Double-Layer Braided High-Temp Insulating Sleeve
Double-Layer Braided High-Temp Insulating Sleeve (HTE-411 TMM series) is two braided layers of glass yarn in the catalogued high-density construction: a coating-free, non-shrink sleeve for heat containment on high-temperature equipment. The second braid is the point of the product: it closes the open diamonds a single braid leaves and doubles the fibre mass in the wall. The catalogued range is -60 °C to +550 °C; the split between continuous and short-duration duty is pending verification, so we size against your actual duty cycle. Send the bundle OD and the largest end and we return the size.
Specification
| Material | Fiberglass braid, double layer |
|---|---|
| Operating temperature | -60 °C to +550 °C catalogued; continuous vs short-term split pending verification |
| Shrink ratio | Non-shrink |
| Wall type | Double-layer high-density braid |
| Size range | HTE-411 TMM series |
What the double braid actually is
Each layer on its own is a lattice: glass strands cross at an angle and leave open diamonds, so a single braid never covers the full circumference and its wall is one filament thick at any point. Doubling the braid closes most of the remaining open area, doubles the fibre mass between the heat source and the line, and gives a moving edge two layers to cut through instead of one. The outer layer also takes the direct rub and radiant load first, sparing the inner layer. How the two layers relate to each other (bonded, stitched or free) is part of the pending specification, so treat the pair as one sleeve during installation. With no coating on the glass, there is no compound to age, crack or burn off; the service limit is set by the glass and its finish, which is exactly why the continuous-versus-short-term temperature split must come from test data rather than a generic glass figure. The braid holds position by its own tension. It does not shrink.
Where Double-Layer Braided High-Temp Insulating Sleeve is used
Primary applications: High-temp equipment insulation. Duty where a coating-free double braid carries the thermal load and the cable keeps its own dielectric.
How to select the right size
Sizing a double braid differs from a single braid in three ways:
- ID and expansion. The braid expands in diameter as it shortens. The ID must pass the largest end : terminal, lug, connector boot : not just the run; if the end is bigger than the cable, size to the end and dress with a clip.
- Wall bulk and bend. Two layers mean more bulk and less stretch than a single braid. Check the minimum bend radius and the clearance in your channel or gland before ordering; where bulk blocks the route, a single-layer construction may fit better.
- Duty at temperature. Because the continuous and short-term limits are not yet split, quote us the hold temperature and the time at peak; we size against the verified figure, not the catalogue maximum.
Common Failure Modes & How to Prevent Them
These are the issues most often seen when installing or specifying Double-Layer Braided High-Temp Insulating Sleeve, with the root cause and the prevention or fix for each.
The two braided layers shifted apart during install
Root cause: The layers are independent braids. Forcing the sleeve over a sharp edge or a larger end drags the outer layer ahead of the inner one, leaving uneven coverage at the nose.
Fix: Open the ID fully before feeding (push the braid back on itself or use a tapered dummy), and pass both layers over the end together. Size the ID for the largest feature, not the run.
The cut end shed filaments into the assembly
Root cause: Glass braid has no self-edge. A cut end frays into fine filaments that work into connectors and terminations.
Fix: Cut to length only after the sleeve is in place, then dress the end: glass tape wrap, clamp or ferrule. A hot trim burns off the fibre finish only; glass does not melt-seal, so do not rely on heat to close the end.
The double wall would not make the bend
Root cause: Two braid layers add bulk and reduce stretch. A route sized by experience with single-layer braid kinks or bridges the sleeve at tight corners.
Fix: Check bend radius and channel clearance against the double wall before ordering. Where bulk blocks the route, state it at RFQ. A single-layer or coated construction may be the right trade.
The sleeve was counted on as the dielectric
Root cause: The word insulating was read as a voltage rating. An uncoated braid is an open lattice with air paths through the wall; it has no verified withstand value.
Fix: Keep the conductor's own insulation as the dielectric and use this sleeve for its thermal and mechanical duty. If the design needs the wall itself rated, request test data before design-in.
The 550 °C figure was applied as a continuous rating
Root cause: The catalogue range -60 °C to +550 °C was taken as a continuous duty figure. The continuous and short-duration limits have not been split against test data yet.
Fix: Size to the verified limit, not the catalogue maximum. Send hold temperature and time at peak; we confirm the applicable figure and, where needed, propose a construction matched to continuous duty.
Frequently asked questions
What does the second braid layer add?
A single braid is a lattice: strands cross at an angle and leave open diamonds, so one layer never covers the full circumference and its wall is one filament thick at any point. The second layer closes most of the remaining open area, doubles the fibre mass between the heat source and the line, and gives a moving edge two layers to cut through instead of one. Treat the pair as one sleeve and do not split the layers during installation.
Is +550 °C a continuous or short-duration condition?
That split has not been verified yet. The catalogued range runs from -60 °C to +550 °C, but we are not publishing 550 °C as a continuous rating until it is confirmed against test data. Send your duty cycle (hold temperature and time at peak), and we confirm the applicable limit before you order.
How should braid density and ID be specified?
Specify ID from the bundle: cable or hose OD plus the largest feature (connector, lug, splice) plus margin, because the double wall stretches less than a single braid. Density is catalogued as high density; the exact coverage figure and picks per inch are part of the pending data pack. If your drawing calls a minimum coverage, send it and we quote against that figure.
How does installation over terminals and connectors work?
It is a non-shrink slip-on braid: push it back on itself to shorten the sleeve and open the ID, pass the assembled end (terminal, connector boot, lug) through the expanded eye, then release so the braid settles over the run. If the end is larger than the run, size the sleeve to the end and dress it with a clip.
How do I manage the cut ends of a glass braid?
Glass braid has no self-edge and a cut end sheds fine filaments. Cut last, not first: slip the full length, dress the remote end with a wrap of glass tape, a clamp or a ferrule, then trim to length. A hot trim only burns off the fibre finish. Glass fibre itself does not melt-seal, so never rely on that.
Does "insulating" mean I can rely on it for voltage isolation?
No. Insulating in this product name refers to thermal insulation duty. An uncoated braid is an open lattice. Air moves through it, and there is no verified withstand value across the wall. Keep the conductor's own insulation as the dielectric; if your design requires the sleeve wall itself to carry a voltage rating, request test data at RFQ.
Request a quote for Double-Layer Braided High-Temp Insulating Sleeve
Send the bundle OD, the largest end, the duty cycle at temperature and the length. We return the HTE-411 TMM size, the confirmed temperature split and lead time.
Size range & specification notes
HTE-411 TMM series. Published sizes remain as catalogued; the ID range, per-layer wall and density figures will be added once confirmed.