Heat Shrink Rain Shed (Insulshed)
Insulshed increases the surface creepage distance of cable termination cores without increasing tail length, and helps prevent tracking-related faults during the rainy season.
- ASTM D638
- ASTM D792
- ASTM D2240
Choose a size
Selection Chart
- ØA (min.)
- Overall diameter of the skirt
- Ds (min.)
- Internal diameter of the collar as supplied
- Df (max.)
- Internal diameter of the collar after free recovery
- Hs (min.)
- Height of the collar as supplied
- ∠° (min.)
- Angle of the skirt
- Tf
- Wall thickness after recovery (±10%)
| Code | ØA(min) | Ds(min) | Df(max) | Hs(min) | ∠°(min) | Tf(±10%) |
|---|---|---|---|---|---|---|
| GRS 130-1 | 90 | 36 | 15 | 20 | 10 | 2.5 |
| GRS 130-1 N | 94 | 41 | 13 | 33 | 20 | 2.5 |
| GRS 130-2 | 122 | 51 | 21 | 22 | 10 | 3.0 |
| GRS 130-2 N | 117 | 55 | 19 | 39 | 20 | 3.5 |
| GRS 130-3 | 135 | 67 | 31 | 26 | 10 | 3.0 |
| GRS 130-3 N | 135 | 75 | 32 | 40 | 20 | 3.5 |
| GRS 130-4 | 138 | 80 | 35 | 30 | 10 | 3.0 |
| GRS 130-5 | 138 | 105 | 35 | 35 | 10 | 3.0 |
| GRS 130-6 S | 200 | 120 | 50 | 50 | 10 | 4.5 |
| GRS 130-6 | 200 | 150 | 50 | 45 | 20 | 4.5 |
All dimensions are in mm. D: internal diameter; s: as supplied; f: after free recovery. Source: GALA INSULSHED Heat Shrink Creepage Extension Skirt (Rain Shed) sheet, Issue 2, January 2026.
Material properties
Technical Specification
| Properties | Value | Standard |
|---|---|---|
| Physical | ||
| Tensile Strength | 12 N/mm² (Mpa) (min.) | ASTM D638 |
| Ultimate Elongation | 350% (min.) | ASTM D638 |
| Density | 1.15 ± 0.2 gm/cm³ | ASTM D792 |
| Hardness | 45 ± 10 Shore D | ASTM D2240 |
| Water Absorption | 0.5% (max.) | ASTM D570 |
| Thermal | ||
| Accelerated Ageing | (120 °C for 500 hrs.) | ASTM D2671 |
| Tensile Strength | 11 N/mm² (Mpa) (min.) | ASTM D638 |
| Ultimate Elongation | 300% (min.) | ASTM D638 |
| Low Temperature Flexibility (-40 °C for 4 hrs.) | No Cracking | ASTM D2671 |
| Heat Shock (250 °C for 30 min.) | No cracking or flowing | ESI 09-11 |
| Shrink Temperature | 125 °C | IEC 216 |
| Continuous Temperature Limit | -40 °C to 100 °C | IEC 216 |
| Electrical | ||
| Dielectric Strength | 15 kV/mm (min.) | ASTM D149 |
| Volume Resistivity | 1 x 10¹⁴ Ohm.cm (min.) | ASTM D257 |
| Dielectric Constant | 5 (max.) | ASTM D150 |
| Resistant to track & erosion | No tracking, erosion or flame failure up to 3.25 kV for 20 min. | ASTM D2303 |
Source: GALA INSULSHED Heat Shrink Creepage Extension Skirt (Rain Shed) sheet, Issue 2, January 2026.
Dimensions & Drawings
A longer creepage path across the termination surface reduces the risk of a rain-driven flashover, without lengthening the termination itself. Insulshed adds that path as a series of shed rings.
Covered on this page
- Creepage Extension Skirt (Rain Shed) - INSULSHED
Features & Benefits
- Cross-linked polyolefin with non-tracking behaviour
- Internally coated with water-resistant mastic
- Suitable for indoor and outdoor applications
- No tracking, erosion or flame failure up to 3.25 kV for 20 minutes (ASTM D2303)
- Dielectric strength 15 kV/mm min (ASTM D149), volume resistivity 1 x 10¹⁴ ohm.cm min (ASTM D257)
- Tensile strength 12 N/mm² min, ultimate elongation 350% min (ASTM D638); hardness 45±10 Shore D (ASTM D2240)
- Shrink temperature 125°C, continuous temperature limit -40°C to +110°C (IEC 216)
- Selection chart GRS 130-1 to GRS 130-6
Applications
- Creepage-distance extension on outdoor cable terminations
- Rainy-season tracking prevention on MV terminations
Standards & Compliance
- ASTM D638
- ASTM D792
- ASTM D2240
- ASTM D570
- ASTM D2671
- ESI 09-11
- IEC 216
- ASTM D149
- ASTM D257
- ASTM D150
- ASTM D2303
FAQs
Frequently Asked Questions
What is the Heat Shrink Rain Shed used for?
It is used for:
- Creepage-distance extension on outdoor cable terminations
- Rainy-season tracking prevention on MV terminations
How do I choose the right size?
A heat-shrink part is chosen by two diameters. As supplied (Ds (min)) it must open wider than the largest thing it has to slide over; after shrinking (Df (max)) it must close smaller than the smallest thing it has to grip. Measure both on your cable or busbar and pick the first code in the selection chart that satisfies both.
How is it installed?
Clean and degrease the surface, position the part, then shrink it with a gas torch or a hot-air gun: keep the heat moving round it with a smooth, brushing motion so it recovers evenly without scorching. The instruction sheet in each kit gives the full sequence step by step, including where to start shrinking.
Which standards and test methods are quoted for it?
These, with the values in the Technical Specification on this page:
- ASTM D638
- ASTM D792
- ASTM D2240
- ASTM D570
- ASTM D2671
- ESI 09-11
- IEC 216
- ASTM D149
- ASTM D257
- ASTM D150
Where can I download the datasheet?
From the "Download datasheet" button at the top of this page, or here:
Can I get a quote, a sample or a size that is not listed?
Send your cable details, quantity and application with the "Request a Quote or Sample" form at the foot of this page. For a size or variant that is not in the chart, describe what you need there, or use Technical support at the top of the page, and the technical team will confirm what can be supplied.
47+
Years manufacturing
100+
Countries served
140
Products in range
ISO 9001:2015
Certified & tested