The increasing numbers of engineers and consultants have accepted the effectiveness of heat shrink technology to secure electrical installations; they are in favor of embracing heat shrink tubes at least in middle to large electrical installations. When the manufacturers of heat shrink sleeves are expanding their product line to facilitate the users, the first time users still have some clouds over their inclination towards using heat shrink tubes or sleeves. The success of getting the ultimate results as you expect by using the most advanced electrical insulation technology depends upon choosing the right shrink ratio, diameter, & length of heat shrink tubes or sleeves.

Shrink Ratio of Heat Shrink Tubes: Heat shrink tubes are manufactured to give 2:1 or 3:1 shrink ratios. It means the heat shrink tube expands two or three times on being heated. When the tubes are shrunk, it is considered in the recovered state. The 2:1 shrink ratio of heat shrink tubes is good for jacketing wire bundles or harnesses. The 3:1 ratio is good to seal irregular shapes. Both the heat shrink tubes of2:1 and 3:1 shrink ratios are available in single wall tubing and dual wall tubing structures.

Diameter of Heat Shrink Sleeves: The ideal recovered diameter of the underlying cables should be measured at the widest part. The ideal heat shrink tubes would be of 20% – 30% larger diameter. The internal and outer diameters are listed in the data sheets; you should focus more on the internal diameter of heat shrink tubes to get the best fit insulation solution.

Length of Heat Shrink Tubes: The length of heat shrink tubes is associated with longitudinal shrinkage. Heat shrinkable sleeves shrink in length also during the recovery process. Focus on the change in length after recovery stage. Longitudinal shrinkage in heat shrink sleeves varies from 5% to 10%; and, it depends upon the tube material.

Which heat shrink tubing should you choose- Single Wall vs. Dual Wall Tubing:  The heat shrink tubes are being used to address multiple diverse concerns like strain relief, insulation, cosmetic, sealing, and protection. Dual wall shrink tubes work for all of these concerns but using these cables everywhere while neglecting the suitability of single wall shrink tubes may be overkill because of cost factors.

Most single-wall heat shrink tubes are made of polyolefin; this cross-linked material has a shrink temperature of 100°C and can withstand temperatures up to 125°C-135°C. The most common shrink ratio for polyolefin single wall heat shrink tubes is 2:1 but these are made available in 3:1 and 4:1 ratios also if a customer demands. Dual wall heat shrink tubes are used to get protection against the continuous presence of moisture. Dual wall heat shrink sleeves provide extra sealing to prevent chemicals, fluids, and water to erode your connections. Dual wall tubes are made of two different layers- the outer layer is of cross-linked polyolefin and the inside layer is of an adhesive that melts on being heated.

Pro-tip: When you decide to use heat shrink tubes to insulate and secure your electrical installations in the best possible way, also use other heat shrink insulation accessories to insulate poles, switchgear, busbars, etc.

Cold shrink and heat shrink tubes look identical when you see them at the surface but the internal characteristics are too different. Cold shrink and heat shrink tubes have different insulation mechanisms because of different properties; therefore, these are used in different applications. The tubing is used in an increasing range of applications in different business sectors; the usage is not limited just to insulation, splicing, environmental sealing, terminating, etc. Heat shrink and cold shrink tubes and accessories are more cost-effective to be used in harsh environments than using other tubing types. A thin separation line exists between heat shrink and cold shrink tubes; the major difference we see in the way of application of both.

Heat shrink tubes come pre-stretched. Heat shrink tubes need a heat source for tight-fit installation and can’t be installed without a heat gun. On being heated, the polyolefin heat shrink cable tubing shrinks to its original size to create a tight-fit seal on the cable joint. The polyolefin material used in heat shrink tubes is highly resistant to chemicals, gases, and water because it becomes extremely ridged after heating. Heat shrink tubes are preferred because of getting mechanical protection also. Heat shrinks tubes are finding increasing applications in industrial and commercial installations in low-temperature areas where the presence of chemical gases is high in the environment. The prominent heat shrink tubes manufacturers supply and export different types of heat shrink tubes made of-

• Polyolefin
• PTFE (Polytetrafluoroethylene)
• FEP (Fluorinated ethylene propylene)
• PVDF (Polyvinylidene fluoride)
• Elastomeric
• Silicone

Cold shrink tubes are made of silicone rubber. These are made available in stretched form with a removable plastic core that facilitates for easy mobility. After the placement of cold shrink tubes over the cable joints or cable terminations, the inner cover is pulled out allowing the tube to contract up to its pre-stretched size and to deliver a long-term effective sealing of the joint. Cold shrink tubes are a better option to protect XLPE cable insulation against overheating. Cold shrink tubes also benefit the users because you don’t need an ideal time for cooling before energizing the cables. Cold shrink tubes create a static and stable seal over the joints that don’t expand or contract. Typical applications of cold shrink tubes include – Sub-Bottom Profiling, Sidescan Sonars, underwater camera systems, data telemetry systems, digital video recorders, electric survey winches, marine pumps, underwater trenching machines, etc.

Heat Shrink Vs Cold Shrink at a Glance:

How To Buy The Best Suitable Cable Insulation Tubes:

Now you are well familiar with which type of cable Insulation shrink tube is good for you in a particular environment. Your next concern would be to buy the cable Insulation shrink tube in a hassle-free manner assuring for the robust protection to justify your decision. Here, I would like to recommend you Gala Thermo to buy heat shrink tubes with complete assistance. To buy cold shrink cable insulation tubes, you can approach the top manufacturers like YamunaPower, Thorne & Derrick, Shripat Tech, etc.