Aluminum Foil Fiberglass Fire Pipe
A passive thermal barrier for exhaust runs and hot pipework: an aluminum foil outer face that reflects radiant heat, over a fiberglass core that slows conducted heat, with a fire-resistant layer in the build. Slip-on, non-shrink, closed with end clamping. One correction from the earlier catalogue: the "up to 1000°C short-term" figure is on hold on this page until its test basis (exposure type, distance, duration, pass criterion) is verified; aluminium as a metal melts near 660°C, so a higher figure can only ever describe a specific test geometry, not a contact rating. Design against the continuous rating once issued (data note below). Send the pipe OD and the radiant source details and we size the sleeve.
How the layers work — and what each one cannot do
The sleeve combines two heat mechanisms, and keeping them separate is the whole specification discipline:
- Aluminum foil : radiant reflection. The bright outer face has low emissivity: across an air gap, it bounces radiant heat back toward the source instead of absorbing it. Reflection is the foil's only job. It stops working when the gap closes (contact loads by conduction, which foil does not block) and it degrades when the face is scuffed, dented or oxidised dull.
- Fiberglass core : conducted-heat barrier and body. The inorganic fibrous wall is porous: the trapped air does the insulating, and the glass carries the temperature backbone. It slows heat that reaches it for a limited time : it is a barrier, not a perpetual insulation. Compaction or wetting closes the air spaces and collapses its performance.
- Fire-resistant layer : flame-exposure support. Its role is to keep the core coherent under flame contact. Flame-impingement duration limits for this build are part of the pending test basis.
Four temperature values, not one. The catalogue printed a single "up to 1000°C short-term": that merges four different numbers that behave differently: radiant reflection performance (source temperature vs distance, air-gap dependent), contact temperature (limited by conduction into the core and by the foil itself), continuous service temperature (the sustained rating, to be issued), and short-term exposure (test-basis dependent, currently on hold). Until the verified figures arrive, this page publishes none of them and does not present the product as direct-contact 1000°C insulation.
Where Aluminum Foil Fiberglass Fire Pipe is used
Primary applications: exhaust and high-temperature pipe protection. Runs passing near or alongside hot lines where the threat is mostly radiation across an air gap: vehicle and equipment exhaust proximity, heated air ducting, industrial hot-air runs. Installed as a slip-on barrier with clamped ends; no shrink, no adhesive.
How to select: duty, gap, size, closure
- Radiant source or contact? State which the run sees. Radiant duty with an air gap is this product's native job; sustained contact or flame impingement needs a different construction or physical standoff.
- Continuous temperature. Give the sustained surface temperature of the protected line; the continuous rating for this build is issued from the verified data (data note).
- Gap geometry. Reflection needs clearance : keep the foil face off the hot line where the route allows. Where contact is unavoidable, treat the position as conductive duty and confirm the build with us.
- Pipe OD, bends, length. Sleeve ID clears the pipe plus cladding; route length with bend allowance; ends closed with band clamps or stainless ties over the foil.
- Environment. Moisture or chemicals on the foil face change the corrosion picture : state the environment so the build is confirmed.
Specification
| Material | Aluminum foil outer face + fiberglass core + fire-resistant layer |
|---|---|
| Primary function | Radiant heat reflection + conducted-heat barrier |
| Operating temperature | Under verification : continuous and short-term values to be issued separately (see data note) |
| Shrink behaviour | Non-shrink slip-on |
| Closure | End clamps / stainless ties over the foil; seam construction per pending documentation |
| Colors | Silver (foil face) |
Common Failure Modes & How to Prevent Them
These are the failures specific to a foil-faced radiant barrier sleeve, with the root cause and the prevention for each.
The sleeve was installed touching the hot line
Root cause: The route left no air gap, so the foil face sat against the hot surface. Reflection stopped at contact and the load passed into the core by conduction: the one mechanism the foil contributes nothing to.
Fix: Preserve a gap between foil and source wherever the route allows; use standoffs or clips to hold it. Where contact is unavoidable, confirm the conductive-duty build before installation.
The foil face was scuffed or dented during install
Root cause: The sleeve was dragged over brackets or handled with tools on the foil side. Creases and scuffs raise the face's emissivity: a dull, damaged face absorbs radiant heat instead of reflecting it.
Fix: Handle by the core, not the face; slide over routes with the clamps loose; inspect the face after install and replace sections with heavy foil damage.
The core compacted and lost its insulation
Root cause: The sleeve was clamped hard at mid-span or crushed against the pipe, closing the fiberglass's air spaces. Compacted fiberglass conducts; the barrier became a wick.
Fix: Clamp at ends over the foil only, support mid-span without crushing, and keep the sleeve's round section along the run.
Water sat in the sleeve
Root cause: The run collected condensation or wash-down water inside the sleeve. Wet fiberglass loses its insulating air spaces and holds moisture against the line and the foil.
Fix: Provide drain points at the low end of vertical runs, and state wash-down exposure at RFQ so the build and closure are confirmed for a wet environment.
The 1000°C figure was copied into a contact-duty design
Root cause: The old catalogue figure was read as a direct-contact or flame rating and used to clear a design with sustained hot-surface contact. The verified basis never existed, and aluminium's melting point makes a contact reading impossible at that figure.
Fix: Design radiant duty from the verified continuous rating and source-distance data once issued; treat every above-660°C figure as a test-geometry result, never a contact rating; hold contact-duty designs until the fire-test basis is verified.
Frequently asked questions
What does the short-term heat rating actually measure?
That is exactly what is being established. A short-term figure only means something with its test conditions attached: exposure type (radiant panel or flame contact), distance, duration and the pass criterion. The catalogue carried 1000°C short-term without any of those conditions, so the figure is on hold on this page until the test basis is verified and can be printed with it. Until then, design against the continuous rating once issued and treat peaks as unverified.
Is this intended for radiant heat or direct flame/contact?
Its primary job is radiant heat: the aluminum face is a reflector, and reflection only works against radiation, where the foil sees the hot source across an air gap. Direct contact is a different duty: pressed against a hot surface, the foil cannot reflect and the load passes into the fiberglass core by conduction, which the core resists for a limited time only. Sustained contact or direct flame impingement needs standoff spacing or a dedicated fire-barrier construction, and direct-contact temperature capability is not claimed on this page.
Which layer provides reflection versus mechanical insulation?
The aluminum foil is the reflection layer: low emissivity, it bounces radiant heat back toward the source. The fiberglass core is the mechanical insulation: a porous, inorganic fibrous wall that slows conducted heat and gives the sleeve its body and handling strength. The fire-resistant layer supports the core under flame exposure. Each layer fails differently: scuffed or torn foil loses reflection, compacted or wet fiberglass loses its insulating air spaces.
Why is an aluminum face limited on a hot pipe?
Aluminum melts around 660°C as a metal, so a figure above that cannot describe the foil face itself. It can only describe what the composite reflects or survives in a specific test geometry. That physics is one reason the 1000°C figure is being verified against its test basis before it is printed here. In practice the foil face also oxidises slowly at high temperature and dulls, which reduces its reflectivity long before any melting condition.
How is the sleeve installed and closed on the pipe?
Slip it over the pipe with clearance for any cladding, then close the run: secure both ends with band clamps or stainless ties over the foil, and on long runs support mid-span so the sleeve does not sag into contact with the hot line. Leave an air gap between the foil face and any nearby hot surface where the route allows: reflection needs the gap. Where the sleeve is supplied with a longitudinal seam, close it as specified; seam construction is part of the pending documentation.
Which pipe dimensions are needed to size it?
The pipe or cladding OD, the route length with allowance for bends, and the fixing positions. Then the duty: continuous surface temperature and any radiant source with its distance, stated separately. Send those and we return the sleeve ID, length and closure hardware. Available ID range per size is part of the pending documentation.
Request a quote for Aluminum Foil Fiberglass Fire Pipe
Send the pipe or cladding OD, the continuous temperature, the radiant source and its distance, route length and quantity. We return the sleeve size, closure hardware and the verified duty data for the order.
Size range & specification notes
Sleeve IDs are issued against pipe or cladding ODs; verified temperature data and seam construction are held in the data note above until confirmed.