How to Choose the Right Heat Shrink Tubing?

Heat Shrink Tubing is a quite common and convenient tool in our daily life, as it has vast application area, so it is quite important to choose the right heat shrink tubing to do the job. We hope the guide below can help your decision making process.

Step 1 Understand some basic knowledge of heat shrink tubing

Expand Diameter: The minimum inner diameter of heat shrink tubing as manufacturers supply.

Recovered Diameter: The maximum inner diameter of the heat shrink tubing after heated

Recovered Wall Thickness: The minimum tubing outer sheath wall thickness after heated

Shrink Ratio: The maximum tubing diameter can be recovered, compared to the original supplied diameter. Generally speaking, it can be 2:1, 3:1, or 4:1

Shrink Temperature: The minimum Temperature you need to heat the tubing when apply it.

Longitudinal change: There is a slight change of tubing length when heating, usually 5% to 7%.

Step 2 Understand your application circumstances

Tubing diameter requirements

To ensure a robust installation of heat shrink tubing, and best fit to the corresponding substrate, we shall let the tube at least shrink 20% of its supplied diameter. And spare at least 10% of unresolved recovery when the tubing is installed

For example, if the tubing of 2:1 thin wall polyolfin, let’s say at 1” ID, it can recover maximum to 0.50” ID. The applying substrate size better be around 0.55” to 0.80” ID. The reason is, if above 0.80” ID, the tubing might not easy to slide over. If under 0.55”, as the recovered ID it is 0.50”, the insulation property will get affected.

Minimum Wall Thickness requirements

We shall take the Minimum Wall Thickness into consideration, based on the electrical property which the tubing needs to conform.

Electrical Property Requirements

For aerospace, commercial, marine, military or other professional application area, If we need the tubing to provide electrical insulation property, we shall comply with certain industry guidelines or rules.

UL: Underwriters Laboratories

CSA: Canadian Standards Association

ASTM: American Society for Testing and Materials

AMS: Aerospace Material Specification

Just a reminder: For daily home DIY usage, as quite simple, we do not need to consider the above factors.

Working Environment

One another important factor is to understand the working environment, of where the tubing applied. The most determined factors are:

Which temperature will the tubing operate?

Will the tubing contact to acid, diesel, oil, gas, or other chemicals and fluids?

Will it be indoor or outdoor? Is it under heavy sunshine and exposed to UV?

Will it need be buried underground, underwater or use it in telecom towers?

Please contact our product experts for help if you meet critical working environment occasion

Step 3  Choose Suitable Heat Shrink Tubing Material

Once we’ve cleared all of our application requirements and chosen the appropriate tubing dimensions, the next step is how to choose suitable tubing material.

PVC or Polyolefin

Polyolefin type is most widely used heat shrink tubing material, it can be halogen free, operate steadily at high temperature of 125°C-135°C (257°F -275°F).

PVC type cannot withstand such high temperature, usually to 105°C (221°F) or less. However, it has bright colors, and cost is relatively lower than polyolefin

Adhesive Lined Polyolefin

Adhesive lined (dual wall) Polyolefin heat shrink tubing is special made product. The inner adhesive liner can melt and flow when the outer tubing sheath begins to shrink, which offers better sealing, weatherproofing, and insulation property.

Other Tubing formation Materials

Except for the products mentioned above, there are other heat shrink tubing products for specialty use. The list includes:

PTFE Heat Shrink: 2:1 and 4:1 ratio, can operate at 260°C (500°F)

FEP Heat Shrink: 1.3:1 ratio, can operate at 200°C (392°F)

PFA Heat Shrink: 2:1 ratio, can operate at 260°C (500°F)

PVDF Heat Shrink: 2:1 ratio, can operate at 175°C (347°F)

Viton Heat Shrink: 2:1 ratio, can operate at 200°C (392°F)

Diesel Resistant Heat Shrink: 2:1 ratio, can operate at 150°C (302°F)