All four bands
Closing an end where a torch is not allowed
In air, splash zone, buried or submerged: the band still decides what the end needs, and a refused hot-work permit decides whether you may fit it where the end is standing.
Declared before the argument, not after it
Every cap described anywhere on this site is heat-shrink cross-linked polyolefin or moulded polyvinyl chloride. No cold-shrink end cap is supplied through this site, and no cold-shrink end-cap datasheet sits in its sources. The cold-shrink column below is therefore written from published mechanism alone: no dimension, no temperature, no test result, because there is nothing here to take one from.
Five places where the permit is refused
A hot-work permit authorises a flame, a spark or a hot surface somewhere that would not otherwise tolerate one. Refuse it and nothing about the end has altered: same band, same outside diameter, same ingress to survive. One method of getting a cap onto it has been withdrawn, and that is all.
Five settings account for most refusals. A gas or petrochemical site may allow no ignition source in a classified area while the plant runs. An operating marina keeps timber, glassfibre hulls and a fuel berth within a few metres, so refusal usually covers the whole pontoon rather than one pile. An energised or live-adjacent network puts a naked flame beside conductors nobody wants to earth for a capping job. A confined space needs two permit systems satisfied together, and a torch spoils the atmosphere test the second depends on. A vessel or platform under permit-to-work commonly suspends hot work during cargo transfer or bunkering, so the window is a shift pattern rather than a decision.
Three moves follow: change the part, change the permit window, or change the place. The third gets forgotten and is usually cheapest, because a permit attaches to a location rather than to a cable. An end that cannot be closed on a refinery hardstanding is often closed in a shop where hot work is routine and arrives sealed — routine at a cable works, set out under closing an end at the works, and the same trick behind the end cap with a pulling eye.
Where the work must happen anyway, this is the whole flame-free inventory here. A dry cut cable end takes the moulded push-on cap; a crimped lug or stud in a panel takes the moulded terminal cap; a crown or a pile top has a PVC version alongside the torch-applied one, on pole caps and dock pile caps. Below the air band the list stops. Nothing flame-free in these sources carries an adhesive lining, so a buried or submerged end cannot be given a sealed closure without heat.
Cold shrink is what a specifier reaches for next, and it belongs on another domain in this network rather than in a paraphrase here: mechanism and rating sit on cold shrink, where those datasheets live. Two things before you go. That range is rated to 1.1 kV, which puts most distribution work outside it, and it is tube rather than a capped end. Neither is a reason to avoid it; both are reasons to check the rating before a permit argument is settled on the assumption a flame-free equivalent exists.
Three answers to one refused permit
Read the middle column as an outline, not as data. It is here because the reader who lands on this page has usually been told cold shrink is the answer.
| Decision point | Heat-shrink cap | Cold shrink | Push-on PVC cap |
|---|---|---|---|
| Hot-work permit to fit it | Yes. Propane or butane torch above 125 °C (257 °F) | No. Recovery is mechanical, no heat input | No. It goes on by hand |
| Installer skill | Trained. Soft blue flame, closed end first, no scorching | Low. Withdraw the core, the part recovers itself | None required, in the manufacturer's own wording |
| Time at the end | Torch time, then cool-down before mechanical strain | Core withdrawal only, no cool-down to wait out | Immediate, nothing to cure |
| State on the shelf | Relaxed. Stable in its expanded shape until heated | Loaded. Held stretched on its core from manufacture | Relaxed. Moulded at its finished size |
| On an irregular or stepped sheath | Hot-melt lining flows into the step and bridges it | Elastic interference fit. Nothing flows | Interference fit on the outside diameter, nothing more |
| Published ingress rating | IP68 where the adhesive lining is specified | None held in this site's sources | None anywhere on the datasheet |
| Opening the end again | Cut it off, fit a fresh one | One-way once the core is out | Pulls off and goes back on |
| Relative unit cost | Dearer than the PVC cap, on the maker's own comparison | No figure held here, and none guessed | The economical option, and why odd jobs land in it |
| Continuous temperature | −40 °C to +110 °C (−40 °F to 230 °F) | Not held in these sources | −20 °C to 115 °C (−4 °F to 239 °F) |
| Test methods published here | ASTM D638, D792, D2240, D570, D2671, D149, D257, D150; ESI 09-11; IEC 216 | None. No cold-shrink end-cap datasheet exists here | ASTM D149, D638, D792, D2240; IEC 216; UL 94-V0 |
Where the permit does not get the last word
Three cases force heat onto the job whatever the permit desk says. Three mean the flame was never needed.
- A damaged or stepped sheath needs something that flows. The lining melts into a crack, an oval, an armour step or a knife score and sets there. An interference fit only follows the surface it is pushed over.
- A specification naming IP68 is naming heat-shrink. In these sources that figure appears against the adhesive-lined constructions and nothing else, so no flame-free part here can be offered against it.
- 12 kV/mm sits on two datasheets here, not one. Both the polyolefin cap and the moulded PVC cap record that minimum, so a dielectric clause at that level does not drag a torch onto site. No source here records any dielectric figure for a cold-shrink cap. The methods are explained once, on what an end-cap datasheet proves.
- In air, the push-on cap is sufficient. An indoor panel, a covered bay, a drum under a roof: specifying a torch-fitted part into those buys a permit argument and no extra protection.
- Weathering, moisture and contamination is the PVC sheet's claim, and that claim is a cover rather than a seal. No adhesive on it, no ingress figure on it. Protection from what lands on the end, not from what stands against it.
- At a pile top the flame-free option is thinly documented. The torch-applied pile cap publishes five sizes spanning 140 mm to 460 mm (5.5 to 18 in); the PVC version publishes no size range here at all, so a marina buying flame-free sends measured diameters instead of picking off a chart.
The questions a refused permit produces
Will a hot-air gun get me round the permit?
I was searching for a particular brand of cold-shrink end cap.
Does flame-free mean I lose the seal?
The end is energised and I still cannot get a permit.
Where to go from a refused permit
Two change the part, two change the place. Try the second pair first.
- A push-on cap for an end that stays in airThe only flame-free cable-end part here
- A crimped terminal in a panel is an open end in airFlame-free by construction, inside the box
- Closing an end at the works, before it sees weatherMove the work to where the permit exists
- A marina asset crosses all four bands in one memberTimber, fuel and a live berth in a few metres
- Insulcap heat-shrink cable end caps, sealed for burialWhat a flame-free choice gives up
- Fitting a cap with a gas torch, on five substratesWhat the permit is being asked to authorise
Send the permit position before the diameter
Two lines move the answer further than any dimension: whether hot work will be authorised where the cap is fitted, and whether the end could be closed somewhere it will be. Add the band and the outside diameter.