Since 1981One stop for all your HVAC&R needs
Sheet thicknesses
Unfaced
Standard plain, unfaced nitrile rubber insulation sheet. Flexible, closed-cell elastomeric material for duct insulation, piping, equipment and other thermal-insulation work where the specification allows.
Plain on both faces, with no foil or adhesive.
Foil on one side
Nitrile rubber insulation sheet with aluminium foil facing on one side only, for work that needs a foil-faced finish, subject to project specifications. Not the same product as plain sheet or self-adhesive sheet.
Foil thickness, reinforcement and facing specification are not stated here and are confirmed per brand on enquiry.
Adhesive on one side
Nitrile rubber insulation sheet with pressure-sensitive adhesive on one side, supplied with a removable protective release liner. The liner is peeled away during installation to expose the adhesive surface. For ducting, equipment and insulation-lining work.
Not foil faced. Whether the adhesive suits a surface or installation condition has to be confirmed for the job.
Suitable for contractors, large projects and bulk procurement. Full factory roll supply. Roll length, width and coverage depend on the manufacturer and the thickness, so they are confirmed on enquiry.
Suitable for smaller requirements, repairs, maintenance and site-specific projects. Available in loose quantities or cut pieces, subject to stock and cutting requirements. Tell us the quantity or area you need.
| Sheet type | Thicknesses | Fire classes | Supply |
|---|---|---|---|
| Plain nitrile sheet | 6, 9, 13, 16, 19, 25, 32 mm | Class 1 / Class 0 | Full roll / Loose |
| One-side aluminium foil faced | 6, 9, 13, 16, 19, 25, 32 mm | Class 1 / Class 0 | Full roll / Loose |
| One-side self-adhesive with liner | 6, 9, 13, 16, 19, 25, 32 mm | Class 1 / Class 0 | Full roll / Loose |
Choose the sheet you need and send it to Refrigeration Centre on WhatsApp. Availability and price are confirmed on enquiry.
Class 0 and Class 1 nitrile rubber insulation tubes are available across a wide range of inner diameter (ID) sizes and wall thicknesses. Specific size, thickness and grade combinations are subject to stock confirmation.
Class 1 is listed in 24 sizes up to 4-1/4″ with 6, 9, 13, 19 and 25 mm wall. Class 0 is listed in 27 sizes up to 4-1/2″ with 6, 9, 13, 19, 25 and 32 mm wall. 3-1/4″, 4″ and 4-1/2″ inner diameters, and the 32 mm wall, are Class 0 only. 16 mm is a sheet thickness and is not listed for tube.
Pick the inner diameter (ID), wall thickness and grade, then send the enquiry on WhatsApp. The chosen size is highlighted in the table below.
| Size (inch) | Size (mm) |
|---|---|
| 1/4″ | 6 mm |
| 3/8″ | 10 mm |
| 1/2″ | 13 mm |
| 5/8″ | 16 mm |
| 3/4″ | 19 mm |
| 7/8″ | 22 mm |
| 1″ | 25 mm |
| 1-1/8″ | 28 mm |
| 1-1/4″ | 32 mm |
| 1-3/8″ | 35 mm |
| 1-1/2″ | 38 mm |
| 1-5/8″ | 42 mm |
| 1-3/4″ | 45 mm |
| 1-7/8″ | 48 mm |
| 2″ | 51 mm |
| 2-1/8″ | 54 mm |
| 2-3/8″ | 60 mm |
| 2-1/2″ | 63 mm |
| 2-5/8″ | 67 mm |
| 2-7/8″ | 73 mm |
| 3″ | 76 mm |
| 3-1/8″ | 79 mm |
| 3-1/4″ | 83 mm |
| 3-1/2″ | 89 mm |
| 4″ | 102 mm |
| 4-1/4″ | 108 mm |
| 4-1/2″ | 114 mm |
| Comparison | Class 1 | Class 0 |
|---|---|---|
| Test standard | BS 476 Part 7 | BS 476 Part 7 and Part 6 |
| What it measures | Surface spread of flame across the insulation’s surface. | The same surface-spread-of-flame result, plus fire propagation, which is how much heat the material adds to a fire in its early minutes. |
| Requirement | Class 1, the best of the four Part 7 classes. | Class 1 surface spread of flame, plus a Part 6 fire propagation index (I) of no more than 12 and sub-index (i1) of no more than 6. |
| Typically asked for | Where the specified fire-performance requirements allow it. | On projects with more demanding fire-performance specifications, such as commercial buildings and escape routes. |
| Tube range at Refrigeration Centre | 24 sizes, 1/4″ to 4-1/4″, in 6, 9, 13, 19 and 25 mm wall. | 27 sizes, 1/4″ to 4-1/2″, in 6, 9, 13, 19, 25 and 32 mm wall. |
| Sheet range at Refrigeration Centre | All seven thicknesses, in all three sheet types. | All seven thicknesses, in all three sheet types. |
More on the difference: Class 0 vs Class 1 in the questions below.
L'ISOLANTE K-FLEX, Italy
K-FLEX India is the Indian subsidiary of L'ISOLANTE K-FLEX and makes elastomeric foam insulation at its plant in Pune. K-FLEX ST comes as tubes and sheets for refrigeration, air-conditioning, heating and plumbing systems.
FEF ranges named on its website
By ALP Aeroflex India, Rudrapur
ALP Aeroflex India is a joint venture of ALP Overseas of India and Eastern Polymer Industries of Thailand. It makes EPDM and nitrile rubber insulation sheets, tubes and accessories for HVAC&R, with its main plant in Rudrapur, Uttarakhand.
Thermal insulation ranges named on its website
Superlon Worldwide, Malaysia
Superlon was incorporated in Malaysia in 1992 and makes NBR (nitrile rubber) foam insulation. It reports more than 30 years of manufacturing experience and lists thermal insulation and HVAC accessories among its product groups.
Thermal insulation products named on its website
Brand names and logos belong to their owners. Descriptions come from each manufacturer's own website, checked 18 October 2026. Not every product type, thickness, size or fire class is made by every brand. Brand, grade, size, availability and price are confirmed on enquiry.
Nitrile tube on the liquid and gas lines of air-conditioning systems, matched to the copper pipe’s outside diameter.
Tube sizesClosed-cell tube for refrigeration lines. Suction and low-temperature lines usually need a thicker wall, so follow the specification.
Tube sizesNitrile rubber tube and sheet for chilled-water lines and equipment where the specification calls for closed-cell elastomeric insulation.
EnquireSheet for duct insulation, plain, foil faced or self-adhesive, depending on the finish the specification asks for.
Sheet typesSheet insulation for plant rooms, air-conditioning equipment and insulation-lining work. Self-adhesive sheet suits lining where the adhesive suits the surface.
Sheet typesLoose and cut quantities of sheet and tube for repairs and small jobs. Tell us the area or length you need.
Supply optionsRefrigeration Centre stocks nitrile rubber tube insulation in two grades. Class 1 comes in 24 sizes from 1/4″ (6 mm) to 4-1/4″ (108 mm), with 6, 9, 13, 19 and 25 mm wall generally available. Class 0 comes in 27 sizes from 1/4″ (6 mm) to 4-1/2″ (114 mm), with 6, 9, 13, 19, 25 and 32 mm wall generally available. Choose the inner diameter (ID) to match the copper pipe’s outside diameter — 1/2″ insulation for 1/2″ (12.70 mm) pipe — so it fits snugly without stretching. See the full size list, then tell us the pipe size and length and we will match the tube.
Both are fire ratings based on the British Standard BS 476. Class 1 is the best of the four classes in the BS 476 Part 7 surface-spread-of-flame test, so flame spreads very little across the insulation’s surface. Class 0 is stricter: the material must reach Class 1 and pass the BS 476 Part 6 fire-propagation test with an index (I) of no more than 12 and a sub-index (i1) of no more than 6, which means it adds less heat to a fire in its early minutes. Class 1 nitrile is common on AC and refrigeration lines in homes and smaller premises; Class 0 is usually specified where a building’s fire code or the consultant calls for it, often in commercial buildings, hospitals, malls and escape routes. If the project specification names a class, follow it. Refrigeration Centre stocks both: Class 1 in 24 sizes up to 4-1/4″, and Class 0 in 27 sizes up to 4-1/2″, including 32 mm wall. See the size list.
Insulation must be thick enough to keep its outer surface above the dew point of the surrounding air. Split-AC lines are commonly insulated with about 9–13 mm of nitrile; suction lines, long exposed runs, humid coastal sites such as Chennai, and chilled-water or low-temperature refrigeration lines usually need thicker insulation, 19 mm or more. Where the AC maker or the project specification gives a thickness, follow it. Nitrile tube from Refrigeration Centre is generally available in 6, 9, 13, 19 and 25 mm wall, and Class 0 also in 32 mm.
Yes. Insulate the liquid line and the gas line separately along their full length, including the flare joints. In most split ACs both lines run cold in cooling mode, and in heat-pump units the gas line runs hot, so bare pipe sweats and loses capacity. Wrapping both lines in one sleeve lets them exchange heat; tape them together only after each has its own insulation. See liquid and suction lines.
A pipe sweats when its surface is colder than the dew point of the surrounding air. Common causes are gaps in the insulation, insulation too thin for the humidity, insulation squashed by tight ties or tape, and flare joints left bare. Fix it by closing every gap, sealing the joints and, in humid locations, moving up to a thicker wall.
Nitrile rubber (NBR) and EPDM are flexible closed-cell elastomeric foams used on refrigerant and chilled-water lines; nitrile is the usual choice for AC lines, while EPDM tolerates higher temperatures and outdoor weathering better. XLPE (cross-linked polyethylene) is a lighter, lower-cost closed-cell foam. Glass wool and rock wool are fibrous, suited to ducting and hot surfaces, and need a vapour barrier before they can be used on cold lines.
Yes. Elastomeric insulation such as nitrile breaks down in sunlight, so outdoor runs need a cover — UV-resistant wrapping tape, a protective coating, or aluminium cladding sheet on long or commercial runs. Refrigeration Centre stocks aluminium cladding sheet and wrapping tapes for this.
Yes. Acoustic lining for ducting and plant rooms is stocked alongside the thermal insulation range.
Yes. Refrigeration Centre deals in nitrile rubber insulation sheet with aluminium foil facing on one side, in 6, 9, 13, 16, 19, 25 and 32 mm, in Class 1 and Class 0, as full rolls or loose quantities. It is a different product from plain sheet and from self-adhesive sheet. Foil thickness, reinforcement and facing specification are not stated here, so ask for the details of the brand you need. Thickness, grade and supply format are confirmed for stock and price on enquiry. See the sheet types.
Yes. Self-adhesive sheet has pressure-sensitive adhesive on one side and comes with a removable protective release liner, which you peel away during installation to expose the adhesive. It is not foil-faced sheet. It is dealt in the same seven thicknesses, in Class 1 and Class 0. Whether the adhesive suits a particular surface or installation condition has to be confirmed for the job, so tell us where it will be fitted. Prepare an enquiry.
Yes. Full rolls suit contractors, large projects and bulk buying. Loose or cut quantities suit smaller jobs, repairs and maintenance, subject to stock and cutting requirements. Roll length, width and coverage depend on the manufacturer and the thickness, so they are confirmed on enquiry. Tell us the area or quantity you need. See the supply options.
Sheet comes in 6, 9, 13, 16, 19, 25 and 32 mm. Tube wall comes in 6, 9, 13, 19, 25 and 32 mm; 16 mm is listed for sheet only, and 32 mm tube wall is Class 0 only. Specific size, thickness and grade combinations are subject to stock confirmation. See the sheets and the tube sizes.
K-FLEX, ALP Aeroflex (the Aerocell and A-Flex ranges) and Superlon. Not every product type, thickness, size or fire class is made by every brand, so tell us the brand, grade and size you need and we will confirm what is available. See the brands.
Yes. Refrigeration Centre is a wholesale and retail HVAC&R stockist in Parrys, Chennai, and ships across India. Contractors and bulk buyers can ask for trade pricing on full rolls and tube quantities, and smaller needs are supplied loose or cut. Availability and price are confirmed on enquiry. Send a part list.
