Insulation Solutions by Application
Seven routes through the same problem: get the insulation right at the voltage, the geometry and the environment the part actually sees. Start from the duty, not from the catalogue.
How to use this page
- Start from the duty. Voltage class, geometry and environment narrow the material family faster than any data sheet comparison.
- Then open the route that matches. Each solution page carries the selection tables, the field failure modes, the FAQ and the product lines that fit it.
- If two routes look plausible, send us the drawing and the duty. We will tell you which one applies, and we will say when the answer is that you do not need a custom part at all.
Well Electric has been building insulation components since 2017, and the business before that goes back to 1998. Over that time the same conversations keep coming back: a buyer has a voltage, a space, a temperature and a deadline, and the catalogue does not answer the question directly. These solution pages are the answer to those conversations, written the way we would answer them on a call.
Route by duty
| What you are insulating | Voltage class | Deciding constraint | Route |
|---|---|---|---|
| High-temperature wiring, sensors, chemical exposure | LV to MV | Service temperature and recovery temperature on your line | Fluoropolymer Heat Shrink Tubing |
| Splices, connectors, harness joints that must stay dry | LV | Diameter spread on one joint and the seal conditions | Dual-Wall Adhesive Heat Shrink Tubing |
| Thermocouples, RTDs, micro coax, precision guides | Signal and LV | Wall thickness against response time and available space | Polyimide Capillary Tubing |
| Flange bolts, transformer clamping bolts, thread protection | Dielectric break | Sleeve fit to the shank and length head to nut | Mylar (PET) Tubing for Bolts |
| Fuse bodies, cutout tubes, arc-quenching liners | 1 to 36 kV | Whether the surface faces the arc, and the breaking duty | MV/HV Fuse Body Tubes |
| Breaker, interrupter and precision structural tubes | LV to HV | Concentricity and burst strength at a thin wall | Thin-Wall Filament Wound Micro Tube |
| Busbars, panel runs, battery pack conductors | LV to 35 kV | Geometry at bends and the joint detail | Busbar Insulation |
| A complete fuse or EV/ESS component set | LV to HV | Supply scope rather than material choice | Fuse Components and EV & ESS Insulation Components |
All solution routes
Fluoropolymer Heat Shrink Tubing
PTFE, FEP and PFA shrink tube. Choose on service temperature, recovery temperature and chemical duty. Above 260 °C continuous, none of them qualify.
Dual-Wall Adhesive Heat Shrink Tubing
2:1, 3:1 and 4:1 glue-lined tube for splices and connectors. Where the seal really comes from, and the four reasons a joint leaks later.
Polyimide (Kapton) Capillary Tubing
Bores from 0.05 mm and walls to 0.013 mm for thermocouple and RTD sheathing, micro coax and precision guides. Plus the moisture caveat.
Mylar (PET) Tubing for Bolts
Flange isolation sleeves, thread protection and transformer clamping bolts. M6 to M36 plus ANSI and DIN, cut to the stud and packed to count.
MV/HV Fuse Body Tubes
Vulcanized fiber, arc-quenching liner, epoxy composite and fiberglass from 1 kV to 36 kV. Which material is arc-facing and which is not.
Thin-Wall Filament Wound Micro Tube
Wall from 0.2 mm with no seam, close ID and OD, and high hoop strength. Where thin-wall parts actually fail, and how to machine them.
Busbar Insulation
Heat-shrink sleeve, dual-wall adhesive tube and insulated connection boxes for 800 V EV and ESS, sized to bar section and platform voltage.
Fuse Components
The supply scope for fuse makers: LV, MV and HV bodies, internal liners, end caps and the small parts around them.
EV & ESS Insulation Components
Battery pack and energy-storage insulation: busbar sleeves, cell and module spacers, connection boxes and thermal barriers.
What every route has in common
Drawn to your dimensions, not a catalogue number
Almost everything we ship is made against a drawing: ID, OD, wall, length, features and tolerances. Where a catalogue size does exist we will quote it, but we will also tell you when it is the wrong basis for the part.
Duty stated before material chosen
The voltage class, the continuous and peak temperature, the chemical exposure and the geometry each eliminate material families. Choosing the material first and fitting the duty afterwards is how most of the field failures we are asked to review start.
Documentation that matches the approval file
Material COA traceable to the incoming certificate, first-article inspection per your plan, in-process dimensional records and final inspection reports. On automotive and ESS programmes we work to IATF 16949 style PPAP expectations.
An answer when the answer is no
If the duty sits outside the material you asked for, we will say so and point at the correct family. Vulcanized fiber against an arc, polyimide in immersion, a fluoropolymer above 260 °C: those are all places where the honest answer saves you a field failure.
Prototype to production from one source
Prototype quantity and annual volume are quoted together, with tooling called out separately for the parts that need it. That keeps the sample stage from hiding a cost that appears at ramp.
Engineering review before quotation
Drawings are reviewed for feature depth, edge distance and remaining wall before the price goes out. If something on the print will not hold, we raise it at quotation rather than at first article.
Common questions
How do I know which insulation route applies to my part?
Answer three questions: what voltage class, what geometry including bends and joints, and what environment including temperature, moisture and chemistry. Those three narrow it to one or two material families. Then check whether the part is arc-facing, because that single fact removes several materials from the shortlist.
Do you have a minimum order quantity?
It depends on whether the size is stock or made to drawing. Standard bores ship in sample quantities. Custom tooling, special laminates and wound parts carry a minimum tied to the setup, and we state it at quotation rather than after the sample is approved.
Can you work from a sample instead of a drawing?
We can reverse-engineer a part, but for anything with a tolerance that matters we prefer a drawing, because the drawing tells us which dimensions are functional and which are nominal. From a sample alone we measure what exists, not what the assembly needs.
How long does a quotation take?
A catalogue-similar part can be quoted in a day. A custom part with tooling, a composite build or an arc-facing liner takes longer because the drawing goes through engineering review first. Sending the duty along with the drawing is what keeps that review short.
What documentation do you supply?
Material COA traceable to the incoming material certificate, first-article inspection per your plan, in-process dimensional records at each station and final inspection reports. Dielectric, immersion, salt-spray and burst tests are available on request where the duty calls for them.
Do you supply RoHS and REACH declarations?
Yes, for the standard grades across all our product families, with certificates per batch. If your programme needs a specific declaration format or a substance list, tell us at enquiry stage.
Can you handle both prototype and volume production?
Yes, and we quote both at the same time so the ramp cost is visible from the start. For machined and wound parts, tooling and setup are called out as separate line items rather than folded into a unit price.
What if my duty does not fit any material you make?
Then we say so. Above 260 °C continuous duty, high-voltage duties that require ceramic, or applications where the right answer is a standard commercial part rather than a custom one are all cases where we will tell you to look elsewhere. It costs us one order and it saves you a field failure.
How do I send a drawing?
Submit the RFQ form on any solution page and then email the drawing file to sale@wellele.com, quoting the same product name so we can match it. PDF, DWG and STEP are all fine. Note the dimensions you consider critical so the review can focus.
Where are you located, and who do you ship to?
Well Electric is based in Suzhou, Jiangsu, China, and we export worldwide. Production runs under ISO 9001:2015 with RoHS and REACH compliance across the standard grades. Lead time is quoted per part and per finish.