Insulation tube

Insulation tube — technical data

Property	Class B	Class 0 same values
Cell structure	Closed cell	—
Material	NBR / EPDM	—
Density	65 kg/m³ standard · 55–90 kg/m³ to order	—
Thermal conductivity λ at −20 / 0 / +40 °C	0.030 / 0.032 / 0.037 W/(m·K)	0.030 / 0.032 / 0.037 W/(m·K)
Water vapour permeability	1.96 × 10⁻¹¹ g/(m·s·Pa)	—
Moisture resistance factor μ	≥ 10,000	—
Oxygen index	≥ 32 %	—
Flammability / smoke density	Self-extinguishing / smoke density 25–50	—
Water absorption	≤ 5 %	—
Service temperature	−57 °C to +125 °C	—
Flexibility / ozone resistance	Excellent / no crack	—
Standard length	1.83 m
Carton	1850 × 320 × 360 mm

Values are nominal production figures, tested per batch. Density, wall thickness and colour are produced to the customer's specification.

— means the value is identical for Class B and Class 0.

Inner diameter 6–89 mm (1/4″–3-1/2″) · wall thickness 6–50 mm (1/4″–2″). Intermediate sizes produced on request.

Where this tube is used

The same closed-cell NBR tube is specified across four very different duty ranges. What changes is the wall thickness and the jacket — not the material.

Chilled water and DX lines, +4 to +12 °C

The common case, and the one that fails first when the material is wrong. A chilled line sits below the dew point of most plant rooms for much of the year, so the insulation surface has to stay above it. Closed cells plus a moisture resistance factor of μ ≥ 10,000 keep water vapour from travelling through the wall and condensing against the cold pipe — the mechanism that turns a cheap open-cell or PE product into a wet, dripping line within one season.

Refrigerant suction lines, −40 to +10 °C

Service temperature of the material is −57 °C to +125 °C, so suction lines are inside the range with margin. The flexible closed-cell structure is what matters here: it follows bends and offsets without cracking, and it stays flexible at low temperature instead of going brittle the way rigid foams do.

Heating and domestic hot water, up to +125 °C

Thermal conductivity rises with temperature — 0.030 W/(m·K) at −20 °C, 0.032 at 0 °C, 0.037 at +40 °C — so a wall thickness sized on the cold figure will under-perform on a hot line. Size hot lines on the λ at the actual mean temperature, not on the catalogue's headline number.

Heat pump and solar thermal pipework, outdoor

The material handles the temperature; it does not handle ultraviolet. Outdoors, the tube must be protected — aluminium foil facing, a painted finish, or a metal jacket — otherwise the surface degrades in a season or two. Say so in the specification rather than discovering it on site.

Condensate lines, duct connections and AHU tails

Short runs, awkward geometry, frequent direction changes. Tube is cut and glued on site, so the joint quality depends on the installer: a 1 mm gap at a joint is a cold bridge and a future drip.

How to specify the wall thickness

Thickness is not a catalogue decision — it is an output of four numbers about your line. Give us these and we return the wall thickness and the class that meets your code:

Pipe outside diameter — The tube is sized by inside diameter to slip over the pipe: 6–89 mm ID in the standard range, matched to copper, steel and stainless outside diameters.
Medium temperature — The coldest condition the line actually sees, not the design set point. A chilled water line that runs at +7 °C but is shut down overnight at +2 °C must be sized on +2 °C.
Ambient temperature and relative humidity — The pair that decides the dew point. A plant room at 32 °C and 80 % RH is a far harder case than the same room at 24 °C and 50 % RH — same pipe, different thickness.
Location and code — Indoor or outdoor, exposed or in a ceiling void, and which classification your authority requires. This decides Class B or Class 0, and whether a jacket is needed.

If the wall is undersized the surface drops below the dew point and the line runs wet: insulation becomes a reservoir, corrosion under insulation starts, and the drip stains the ceiling below. Over-sizing costs foam and eats the clearance in a plant room. It is worth ten minutes to size it once.

How the wall thickness is calculated →

Installation points that decide whether it works

Cut square with a sharp blade. A crushed or ragged cut face does not close up, and the gap is where the vapour gets in.
Glue both faces, let the adhesive go tacky before pressing, then hold until it grabs. Contact adhesive is not a gap filler — it holds two clean surfaces together.
Mitre elbows at 45° from both sides rather than bending a straight length round the corner. A bent length is thinner on the outside of the bend and kinked on the inside.
Do not compress the tube to make it fit a smaller pipe. Compression reduces wall thickness at exactly the point where you needed it.
Keep the vapour barrier continuous: glue every longitudinal seam, tape every butt joint with the matching NBR tape, and close the ends at flanges, valves and supports.
At hangers and cleats, use a vapour-tight saddle or a sleeve of the same material. A bare metal clamp crushes the wall and creates a condensation point.

Questions buyers ask before ordering

What wall thickness do I need for a chilled water pipe?

It depends on pipe diameter, the coldest medium temperature, and the ambient temperature and humidity of the space — the wall has to keep the insulation surface above the dew point. Send us those four numbers and we return the wall thickness and the class for your standard. Sizes in the standard range go from 6 mm to 89 mm inside diameter with wall from 6 mm to 50 mm.

Can the tube be installed outdoors?

The material is rated −57 °C to +125 °C, so temperature is not the limit — ultraviolet is. Outdoors the tube needs protection: aluminium foil facing, a coating, or a metal jacket. Without a jacket the surface degrades within a season or two.

What is the difference between Class B and Class 0?

Both are produced from the same formulation with the same thermal and moisture data; the designation follows the fire classification your market requires. The material itself is self-extinguishing with an oxygen index of at least 32 % and smoke density in the 25–50 range. Tell us the classification your authority or your customer's specification calls for and we produce to it — do not assume one market's class number means the same thing in another.

How is the tube packed and what is the standard length?

Standard length is 1.83 m per piece, packed in cartons of 1850 × 320 × 360 mm. Wall thickness and inside diameter decide how many pieces go into a carton, and that packing list goes out with the quotation.

Can you produce to our own specification?

Yes. Density is 65 kg/m³ as standard and can be produced from 55 to 90 kg/m³, wall thickness and colour are made to the customer's specification, and both adhesive-free and self-adhesive versions are available. Production figures are nominal and tested per batch, so the test report that accompanies the shipment is what your incoming inspection should be checked against.