Stress Control and Insulation Tubes
C108 Insulation and Stress Control Composite Heat Shrink Tube
A single tube that carries both anti tracking insulation and a zinc oxide stress control sealant for terminations up to 24 kV
- Operating temperature: -55 to 105°C
- Minimum fully recovery temperature: 150°C
- Voltage class: Under 24kV
- Double wall heat shrink
- Insulating layer, stress control sealant layer
- Standard Color: Red
C108 · Stress Control and Insulation Tubes
Product Overview
What C108 Does
Double-wall heat-shrinkable tube structure with an outer layer made of radiation cross-linked polyolefin and a unique zinc oxide stress-control adhesive on the inner layer. Excellent anti-tracking, creepage corrosion resistance, and stress control properties. Suitable for insulation protection of indoor and outdoor power cable termination under 24KV
A single tube that carries both anti tracking insulation and a zinc oxide stress control sealant for terminations up to 24 kV It is manufactured by Dalian United Polymer Material Co., Ltd. in Dalian China where radiation cross linking extrusion and molding are all performed in house under one quality system.
Key Benefits
- Two functions in one part number which cuts kit complexity and installation steps
- Zinc oxide stress control compound that flows and fills at the screen cut back
- Anti tracking and creepage corrosion resistance from the radiation cross linked outer layer
- Suitable for indoor and outdoor terminations up to 24 kV
- Fewer separate shrink operations which shortens the time a crew spends at the work face
Who It Is For
Who Benefits Most from C108
The buyers and site teams this product was designed around
Utilities Standardising on Fewer Part Numbers
One tube replaces the separate stress control tube and insulation tube in a termination which halves the stock lines.
Field Crews Working in Poor Conditions
Fewer separate operations in a trench or on a pole means fewer opportunities for a mistake.
Kit Assemblers Targeting a Lower Part Count
A simpler bill of materials makes a kit cheaper to pack and easier to install.
Distribution Networks up to 24 kV
The composite approach suits the 6 to 24 kV range where a full separate stress control layer is more than the design requires.
Problems It Solves
Problems This Product Removes
Every one of these is a failure mode we have seen on real networks
Two Separate Layers Means Two Chances to Misplace an Overlap
The stress control sealant is bonded to the inside of the insulating tube so the overlap geometry is fixed at the factory.
Stress Control Mastic Is Messy to Apply by Hand
The zinc oxide stress control compound is already positioned as the inner adhesive layer and flows into place when the tube is heated.
Terminations Need to Seal as Well as Insulate
The stress control sealant layer also functions as the adhesive that seals the termination against moisture.
Tracking and Creepage Corrosion Outdoors
The radiation cross linked polyolefin outer layer provides anti tracking and creepage corrosion resistance in the same tube.
Application Scenarios
Where It Is Used
Indoor MV Terminations to 24 kV
Cable box and RMU terminations where space and time are limited.
Outdoor MV Terminations to 24 kV
Pole top terminations where anti tracking is required.
Simplified Kit Designs
Kits built for crews with limited MV jointing experience.
Rapid Restoration Work
Emergency terminations where every reduced step saves outage time.
Training and Qualification
A simpler build sequence for jointers new to MV work.
Technical Data
Specifications and Dimensions
Test methods and requirements taken directly from the manufacturing specification
Technical Data
| Property | Test Method | Requirement |
|---|---|---|
| Outer Layer (Plastic Insulation, red) | ||
| Tensile Strength | ASTM D2671 | ≥8 MPa |
| Ultimate Elongation | ASTM D2671 | ≥200% |
| Heat Aging (136°C/168h) Tensile Strength Ultimate Elongation | ASTM D2671 | ≥8 MPa ≥100% |
| Water absorption (23°C/24h) | ASTM D2671 | ≤0.5% |
| Low-temperature flexibility (-40°C/4h) | ASTM D2671 | No cracking |
| Heat shock (200°C/4h) | ASTM D2671 | No cracking, dripping or flowing |
| Dielectric strength | ASTM D2671 | ≥15 kV/mm |
| Volume resistivity | ASTM D2671 | ≥1.0×1012 Ω·cm |
| Tracking and erosion resistance | ASTM D2303 | After 1hr at 2.5kV, and 1hr at 2.75kV, and 1hr at 3.00kV, and 20mins at 3.25kV. No burn penetration, no sustained burning |
| Flammability | ASTM D2863 | OI ≥25 |
| Color fastness to light | IEC 60684-3 | No visible change |
| Inner layer (Stress control and sealant layer, green) | ||
| Dielectric constant | ASTM D150 | ≥3.1 |
| Volume resistivity | ASTM D2671 | ≥1.0×1011 Ω·cm |
| Note: Use standard samples for testing |
Dimensions
| Size C108 | As supplied(mm) Inner diameter D (min.) | After recovered (mm) Inner diameter d (max.) | Wall thickness t (nom.) | Standard length (m/pcs) |
|---|---|---|---|---|
| 30/12 | 30 | 12 | 5 | ≤ 1.22 |
| 45/15 | 45 | 15 | 5 | ≤ 1.22 |
| 49/16 | 49 | 16 | 5 | ≤ 1.22 |
| 50/20 | 50 | 20 | 5 | ≤ 1.22 |
| 60/28 | 60 | 28 | 5 | ≤ 1.22 |
| 80/35 | 80 | 35 | 5 | ≤ 1.22 |
Manufacturing and Quality
How It Is Made and Checked
Compounding extrusion radiation cross linking expansion and test all under one roof in Dalian
-
01
Compounding
Base polyolefin antioxidants flame retardants and functional fillers are mixed to a recipe held under our own formulation control rather than bought as a masterbatch.
-
02
Extrusion
The compound is extruded to the required wall and diameter. Co extruded products form two or three layers in a single pass so no interface can trap air.
-
03
Radiation Cross Linking
Electron beam irradiation creates the cross linked network that gives the material its shape memory. This step is what makes the product heat shrinkable.
-
04
Expansion
The cross linked part is heated expanded to its supplied diameter and cooled under tension so the expanded shape is locked in until heat is applied again.
-
05
Test and Inspection
More than 90 percent of product performance tests are carried out in our own laboratory including tensile elongation heat aging dielectric strength and tracking resistance.
-
06
Packing and Traceability
Each batch carries a production record so a delivered part can be traced back to its compound lot and process parameters.
Certification
ISO 9001:2015
Quality management system
IATF 16949:2016
Automotive quality management
ISO 14001:2015
Environmental management
ISO 45001:2018
Occupational health and safety
GJB 9001C-2017
Defence quality management
UL 224 E341796
Extruded insulating tubing
CE / RoHS
European conformity and restricted substances
CCS / ABS / DNV
Marine classification society approvals
Comparison
How C108 Compares
An honest comparison so you can rule this product in or out quickly
| Approach | Part Count | Steps at the Work Face | Voltage Reach |
|---|---|---|---|
| C108 composite tube | One | One shrink operation | Up to 24 kV |
| C102 plus C101 separately | Two | Two shrink operations | Up to 36 kV |
| Stress control mastic plus tube | Two | Hand build plus shrink | Up to 36 kV |
Use Guide
How to Select and Install C108
The sequence our engineers walk customers through on every first installation
-
01
Confirm the Voltage Class
C108 is rated up to 24 kV. Above 24 kV use a separate C102-35 stress control tube with C101 insulation.
-
02
Prepare a Clean Square Screen Edge
The stress control sealant needs a clean edge to flow against.
-
03
Set the Overlap Onto the Screen
Position the tube so the inner sealant layer overlaps the metallic screen by the distance in the kit drawing.
-
04
Heat from the Screen End First
Start at the screen end so the sealant flows into the step and drives air toward the open end.
-
05
Watch for Sealant Flow
A visible bead of stress control sealant at the screen edge confirms the layer has flowed into position.
-
06
Complete the Termination
Add rain sheds outdoors and complete the screen earth connection and end seal.
FAQ
C108 Frequently Asked Questions
The questions buyers ask before they place an order
What is the zinc oxide layer for
Can C108 replace a separate stress control tube
Does it seal as well as insulate
Is it suitable outdoors
What recovery temperature is required
How many sizes are offered
Still need an answer ask our engineers on WhatsApp
Related
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MV Kits 8.7/15 kV
Indoor outdoor and joint kits for 8.7/15 (17.5) kV single core and three core cable tested to IEC 60502-4
VIEW DETAILSGet a Quotation for C108
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