registered projects, look no further than Aeroflex USA’s Aerocel® brand of EPDM flexible elastomeric pipe insulation. To learn more, click here.