Red Heat Shrink Insulation Tube for MV Cable Joints (GRT)

About Red Heat Shrink Insulation Tube for MV Cable Joints (GRT)

INSULTUBE Red, Gala code GRT, is a red cross-linked polyolefin heat-shrink tube made to insulate the connector area of medium-voltage power cable joints. In a heat-shrink joint it is shrunk over the jointed conductors and stress-control layer to build up the insulation, before the outer layers go on. The red colour makes the insulating layer easy to identify during jointing and inspection.

The tube comes in three wall grades on the same diameters, so the jointer can build the insulation thickness the joint needs: standard GRT with a 2.6 to 3.2 mm recovered wall, heavy-wall GRT(HW) at 3.0 to 4.0 mm, and extra-heavy-wall GRT(EHW) at 6.2 mm. Sizes run from 30/8 to 130/36 (EHW from 50/16); the first figure is the minimum supplied inside diameter, the second the maximum recovered inside diameter.

The material shrinks at 125 deg C and is rated for continuous use from -40 deg C to +110 deg C. GSF's datasheet guarantees a tensile strength of at least 12 N/mm2 and elongation of at least 300 percent. Custom dimensions, wall thicknesses, lengths and colours can be made on request.

GRT is mostly bought by cable jointers and by makers of heat-shrink joint kits who assemble their own components.

Manufactured by Gala in India. Datasheet and size selection on request.

Specifications

• Brand: Gala
• Product type: Heat shrink insulation tube for cable joints, red
• Material: Cross-linked polyolefin
• Colour: Red
• Operating temperature: -40 deg C to +110 deg C continuous
• Size range: 30 mm to 130 mm supplied ID; 8 mm to 36 mm recovered ID
• Wall type / thickness: GRT 2.6 to 3.2 mm; GRT(HW) 3.0 to 4.0 mm; GRT(EHW) 6.2 mm (after recovery, +/-10%)
• Standards tested to: Test methods quoted on GSF's datasheet - ASTM D638, ASTM D2671, ASTM D2240, ASTM D570, ASTM D150
• Application: Insulating layer in medium-voltage power cable joints
• Installation: Heat-shrunk with a gas torch as part of the joint build-up
• Country of origin: India
• Shrink temperature: 125 deg C
• Tensile strength: 12 N/mm2 min (ASTM D638)
• Elongation at break: 300% min
• Hardness: 45 +/- 10 Shore D
• Water absorption: 0.2% max
• Thermal ageing: after 120 deg C for 500 h, tensile 11 N/mm2 min and elongation 250% min
• Low temperature flexibility: -40 deg C for 4 h, no cracking
• Heat shock: 250 deg C for 30 min, no cracking or flowing
• Dielectric constant: 5 max

Sizes

• 30/8 | D 30 / d 8 | GRT 2.6 | GRT(HW) 3.0 | EHW -
• 33/10 | D 33 / d 10 | GRT 2.6 | GRT(HW) 3.0 | EHW -
• 40/12 | D 40 / d 12 | GRT 2.7 | GRT(HW) 4.0 | EHW -
• 50/16 | D 50 / d 16 | GRT 2.7 | GRT(HW) 4.0 | GRT(EHW) 6.2
• 70/22 | D 70 / d 22 | GRT 2.7 | GRT(HW) 4.0 | GRT(EHW) 6.2
• 95/25 | D 95 / d 25 | GRT 3.0 | GRT(HW) 4.0 | GRT(EHW) 6.2
• 105/30 | D 105 / d 30 | GRT 3.0 | GRT(HW) 4.0 | GRT(EHW) 6.2
• 115/34 | D 115 / d 34 | GRT 3.2 | GRT(HW) 4.0 | GRT(EHW) 6.2
• 130/36 | D 130 / d 36 | GRT 3.2 | GRT(HW) 4.0 | GRT(EHW) 6.2
• Order as code and size, e.g. GRT 50/16, GRT(HW) 50/16, GRT(EHW) 50/16.

Applications: Cable jointing contractors, heat-shrink joint kit makers, power distribution utilities, cable manufacturers, industrial and infrastructure electrical contractors