Semi-Conductive Heat Shrink Tubes For HV Joints & Terminations

Semi-Conductive Heat Shrink Tubes

Semi-conductive heat shrink tubes are used primarily within a wide variety of MV HV heat shrink joints and terminations to provide excellent insulation and sealing properties even when operating in the most severe locations.

Shrink Polymer Systems semi-conductive heat shrink tubes are UV and weather resistant and suitable for up to 33kV/36kV and operating temperatures from -45ºC to +105ºC.

The semi-con heat shrink tubes have a minimum shrink temperature of 100ºC and a minimum full recovery temperature of 120ºC and feature cross-linked polyolefin with excellent electrical and mechanical properties.

Semi-Conductive Heat Shrink Tubes

Product Range

The following table enables the selection of the correct size semi-con heat shrink tubing for medium/high voltage cable joint and termination applications – the heat shrink can be cut to length to suit specific applications. Standard pre-cut length is 1.2m.

Outside diameters from 33-115mm can be accommodated for use with XLPE EPR PILC cable joints and terminations – the semi-conductive heat shrink provides insulation screen on the build-up insulation over cable connectors and cable lugs 11kV/33kV.

Standard colour: Black.

Semi-Conductive Heat Shrink Tube Part Number Heat Shrink Range Total Wall Thickness Length
COT 33-8-1200 8-33mm 2.2mm 1.2m
COT 40-12-1200 12-40mm 2.2mm 1.2m
COT 55-18-1200 18-55mm 2.5mm 1.2m
COT 65-20-1200 20-65mm 2.7mm 1.2m
COT 70-24-1200 24-70mm 2.7mm 1.2m
COT 95-35-1200 35-95mm 3mm 1.2m
COT-115-34-1200 34-115mm 3.2mm 1.2m


Semi-Con Heat Shrink Tubes

Technical Properties

Property Test Method Typical Data
Tensile Strength ASTM D 638 ≥14MPa
Ultimate Elongation ASTM D 638 ≥300%
Longitudinal Shrinkage 0 to ±5%
Volume Resistance IEC 93 <104Ω.cm
Ultimate Elongation After Aging 150, 168 hours ≥200%
Water Absorption ISO 62 <0.15%

Installing Semiconductive Heat Shrink Tubes For MV HV Cable Terminations

Position the semicon stress control tubes onto the MV HV cable ensuring the heat shrink tubing covers the earth connection point and the conductive screen end. However do not extend past this point onto the outer cable sheath. Heat shrink the semicon tubes one at a time starting from the bottom. Ensure the tubes are wrinkle free and have an even wall thickness as per the following excerpt from the installation instruction for 11kV 33kV heat shrink cable terminations.

Semicon Heat Shrink

See how the Cable Jointer Trainer positions the pre-cut length of stress control heat shrink tubing according to the termination kit installation instruction – in this instance single core polymeric 33kV cable. Using a suitable heat source and cable jointers gas torch the installer commences general heating the overall tube to achieve even and consistent shrinking of the tubing surface and then focussing the heat more locally onto the bottom section of the cable close to the semicon screen cut.

The cable preparation process for MV-HV cables is similar for 33kV, 17.5kV, 24kV and 11kV however the heat shrink component sizes and lengths vary across the voltage classes for cable joints and cable terminations.

Cable Terminations 11kV 33kV - Heat Shrink

Watch how to install MV HV Terminations & Joints

HV Terminations, Connectors, Plugs

T&D distribute HV heat shrink, cold shrink and plug-in style cable terminations and connectors for high voltage connection of power cables to air, gas or oil insulated switchgear and transformers, 11kV-33kV.

11kV 33kV Joints Terminations Connectors - 3M Pfisterer Nexans Elastimold

T&D Approved Stockist – 3M, Elastimold, Nexans Euromold & Pfisterer

Data Sheets