Aluminum piping systems are widely used in various industries for transporting different gases and fluids, such as compressed air, vacuum, nitrogen, and other high-pressure applications. The type of pipe used in each system is designed to meet the specific requirements of the medium it carries, ensuring optimal performance, safety, and durability. But what about color? The color of aluminum pipes can indicate the type of gas or fluid running through them. These piping color schemes are based on convention rather than regulatory requirements — but it’s a good idea to follow them anyway. Here’s why.
Color Coding for Aluminum Pipes
The colors of aluminum piping systems are not universally required by law, but they are strongly recommended by industry standards and guidelines to ensure safety, consistency, and ease of identification. The ANSI/ASME A13.1 standard (Scheme for the Identification of Piping Systems) suggests using different colors for gases, air, water, and hazardous materials but doesn’t make color coding a legal requirement. It is often followed in industrial facilities to maintain safety and operational efficiency. Similarly, the Occupational Safety and Health Administration (OSHA) doesn’t explicitly require specific color coding for piping systems but recommends color labeling as part of a broader effort to comply with its Hazard Communication Standard.
In many industries, clients and safety inspectors expect adherence to these standards, so using color-coded pipes is often seen as essential for maintaining professional and regulatory standards. Even if not strictly required by law, using a color-coding system based on these standards is considered a best practice because it:
- Enhances safety by making it easy to identify the contents of a pipe at a glance.
- Aids in maintenance by helping workers quickly locate the correct piping during repairs or system upgrades.
- Improves compliance with health and safety guidelines, reducing the risk of accidents or violations during inspections.
Here are some typical colors used for different piping systems, although exact colors can vary depending on country-specific regulations or company standards.
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Compressed Air: Blue
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Vacuum: Grey or White
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Nitrogen: Green or Purple
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Hazardous or Flammable Gases: Yellow
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Fire Suppression Water: Red
Keep in mind that international facilities may follow different color schemes. For instance, ISO 14726 offers guidance on color-coding for piping systems in maritime environments, and some countries adopt their own local standards.
Unipipe Pipe Colors and What They Mean
Unipipe sells several different types of aluminum piping systems, color-coded for their intended applications. All of our piping systems are manufactured to high specifications and feature our leak-proof, easy-to-install aluminum pipe fittings.
UnipipeAIR (Light Blue)
UnipipeAIR is intended for compressed air distribution piping systems. UnipipeAIR is easily recognizable by its bright blue color. This is our base product, and we sell more of it than any other aluminum piping system. It is rated for compressed air applications up to 232 PSI (16 bar). This makes it appropriate for the vast majority of industrial compressed air use cases. It is available in a wide range of pipe sizes from ¾” to 10” and in 8’ or 19’ lengths.
UnipipeNITRO (Green)
Our green pipe, UnipipeNITRO, is intended for nitrogen distribution piping and other inert gases, such as argon or helium. We recommend the green pipe for carrying N2 from an in-house nitrogen generator or storage tank to end-use applications. With the increasing interest in in-house nitrogen generation, we’re seeing a lot more demand for this pipe. It is also rated for 232 PSI (16 bar) and available in 8’ or 19’ lengths, with diameters of ¾”, 1”, 1½”, 2” and 2½”.
UnipipeVAC (Grey)
UnipipeVAC comes in a medium grey and is available in all the same sizes and lengths as UniPipeAir. In fact, this is the exact same pipe, only grey instead of blue. The grey pipe is typically used for vacuum systems (e.g., vacuum packaging, vacuum molding, material handling, thin film deposition, vacuum chambers and laboratory applications, and high vacuum systems). Vacuum piping is rated differently than distribution piping; UniPipeVAC is rated to -29 inHG (-0.87 bar). -29 inHG is close to a full vacuum, making the system ideal for applications requiring low pressures. Available in diameters from ¾” to 6” and lengths of 19’ or 8’.
UnipipeHP (Dark Blue)
High-pressure compressed air and fluid applications require more substantial distribution piping. That’s where UnipipeHP (High Pressure) comes in. This pipe, in a darker blue than UnipipeAIR, is most often used for high-pressure compressed air applications and is rated for up to 1015 PSI (70 bar). High-pressure aluminum piping has much thicker pipe walls than standard compressed air pipe to withstand significant forces and ensure safe, reliable operations. In addition to compressed air, these high-pressure pipes are suitable for transport of pressurized water or other fluids. Available in 13’ and 6.6’ lengths and pipe diameters from ¾” to 2½”.
UnipipeOIL (Brown)
UnipipeOIL is made to the same specifications as our UnipipeHP and is rated for working pressures of up to 1015 PSI (70 bar). The brown pipe is intended for oils and similar fluids and is suitable for high-pressure fluid applications. Ideal for delivering pressurized oil for hydraulic and lubrication systems, machine tooling, cooling and other applications. Available in 13’ and 6.5’ lengths at diameters of ¾” or 1”.
Do the Pipe Colors Really Matter?
Since the pipe color coding system is not mandated by law, you are free to choose whichever pipes you want, as long as they are rated for your application. UnipipeAIR, UnipipeNITRO and UnipipeVAC are all the exact same pipe, finished in different colors. Likewise, UnipipeHP and UnipipeOIL are the same type of pipe with the same specifications. That means you could, if you wanted, choose the green pipe for compressed air to match your plant color scheme, for example. There may also be situations when you need to choose based on the available pipe diameters; UnipipeAIR and UnipipeHP are available in a wider range of pipe sizes than UnipipeNITRO, UnipipeVac and UnipipeOIL.
However, whenever possible, we do recommend using the colors as they are intended and labeled. Color coding distribution piping systems using industry-standard colors can greatly enhance safety and simplify maintenance. You don’t want an installer or maintenance technician to make a mistake because they expected air out of the dark blue pipe and got oil instead.
If you are using non-standard colors in your plant, make sure they are clearly labeled and everyone understands what pipes are carrying before performing any work or hooking up new equipment. The ANSI/ASME A13.1 standard has detailed recommendations for label colors, placement, wording and markings. Even when using standardized pipe colors, labeling is important to indicate the flow direction and provide more detail on contents and pressure levels.
Find the Best Aluminum Piping System at Unipipe
Unipipe carries a full range of aluminum piping options for compressed air, nitrogen and inert gases, oil, high vacuum, and high-pressure air and fluid applications. Our top-of-the-line aluminum piping systems are:
- Fast and easy to install, with no special tools required.
- Durable and corrosion resistant for longevity and performance.
- Highly leak resistant with secure, proprietary fittings.
Not sure which Unipipe product is best for your application? Contact us for support!
