Nitrile Rubber Tube

Nitrile rubber tube is closed-cell elastomeric foam pipe insulation used on chilled water lines, refrigeration and air-conditioning piping. Its closed-cell structure acts as a built-in vapor barrier, with a water vapor resistance factor above 7000, and its thermal conductivity is 0.033 to 0.040 W/mK at 0°C. It is flexible and supplied in 2 m lengths.

Nitrile rubber tube is rated for -40°C to +105°C, which covers chilled water, refrigerant and air-conditioning lines. For lines colder than -40°C, such as cryogenic service, PUF Pipe Section & Board or Cellular Glass Block & Pipe is used instead; above 105°C, choose a hot insulation such as Rockwool Pipe Section.

Nitrile rubber tube fits pipe sizes from 1/2 to 8 inch NB, in wall thicknesses of 6, 9, 13, 19, 25, 32, 40 and 50 mm. The thickness needed depends on pipe temperature, ambient temperature and humidity; hot, humid climates need thicker walls to keep the outer surface above dew point. The heat-loss calculator on this site helps check surface temperature.

Nitrile rubber tube is poly-bagged and boxed in cartons, and quantities are counted in 2 m pieces for each pipe size and thickness. To order, convert pipe lengths into pieces and list them by NB size and wall thickness. Cartons are light but bulky, so tubes are often combined in one container with Nitrile Rubber Sheet & Roll, Contact Adhesive and tapes.

Use Nitrile Rubber Tube on pipes up to 8 inch NB, where one piece slides over the pipe or is slit and closed around it. Use Nitrile Rubber Sheet & Roll on larger pipes, ducts, tanks, fittings and irregular shapes. Both share the same closed-cell material and temperature range, and many projects use them together.

On new pipes, nitrile rubber tube is slid over the pipe before connection; on existing pipes it is slit lengthwise, fitted and closed with Contact Adhesive. All seams and butt joints must be glued so the vapor barrier stays continuous, because one open joint lets moisture condense under the insulation. Joints can be finished with PVC & Cloth Insulation Tape.

Yes, if it is protected from sunlight. Nitrile rubber tube has good ozone and UV resistance when supplied with a UV-protected outer skin, which should be specified for outdoor lines. Otherwise, outdoor tube is protected with a coating or with Aluminum Cladding Sheet & Coil, which also guards against mechanical damage on rooftops and pipe racks.

Nitrile rubber tube is listed to ASTM C534, the specification for flexible elastomeric cellular insulation in sheet and tubular form, and BS EN 14304 for flexible elastomeric foam products. Its fire rating is Class O / Class 1 to BS 476 Parts 6 and 7. Tell us in your enquiry if you need test certificates and we will confirm what is available.

Nitrile rubber tube is classified under HS code 40091100, tubes, pipes and hoses of vulcanized rubber without fittings. Sheet and roll forms use a different heading, so tubes and sheets should be listed separately on the invoice when both are shipped. The importer's customs broker should confirm the local sub-heading.