Product Description
Heat Shrink Protective Tube
The heat shrink protective tube is a heavy-wall, cross-linked polyolefin sleeve that does the everyday workhorse job in a cable system: it insulates, seals against moisture and mechanically armours the parts of a joint, termination, busbar or conductor that must survive abrasion, chemicals and the weather. Supplied as standard adhesive-lined at both ends, it recovers to a tight, void-free sheath that grips the substrate and locks water out of the joint.
Where the rest of the family is engineered for one specific electrical duty, this tube is built for protection and sealing across the widest size range we offer - from a 10 mm control core up to a 300 mm large-diameter cable, busbar or pipe. Use it as electrical insulation on 1 kV cable joints and terminations (Φ50 and below), or as the outer sealing and mechanical protection layer for power cable joints up to 42 kV.
Manufactured from radiation cross-linked polyolefin, it is supplied in black, red, yellow, blue and green (Φ50 and below; black only above Φ50) - so a single product also handles phase identification and colour coding. Other colours are available on request.
Why a protective / sealing tube is a separate product
Not every sleeve in a cable system is there to grade the electric field. Most of the tubing on a joint or termination is there to keep water out, keep the joint mechanically sound and hold the assembly together through years of outdoor service. That is a different job from tracking resistance or stress control, and it calls for a different tube: a heavy-wall, adhesive-lined sleeve that seals at both ends and shrugs off abrasion and chemicals.
Two failure modes drive the specification:
Moisture ingress. A joint that is not sealed at both ends wicks water along the cable core; the moisture then attacks the insulation interface and corrodes the conductor.
Mechanical and chemical damage. Buried, ducted, or outdoor cables are exposed to abrasion, soil chemicals, oil and sunlight; an unarmoured joint jacket is the first thing to fail.
The adhesive-lined heat shrink protective tube closes both routes at once. The hot-melt adhesive on the inner wall melts during recovery, fills the profile of the substrate and forms a watertight seal at both ends - and the recovered cross-linked polyolefin wall provides the abrasion and chemical resistance. Tubes coated with adhesive along the full length are available for the highest sealing requirement.
One tube, two duties. Up to Φ50 it is specified as a 1 kV insulating sleeve for LV joints and terminations. On larger conductors and on MV joints it is specified as the outer sealing / protection layer - a jacket-restoration sleeve rated to survive the environment of a 42 kV joint. The electrical data below (≥ 15 kV/mm, ≥ 1×10¹¹ Ω·cm) reflects this protective role, not a primary MV-insulation duty.
Key features & benefits
Adhesive-lined at both ends - hot-melt seal on both cut faces, blocking moisture ingress at each end of the joint; full-length adhesive coating available on request.
Widest diameter range in the family - 18 standard specs from WRSHG-10/5 up to WRSHG-300/100, covering cores, cables, busbars and pipes from Φ10 to Φ300 mm as supplied.
Colour-coded selection - black, red, yellow, blue and green (Φ50 and below); other colours on request. Ideal for phase identification and circuit coding.
Outstanding abrasion & chemical resistance - protects joints in buried, ducted and outdoor service.
Dual electrical duty - 1 kV insulation for cable joints and terminations (Φ50 and below); outer sealing / protection for power cable joints up to 42 kV.
Strong, tough wall - tensile strength ≥ 12 MPa, elongation at break ≥ 300 %.
Reliable dielectric data - dielectric strength ≥ 15 kV/mm; volume resistivity ≥ 1×10¹¹ Ω·cm.
Stable in service - heat shock 160 °C / 4 h with no cracking; brittle temperature −40 °C; water absorption ≤ 0.1 % (23 °C, 24 h).
Low longitudinal shrinkage (≤ 5 %) - the tube stays where it is placed and does not pull back off the joint.
Controlled recovery - begins shrinking at 90 °C and is fully recovered at 130 °C.
Applications
1 kV cable joints and terminations - electrical insulation over LV cores, lugs and connections (Φ50 and below)
Outer sealing protection of power cable joints up to 42 kV - jacket restoration / environmental seal
Colour-coded phase identification - red / yellow / blue / green sleeves on LV phase conductors
Busbar and conductor protection - abrasion and chemical guarding on copper and aluminium bars
Cable jacket repair and reinforcement - sheath rebuilding on damaged or spliced cable
Buried, ducted and outdoor cable runs - moisture and soil-chemical protection
Pipes, rods and cylindrical parts - general anti-corrosion and anti-abrasion wrapping
How this tube differs from the rest of the heat-shrink family
| Tube | Function | Electrical role | Colour | Size coverage | Adhesive |
|---|---|---|---|---|---|
| WRSHG - Heat Shrink Protective Tube (this page) | Insulation + sealing + mechanical/chemical protection | 1 kV insulation (≤ Φ50); outer sealing up to 42 kV | Black, red, yellow, blue, green (≤ Φ50); black above | Φ10–300 mm (18 specs) | Both ends (full-length on request) |
| WRSJG - Anti-Tracking Insulation Tube | Anti-tracking / anti-flashover | MV insulation; tracking resistance IEC 60587 (1A 3.5) | Red | Φ30–100 mm (14 specs) | One end |
| WDWT - Semi-conductive Dual Layer Tube | Insulation + electrical shielding / stress control | MV joints; semi-conductive outer layer (≥ 1×10¹⁰ Ω·cm) | Red inner + black outer | Φ30–120 mm (8 specs) | Adhesive-free |
In short: choose WRSHG when the job is to protect and seal - LV insulation, joint outer sealing, abrasion and chemical armouring, phase coding - and above all when you need a large diameter up to 300 mm or a watertight seal at both ends. Choose WRSJG for anti-tracking on MV terminations and busbars, and WDWT when you must re-establish electrical shielding / stress control across a cut-back screen.
Technical specifications
Selection table - standard sizes
| Spec. | As supplied ID min (mm) | Wall (±0.2 mm) | Recovered ID max (mm) | Recovered wall (±0.3 mm) | Standard cut length (mm) | Continuous length (m/roll) |
|---|---|---|---|---|---|---|
| WRSHG-10/5 | 10 | 0.5 | 5 | 1.1 | 275–1000 | 25 |
| WRSHG-15/7 | 15 | 0.5 | 7 | 1.1 | 275–1000 | 25 |
| WRSHG-20/9 | 20 | 0.6 | 9 | 1.5 | 275–1000 | 25 |
| WRSHG-30/11 | 30 | 0.7 | 11 | 1.6 | 275–1000 | 25 |
| WRSHG-35/13 | 35 | 0.7 | 13 | 1.8 | 275–1000 | 25 |
| WRSHG-45/17 | 45 | 0.8 | 17 | 2.0 | 275–1000 | 25 |
| WRSHG-50/23 | 50 | 1.1 | 23 | 2.5 | 800–1200 | 25 |
| WRSHG-60/23 | 60 | 1.0 | 23 | 2.5 | 800–1200 | 25 |
| WRSHG-85/30 | 85 | 1.0 | 30 | 2.8 | 800–1200 | 25 |
| WRSHG-100/39 | 100 | 1.1 | 39 | 3.0 | 800–1200 | 15 |
| WRSHG-120/45 | 120 | 1.1 | 45 | 3.0 | 800–1200 | 15 |
| WRSHG-140/49 | 140 | 1.2 | 49 | 3.6 | 800–1200 | 15 |
| WRSHG-160/57 | 160 | 1.2 | 57 | 3.6 | 800–1200 | - |
| WRSHG-180/61 | 180 | 1.3 | 61 | 4.0 | 800–1200 | - |
| WRSHG-200/70 | 200 | 1.5 | 70 | 4.4 | 800–1200 | - |
| WRSHG-230/72 | 220 | 1.4 | 72 | 4.4 | 800–1200 | - |
| WRSHG-250/87 | 250 | 1.6 | 87 | 4.4 | 800–1200 | - |
| WRSHG-300/100 | 290 | 1.4 | 100 | 4.4 | 800–1200 | - |
Colour options: black, red, yellow, blue, green up to Φ50; black only above Φ50. Other colours on request.
Technical data
| Property | Test method | Standard value |
|---|---|---|
| Tensile strength | ASTM D-638 | ≥ 12 MPa |
| Elongation at break | ASTM D-638 | ≥ 300 % |
| Volume resistivity | IEC 60093 | ≥ 1×10¹¹ Ω·cm |
| Dielectric strength | IEC 60243 | ≥ 15 kV/mm |
| Brittle temperature | ISO 974 | −40 °C |
| Heat shock | 160 °C, 4 h | No crack |
| Water absorption (23 ± 2) °C, 24 h | ISO 62 | ≤ 0.1 % |
| Hardness (Shore A) | ISO 868 | ≥ 80 |
| Longitudinal shrinkage | ASTM D-2671 | ≤ 5 % |
| Eccentricity | ASTM D-2671 | ≤ 35 % (Φ200 and below); ≤ 55 % (above Φ200) |
How to select the right size
Measure the substrate OD - the diameter of the cable core, lug, busbar or pipe to be covered.
Pick by recovered ID - the recovered inner diameter must be smaller than the substrate OD so the tube grips and seals. Example: a 23 mm core → choose WRSHG-50/23 (as supplied 50 mm, recovers to 23 mm).
Check the as-supplied ID - the tube must slide over the largest part of the joint before shrinking (50 mm for a WRSHG-50/23).
Confirm the duty - for LV insulation up to 1 kV keep to the smaller sizes (Φ50 and below, where colour options are widest); for outer sealing / protection on larger conductors or MV joints, use the wall thickness of the larger specs.
Choose length and colour - standard cut lengths are 275–1000 mm for the small specs and 800–1200 mm from WRSHG-50/23 upward; continuous rolls are supplied at 25 m (small specs) or 15 m (WRSHG-100/39 to WRSHG-140/49). Select the colour per your phase-coding scheme.
Not sure of the size? Send us the cable or busbar OD and the service voltage - we will recommend the correct WRSHG spec.
Product display
Certificate
FAQ
Q: What is a heat shrink protective tube used for?
A: It insulates, seals and mechanically protects cable joints, terminations, busbars and conductors. It provides electrical insulation on 1 kV joints and terminations (Φ50 and below), and outer sealing protection for power cable joints up to 42 kV, with abrasion and chemical resistance for buried and outdoor service.
Q: How is it different from an anti-tracking or a semi-conductive heat shrink tube?
A: It is the general protective / sealing sleeve. Anti-tracking tubing (WRSJG) resists surface tracking on MV terminations; semi-conductive dual-layer tubing (WDWT) restores electrical shielding and stress control across a cut-back screen. This protective tube is the one to specify when the job is to insulate, seal and armour - and it covers a far wider diameter range.
Q: Where is the adhesive - one end or both?
A: As standard the tube is adhesive-lined at both ends, giving a watertight seal at each end of the joint. Full-length adhesive coating is available upon customer request.
Q: What sizes are available?
A: 18 standard specs from WRSHG-10/5 (as supplied 10 mm, recovers to 5 mm ID) up to WRSHG-300/100 (as supplied 290 mm, recovers to 100 mm ID) - the widest diameter range in the range.
Q: What colours can I order?
A: Black, red, yellow, blue and green for Φ50 and below; black only above Φ50. Other colours are available upon request. The colour options make it easy to use the tube for phase identification.
Q: What is the shrink temperature?
A: Shrinking starts at 90 °C and the tube is fully recovered at 130 °C.
Q: What voltage does it suit?
A: Two roles: 1 kV electrical insulation for cable joints and terminations up to Φ50, and outer sealing / protection of power cable joints up to 42 kV. The technical data reflect its protective duty (dielectric strength ≥ 15 kV/mm, volume resistivity ≥ 1×10¹¹ Ω·cm).
Q: How is it supplied?
A: Standard cut lengths 275–1000 mm (small specs) or 800–1200 mm (WRSHG-50/23 and larger), and continuous rolls of 25 m or 15 m depending on spec. Custom lengths and colours on request.
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