Medium Wall Heat Shrink Tube for LV Cable Joints (GMW)

About Medium Wall Heat Shrink Tube for LV Cable Joints (GMW)

GMW is Gala's medium-wall heat-shrink tube, sold under the INSULTUBE name. It is a cross-linked polyolefin tube supplied in its expanded state; heated to about 125 deg C it recovers tightly onto whatever it covers. The compound contains carbon black to protect it from sunlight.

Its main job is on low-voltage cable work: insulating the crimped connectors of LV straight-through joints and protecting LV cable terminations against moisture and dirt. Because it comes in 25 sizes, from GMW 10/3 up to GMW 425/120, the same product also serves for cable jacket repair, sealing splices, insulating long connections and general mechanical protection of cables and pipes. An optional hot-melt adhesive lining turns it into a sealed, moisture-blocking cover.

Choosing a size is simple. The code gives two diameters: the first is the minimum inside diameter as supplied, which must slip over the largest part of the job; the second is the maximum inside diameter after free recovery, which must be smaller than the smallest part so the tube grips. Order as code, size and length in mm, for example GMW 10/3 1000. Cut lengths go up to 1200 mm on most sizes.

Installation: slide the tube onto the cable before making the joint, crimp the connector, position the tube centrally and shrink it with a propane torch on a soft blue flame, working from the middle outwards. With the adhesive version, a small bead of adhesive at both ends shows the seal is complete.

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

Specifications

• Brand: Gala
• Product type: Medium wall heat shrink tube
• Material: Cross-linked polyolefin, carbon black UV protected
• Colour: Black (other colours on request)
• Voltage rating: LV cable joints and terminations up to 3.3 kV (GSF rating, Feb 2025 sheet)
• Operating temperature: -40 deg C to +110 deg C continuous
• Shrink ratio: About 3:1 to 3.8:1 depending on size (supplied ID / recovered ID)
• Size range: 10 mm to 425 mm supplied ID; 3 mm to 120 mm recovered ID
• Wall type / thickness: Medium wall, 1.5 mm to 3.5 mm after recovery (+/-10%)
• Adhesive / sealant: Optional hot-melt adhesive lining
• Standards tested to: Test methods quoted on GSF's datasheet - ASTM D638, ASTM D2671, ASTM D149, ASTM D257
• Application: Insulation and environmental protection of LV cable joints, connectors and terminations; cable jacket repair
• Installation: Propane torch, soft blue flame, shrink from the centre outwards
• Country of origin: India
• Shrink temperature: 125 deg C
• Tensile strength: 12 N/mm2 min (ASTM D638)
• Elongation at break: 350% min
• Dielectric strength: 12 kV/mm min on 2 mm wall (ASTM D149)
• Volume resistivity: 1 x 1012 ohm.cm min (ASTM D257)
• Water absorption: 0.5% max
• Maximum cut length: 1200 mm up to 250/70; 1000 mm for 320/90; 500 mm for 375/110 and above
• Ordering format: code + size + length in mm, e.g. GMW 10/3 1000

Sizes

• GMW 10/3 | D 10 / d 3 | T 1.5 mm
• GMW 12/4 | D 12 / d 4 | T 1.8 mm
• GMW 16/5 | D 16 / d 5 | T 2.0 mm
• GMW 19/6 | D 19 / d 6 | T 2.0 mm
• GMW 22/6 | D 22 / d 6 | T 2.3 mm
• GMW 25/8 | D 25 / d 8 | T 2.5 mm
• GMW 30/8 | D 30 / d 8 | T 2.6 mm
• GMW 33/10 | D 33 / d 10 | T 2.6 mm
• GMW 40/12 | D 40 / d 12 | T 2.7 mm
• GMW 50/16 | D 50 / d 16 | T 2.7 mm
• GMW 65/19 | D 65 / d 19 | T 2.7 mm
• GMW 70/22 | D 70 / d 22 | T 2.7 mm
• GMW 75/22 | D 75 / d 22 | T 2.7 mm
• GMW 95/25 | D 95 / d 25 | T 3.0 mm
• GMW 105/30 | D 105 / d 30 | T 3.0 mm
• GMW 115/34 | D 115 / d 34 | T 3.2 mm
• GMW 130/36 | D 130 / d 36 | T 3.2 mm
• GMW 140/42 | D 140 / d 42 | T 3.2 mm
• GMW 160/50 | D 160 / d 50 | T 3.3 mm
• GMW 180/55 | D 180 / d 55 | T 3.3 mm
• GMW 200/60 | D 200 / d 60 | T 3.5 mm
• GMW 250/70 | D 250 / d 70 | T 3.5 mm
• GMW 320/90 | D 320 / d 90 | T 3.5 mm
• GMW 375/110 | D 375 / d 110 | T 3.5 mm
• GMW 425/120 | D 425 / d 120 | T 3.5 mm

Applications: Electricity distribution utilities, cable jointing contractors, cable manufacturers (jacket repair), panel and capacitor-bank builders, railways, telecom and CATV, oil and gas, marine and offshore, industrial plant maintenance