What's the Best Piping Material for Compressed Air? (And Why PEX & PVC Aren't Safe)

• Pros: Galvanized steel pipes are durable and can withstand high pressures. They are relatively inexpensive and readily available. They can also resist corrosion to some extent.
• Cons: Over time, galvanized pipes can corrode from the inside, leading to reduced airflow and potentially contaminating the compressed air with rust particles. Installation can be labor-intensive, and they may require regular maintenance to prevent corrosion buildup.

The zinc coating in galvanized systems provides temporary protection but often deteriorates over time, especially at threaded connections where the coating is compromised during installation. Once corrosion begins, it can progress rapidly, leading to reduced system performance and potential contamination issues.

Plastic & Polyethylene (PE) Piping Options and Limitations

Plastic & polyethylene (PE) pipes are lightweight, corrosion-resistant, and relatively inexpensive compared to metal pipes. However, they do not offer the safety or longevity of metal piping.

• Pros: PE is lightweight and very corrosion-resistant. Ideal for below ground direct burial applications.
• Cons: PE may not be suitable for high-pressure or high temperature applications. They are also susceptible to degradation from UV light exposure. Plastic pipes are not as durable as metal pipes, resulting in a shorter service life in a compressed air system. Typically PE systems are fused together, requiring special equipment for installation.

IMPORTANT SAFETY NOTE: PVC piping is NOT rated for use with compressed air and will shatter at high pressures, creating a risk of property damage, serious injury, or death.

The dangers associated with PVC mirror those of PEX — both materials can fail catastrophically under compressed air pressure. While there are some specialized engineered plastics rated for compressed air applications, these tend to be considerably more expensive than standard PVC or PEX and still typically offer lower pressure ratings than metal alternatives.

Even for specialty PE Pipes that are properly rated for compressed air, always verify the manufacturer's specific pressure ratings and installation requirements before proceeding.

Copper Piping for Compressed Air

Can copper pipe be used for compressed air? Copper piping is sometimes used for compressed air distribution, though it is another costly alternative. Lighter than black iron, copper also requires installation by a skilled plumber or pipefitter.

• Pros: Copper pipes are lightweight, corrosion-resistant, and can handle high pressures.
• Cons: Copper pipes are more expensive than iron, galvanized steel, or aluminum, which can increase installation costs. Skilled labor for installation and changes can also be costly. Copper pipes may be susceptible to damage from acidic or alkaline substances. Fittings are typically soldered, brazed, or pressed onto the pipes making them not reusable.

Copper offers excellent corrosion resistance and smooth interior surfaces that minimize pressure drop, making it a good technical choice for compressed air systems. However, its high material cost and the requirement for skilled soldering or brazing during installation often make it economically impractical for larger systems.

Stainless Steel: When Is It Worth the Investment?

Stainless steel piping is a durable but costly alternative for a compressed air piping system. Stainless steel is sometimes recommended for food or pharmaceutical applications where compressed air is in direct contact with the product. It requires fitting by a skilled plumber or welder.

• Pros: Stainless steel compressed air pipes offer excellent corrosion resistance and are suitable for applications where cleanliness and purity of the compressed air are critical. They have a long lifespan and require minimal maintenance.
• Cons: Stainless steel pipes are the most expensive option among the materials listed here. They are also heavier than most other materials, which can make installation more challenging and costly.

For specialized applications where compressed air directly contacts food products or pharmaceuticals, stainless steel may be the preferred choice despite its cost. It offers superior cleanliness and can withstand aggressive cleaning protocols required in these industries.

Aluminum Piping: The Modern Solution for Compressed Air

Aluminum piping, such as Unipipe, is rapidly becoming one of the most popular options for compressed air systems. Aluminum piping offers an outstanding balance of light weight, corrosion resistance and ease of installation, making it an excellent choice for a compressed air piping system.

• Pros: Aluminum is lightweight and flexible, facilitating easy installation and modification. It is also highly corrosion-resistant, ensuring clean air delivery and system longevity. Unipipe aluminum compressed air piping systems are designed with specialized quick-clamp fittings, so they do not require skilled labor or welding to install. While aluminum has higher initial costs than black iron, galvanized steel, or plastic, savings on installation, maintenance, and energy efficiency can offset this.
• Cons: Although not everyone has heard of it yet, ‘blue pipe systems’ such as UNIPIPE have been around for years! Although it is getting better every day, pipes and fittings are not as readily available as traditional materials like iron or copper, that is often available at your local hardware store if needed.

The shift toward aluminum piping in industrial compressed air systems reflects a growing recognition of its superior performance characteristics and long-term economic benefits. Unlike traditional materials, aluminum provides a clean, efficient air delivery system that maintains its performance characteristics throughout its lifespan.

Modern aluminum systems also feature smooth interior surfaces that minimize friction and pressure drop, leading to greater energy efficiency compared to rough-surfaced alternatives like black iron. This efficiency advantage grows over time as traditional materials corrode and develop even rougher interior surfaces.

Aluminum vs. Other Materials: A Comprehensive Comparison

When evaluating piping materials for compressed air, it's important to consider all factors that affect performance and total cost of ownership:

Pressure Handling Capability

• Aluminum systems like UnipipeAIR are rated for standard industrial pressures up to 232 PSI.
• Black iron and galvanized steel typically offer similar pressure ratings.
  Copper and stainless steel can handle high pressures, but at significantly higher cost.
• PEX and PVC are unsafe for compressed air, regardless of their water pressure ratings.
  

Corrosion Resistance

• Aluminum naturally forms a protective oxide layer that prevents ongoing corrosion.
• Stainless steel offers excellent corrosion resistance at a premium cost.
• Copper resists corrosion well, but can be affected by certain contaminants.
• Galvanized steel provides temporary protection that degrades over time.
• Black iron corrodes readily, particularly in moist environments.
  

Installation Complexity

• Aluminum systems with push-to-connect fittings can be installed without specialized skills.
• All metal alternatives require threading, welding, or soldering skills.
• Installation time for aluminum is typically 50-70% less than traditional materials.
  

System Weight

• Aluminum is approximately 1/3 the weight of steel, reducing structural support requirements.
• Lighter weight also simplifies handling and installation, particularly in elevated locations.
• Reduced weight can be particularly important in facilities with limited structural capacity.
  

Long-Term Maintenance

• Corrosion-resistant materials (aluminum, stainless steel) require minimal maintenance.
• Black iron and galvanized systems often need component replacement due to corrosion.
• Leak rates are typically much lower with aluminum systems than with threaded connections.
  

UnipipeAIR: Leading the Aluminum Revolution

With a wide range of pipe sizes (3/4" to 10") and the highest-rated working pressures (up to 1015 PSI with UnipipeHP), Unipipe can meet even the most demanding project specifications.

The UnipipeAIR system represents the cutting edge in aluminum compressed air piping, with features specifically designed to maximize performance while minimizing installation costs:

• Quick-connect fittings that create secure, leak-free connections without special tools.
• Full range of components for comprehensive system design.
• Color-coded blue piping for easy system identification.
• Lightweight construction that reduces installation effort and structural requirements.
• Compatibility with existing systems through appropriate transition fittings.
• Smooth interior surface that maintains optimal flow characteristics throughout system life.
  

Aluminum piping systems from Unipipe are:

• Fast and easy to install or modify without specialized tools or skilled labor.
• Lightweight and easy to handle.
• Resistant to leaks and corrosion.
• Flexible and adaptable for any compressed air application.
• Durable and low maintenance for extended service life.
  

Best Practices for Compressed Air Piping Installation

System Design Fundamentals

Proper system design is essential for compressed air efficiency, regardless of piping material:

• Size main distribution lines generously to minimize pressure drop.
• Consider loop systems rather than linear runs for more consistent pressure.
• Install drain legs at low points to collect and remove condensate.
• Position takeoff points at the top of main lines to minimize moisture transfer.
• Include isolation valves to facilitate maintenance and system modifications.
• Consider future expansion needs when sizing main distribution lines.
  

Aluminum piping systems simplify many of these design considerations through their modularity and ease of modification, allowing systems to evolve with changing requirements.

Installation Tips for Optimal Performance

When installing any compressed air piping system, these practices will help ensure optimal performance:

• Support piping at appropriate intervals according to manufacturer's specifications.
• Allow for thermal expansion, particularly in systems with significant temperature variations.
• Ensure proper sealing of all connections — aluminum systems with O-ring seals typically provide superior results compared to threaded connections with sealant.
• Test the system for leaks before full operation.
• Document the system layout for future reference and modifications.
  

Aluminum systems with push-to-connect fittings dramatically simplify these installation processes compared to traditional materials, reducing both labor requirements and the potential for installation errors.

Special Applications and Considerations

High-Pressure Systems: When Standard Isn't Enough

For applications requiring pressures beyond standard industrial ranges, specialized systems like UnipipeHP provide solutions rated for pressures up to 1015 PSI. These high-pressure aluminum piping systems maintain the installation advantages of standard aluminum systems while providing the pressure capacity required for demanding applications.

Outdoor and Extreme Environment Installations

Compressed air systems installed outdoors or in extreme environments require special consideration:

• Both aluminum and stainless steel offer excellent resistance to environmental corrosion.
• Protection from direct UV exposure may be necessary for some installations.
• Freeze protection strategies should be implemented in cold climates.
• Additional condensate management may be required in high-humidity environments.
  

Aluminum's natural corrosion resistance makes it particularly well-suited for challenging environmental conditions, maintaining its performance characteristics without additional protective measures in most situations.

Converting Your System to Aluminum: The Process

Upgrading an Existing Iron or Steel System

Many facilities are transitioning from older iron or steel piping to modern aluminum systems.

New Installation Best Practices

For new compressed air installations, aluminum piping offers significant advantages:

• Simplified installation reduces labor costs and project timelines.
• No special tools or skills required for assembly.
• Reduced weight simplifies handling and mounting.
• System can be easily modified if requirements change.
• Excellent long-term performance minimizes maintenance requirements.
  

Working with suppliers who provide design support ensures optimal system configuration for your specific application requirements.

Conclusion: Making the Smart Choice for Your Compressed Air System

The performance advantages of aluminum, combined with its installation simplicity and long-term reliability, make it the clear winner for compressed air applications across virtually all industries. The higher initial material cost is consistently offset by reduced installation labor, improved system performance, and minimal maintenance requirements over the system's lifetime.

Most importantly, choosing aluminum eliminates the dangerous temptation to use inappropriate materials like PEX or PVC that present serious safety risks in compressed air applications. The peace of mind that comes with a properly designed and installed system using appropriate materials is invaluable.

Upgrade to a modern, durable aluminum piping system today!