Choosing the Right Tubing; A Simple Guide

Correct tubing selection is crucial to ensure a system’s proper performance, whether it is in industrial processes, medical devices, pneumatic systems, or fluid transport. In other words, the reliability of the system’s applications depends heavily on choosing the right tubing.

Tubes come in various sizes, materials, and other specifications. So, it can be overwhelming if you want to choose tubing without a good guideline. But by considering a few factors before selecting tubing for a system, you can come to an appropriate decision.

In this article, we will introduce these key factors and provide simple tubing tips. At the end, we will answer some of the common questions regarding tubing selection.

Key Factors to Consider When Choosing the Right Tubing

Apart from the wide range of tubing, each system’s requirements and conditions also play a significant role in appropriate tubing selection.

Choosing the right tubing is vitally important for different reasons. Some of them include

• Safety: Choosing the wrong tubing can lead to safety issues and hazards that threaten the people and the surrounding environment.
• Efficiency: The proper tubing ensures the system’s efficiency and reliable performance.
• Avoiding issues: Wrong tubing can lead to leakage, contamination, chemical reactions, ruptures, and failures. Generally, it can compromise the integrity of the system.
• System longevity: The right tubing is durable, resistant to corrosion, compatible, and protects the system from wear and tear. As a result, it becomes low-maintenance and can operate for a long time without issues. 
• Cost implications: The need for frequent replacements, repairs, and maintenance is a consequence of using the wrong tubing, which can cost a lot.

Therefore, for safe and optimal performance of the system, make sure you consider the factors and tips below before selecting the tubing.

1. Make Sure of Material Compatibility

Each system carries a certain type of substance that might be corrosive, high or low in temperature, and cause chemical reactions.

On the other hand, tubing is made of various materials with different levels of resistance to temperature, corrosion, chemicals, and other environmental conditions. These materials include

• stainless steel tubing,
• copper tubing,
• PVC tubing,
• rubber tubing,
• glass tubing,
• polyethylene tubing,
  and more.

Therefore, the tubing used in each system must be compatible with its unique conditions and applications.

For example, although rubber tubing is resistant to chemicals, it can melt in high temperatures or lose its mechanical properties in extremely low temperatures.

As a result, make sure your choice of tubing is compatible with the system. Consider 

• Chemical compatibility: Tubing materials have varying levels of resistance to chemicals, acids, oils, solvents, fuels, etc. If the tubing material is not compatible with the substances it comes in contact with, there will be degradation, contamination, leakage, and failure.
• Temperature compatibility: Each tubing material has a temperature limit. To make sure the tubing can operate safely, assess the temperature range of your application and choose a tubing material that withstands the system’s temperature.
• Environmental compatibility: Where is the system located? Will the tubing be exposed to direct sunlight, humidity and moisture, and other outdoor elements? Some tubing materials, such as PTFE (Teflon), PFA, and FEP tubing, are specially formulated to resist environmental degradation. For others, you might be able to make them more compatible by using additional protection, such as painted or galvanized tubing.

Corrosiveness: Stainless steel tubing, titanium tubing, and some other types of tubing are famous for their resistance to corrosion.

2. Understand the Application Requirements

Think carefully about your application requirements because choosing the right tubing depends a lot on these factors. Consider

• Pressure rating: The tubing material’s strength and wall thickness determine its maximum working pressure (or burst pressure). This pressure rating provides the necessary information for how much pressure the tubing can tolerate without causing safety issues or damage. Select a type of tubing that can withstand your system’s pressure.

• Flexibility: In some applications, there is a need for highly flexible tubing, for example, in tight bends. While in some others, the tubing must be rigid to ensure stability. To make a proper tubing selection, take the tubing’s resistance to impact, kinking, and wear and tear into account.

• Electrical conductivity and insulation: In electrical and electronic applications, for grounding or shielding purposes, the tubing must allow the passage of the electrical current. In other words, it should be conductive. For example, copper tubing. On the other hand, some applications require tubing materials that have electrical insulation properties, such as silicon tubing and fluoropolymer tubing (PTFE, PFA, FEP), to avoid short circuits or electrical leakage. Other types of tubing can be plated with nickel or chrome to add some electrical insulation properties.

• Sterilization: For medical, pharmaceutical, and some other applications, the tubing must withstand the sterilization processes that can involve gamma irradiation, autoclaving, ethylene oxide sterilization, and/or electron beam. Polypropylene tubing, PTFE, and some grades of silicone tubing might be good choices.

• Transparency: For some purposes, such as laboratory equipment and medical devices, it is necessary to monitor the flow of the fluids (liquid or gas). So, transparent tubing, such as clear PVC or glass tubing, makes quality control, measurement, and inspection of the fluid transport easy.

Temperature range and environmental conditions (they were discussed in the previous section.).

3. Select the Right Tubing Size

Tubing size refers to the following dimensions:

• ID or inner diameter: This measurement shows how big is the hollow space inside the tubing. The larger the ID, the greater the flow.
• OD or outer diameter: This refers to the total width of a tube which includes the hollow space as well as the thickness of the walls. Knowing the exact OD is essential in determining the tubing compatibility with other components of a system, like connectors and fittings.
• Wall thickness: Another important measurement in tubing is how thick the walls are. This normally shows how strong, durable, and flexible the tubing can be. Therefore, thicker walls offer greater strength and higher pressure ratings, while thinner walls offer more flexibility.

To be compatible and interchangeable, tubing must follow the American National Pipe Thread (NPT) standards and the International Organization for Standardization (ISO) metric system.

Now, choosing the right tubing size depends on factors such as the system’s:

• flow rate,
• pressure requirements,
• other components size (the tubing size must match the connectors, fittings, etc.).

4. Comply with Regulatory Requirements and Safety Standards

Except for the standardized tubing sizes, for each industry and application, there might be some regulatory requirements and safety standards that you must comply with. For example,

• Food-grade standards, such as FDA (Food and Drug Administration) and NSF (National Sanitation Foundation),
• For electrical and fire safety standards, like UL (Underwriters Laboratories) and RoHS (Restriction of Hazardous Substances),
• For chemical-grade and other safety standards, like ASTM (American Society for Testing and Materials) and ISO.

For some industries, it is also necessary for tubing materials to meet some environmental standards to promote recycling, reduce waste, and restrict the use of hazardous substances.

5. Consider the Cost and Availability of the Tubing

Depending on the material, manufacturing process, availability, and application requirements, the cost of tubing can vary. For example, PTFE tubing can be considered an expensive choice because it offers unique properties that make it a suitable choice for many demanding applications.

Therefore, before making the final decision, you should also consider the project budget.

Another important factor that can affect the future of the system is the availability of the type of tubing you choose. If it is hard to find in the market, you will face difficulties when it comes to replacements in the future.

6. Evaluate the Lifespan and Maintenance Requirements

How long do you expect the tubing to work properly? Consider the lifespan of the tubing as well as its maintenance requirements. See if you can keep up with the frequent cleaning and maintenance that some materials need.

Overall, choosing the right tubing is a decision that must be taken after a careful assessment of different aspects of the system, industry standards, your budget, and its maintenance requirements. Consulting with professionals will save you a lot of headaches.

Do you have a hard time deciding the budget? Call to get a quote.

FAQs About Choosing the Right Tubing

There are a few questions that we get from our customers all the time. Here, we will answer some of these FAQs about choosing the right tubing.

What Tubing Material Is Best for High-Temperature Applications?

For higher temperatures, you should consider the temperature limits and the thermal stability of the tubing. But generally, stainless steel tubing and PTFE tubing are among the materials with the greatest resistance to high temperatures.

Is It Possible to Use the Same Tubing Material for Both Gas and Liquid?

The short answer is yes. However, although most materials can be used to carry both gas and liquid, some of them can be better suited for only one of them. For example, materials, such as PVC tubing and stainless steel tubing, that are non-porous and have a smooth surface, are better choices for liquid transport.

To ensure the right tubing selection, consider the following factors.

• Pressure ratings,
• Permeability (to prevent the loss of gas, lower permeability is more desirable.),
• Characteristics of the flow (such as the flow rate, pressure drop, consistency of the flow, turbulence, etc.).

What Happens If the Connectors and Fittings Material Is Not the Same as the Tubing Material?

If the materials of the tubing and other components are not the same, they cannot be properly sealed and the strength of the connection will be compromised. Following the manufacturer’s instructions is recommended to ensure compatibility.

What Factors Should I Consider for Tubing Used in Outdoor Environment?

 For outdoor or harsh environments, choosing the right tubing depends on the considerations below for better durability.

Tubing materials should be resistant to 

• UV radiation,
• moisture,
• ozone,
• environmental conditions, such as temperature.

Where Can I Find Additional Resources for Choosing the Right Tubing?

To make the right tubing selection, consult

• manufacturers’ catalogs,
• industry publications,
• online resources for industry standards and regulations,
• tubing suppliers and experts.

We Supply High-Quality Tubing and Deliver Across the United States

We have covered all the main factors you have to consider before selecting a type of tubing for your project. However, if you do not have the experience, you should always consult with an industry expert to ensure the system’s safety, longevity, and efficiency.

Process Valves and Instruments, in Birmingham, AL, is a big supplier of any products used in pipe systems, such as tubing, valves, actuators, fittings, and other process instruments. Check out our products page to get more familiar with the products we supply and deliver across the US. Or call 800-749-8068 to discuss your project.