A Complete Guide to Pneumatic Tube: Types, Functions, and Applications

I. Composition of Pneumatic Systems

II. What is a Pneumatic Tube?

A pneumatic tube is a critical connecting component in pneumatic systems. It is an automated logistics system that rapidly transports small items through sealed tubing using pressure differentials (compressed air or vacuum suction). In pneumatic systems, pneumatic tubes connect air sources, control components, and actuators, ensuring stable and efficient operation.

III. Working Principle of Pneumatic Tubes

Pneumatic tubes connect compressed air sources with various pneumatic components (such as solenoid valves and cylinders) and efficiently transmit air medium within a closed loop. The airflow in the system must maintain stable speed and pressure while minimizing energy loss, thus ensuring the stability and responsiveness of the entire pneumatic system.

IV. Classification of Pneumatic Tubes

A. Classification by Material

1. Polyurethane (PU) Tube
Features:

• Divided into Polyester-based PU tube (Air: -20℃ ~ +70℃) and Polyether-based PU tube (Air and water: -40℃~ +70℃). Working pressure: 10bar.
• Excellent Mechanical Properties: Flexible yet resistant to deformation, with high mechanical strength, excellent abrasion and compression resistance, ensuring superior durability.
• Cost-Effective Performance: Lightweight and aging-resistant, significantly reducing replacement frequency and maintenance costs.
• Excellent Low-Temperature Flexibility (Polyether-based polyurethane): Withstands temperatures as low as -40°C, maintaining exceptional flexibility in extreme cold without becoming brittle.
• Superior Hydrolysis Resistance (Polyether-based polyurethane): Ideal for humid or moisture-prone environments, resistant to aging over long-term use, long service life.

Applications: Widely used in pneumatic systems, automation equipment, rapid circulation systems, etc.

2. Nylon (PA) Tube
Features:

• Outstanding Mechanical Properties

Excellent tensile and impact resistance, with mechanical strength far exceeding ordinary plastic tubes, capable of withstanding high working pressures. Superior wear resistance makes it suitable for high-friction environments (e.g., pneumatic conveying, hydraulic systems).

• Excellent Weather Resistance

– Oil and Solvent Resistance: Resistant to mineral oils, lubricants, fuels, etc., making it ideal for automotive fuel lines and industrial lubrication systems.

– Chemical Corrosion Resistance: Can withstand weak acids, alkalis, and various organic solvents.

– Wide temperature range: -40℃ to +120℃, suitable for high-temperature, high-pressure, or low-temperature environments.

• Lightweight Design

– Lightweight (density only 1/7 of metal pipes): Easy to transport and install.

– Flexible and easy to bend: Minimum bending radius can reach 4 times the pipe diameter, suitable for complex routing needs and reducing joint usage.

– Excellent Fatigue Resistance: Resists aging and cracking under frequent bending or vibration, extending service life.

• Efficient Fluid Transfer

– Low-Flow-Resistance Design: Smooth inner wall with a small friction coefficient reduces pressure loss and improves fluid transfer efficiency.

– Anti-Static and Flame-Retardant Options: Some models can be equipped with anti-static or flame-retardant additives, making them suitable for flammable and explosive environments (e.g., fuel delivery, electronic equipment).

Applications: Widely used in pneumatic and hydraulic systems, automotive components, including fuel systems, cooling systems, air intake systems, cable protection, braking systems, and the connection/fastening of interior automotive parts.

3. Polyethylene (PE) Tube
Features:

• Excellent Chemical Resistance: Resistant to acids, alkalis and other chemicals. Working temperature: -20℃~ +60℃.
• Good Flexibility: PE tubes are lightweight and flexible (though less flexible than TPU tubes), allowing easy bending during installation.
• Non-toxic & Hygienic: Polyethylene is a food-grade safe material, silicone-free, suitable for potable water delivery without contaminating water quality.

Applications: Suitable for use in RO drinking systems, purifiers, water treatment systems, commercial water systems, misting systems, etc.

4. Teflon (PTFE) Tube
Features:

• Excellent chemical resistance: almost inert to all chemicals, withstands strong acids (e.g., aqua regia), strong alkalis, organic solvents, etc. Ideal for corrosive media transport in chemical, laboratory, and pharmaceutical industries.
• Extreme temperature performance: ultra-wide range from -65℃ to +260℃, maintains strength and flexibility even in extreme heat or cold.
• Outstanding physical properties: ultra-low friction coefficient (~0.04), minimal fluid resistance. Permanently non-stick surface prevents particle or dust adhesion.
• Excellent aging resistance: great UV and weather resistance, long-term outdoor use without degradation.
• Excellent electrical insulation: very low dielectric constant (~2.0), low dielectric loss, high voltage resistance, and high volume resistivity (≥10¹⁸Ω·cm), stable insulation even under high-frequency, high-voltage environments.

Applications: Chemical and industrial fluid transport, electronics and electrical, food machinery, medical and pharmaceutical, laboratories, etc.

B. Classification by Structure

1. Straight Tube (Single Layer)
The inner wall of the above-mentioned tubes is smooth and unobstructed, resulting in low fluid resistance, high flow efficiency, and lower cost.

2. Spiral/Coiled Tube
Excellent coil memory, freely extendable/compressible with strong rebound ability. Saves space and easy to install and maintain. Common types: PU spiral tube, PA12 nylon spiral tube, PFA/FEP spiral tube.

3. Multi-layer Composite Tube

• Reinforced Tube: middle layer reinforced with fiber yarn, normal working pressure is 2–3 times that of standard single-layer tubes. Common types: PU reinforced tube, PA12 reinforced tube, PVC reinforced tube.
• Paint Tube: outer layer made of polyurethane, inner layer PA12. Good corrosion and insulation properties, used for paint and coating transport.
• Fluoropolymer Double-layer Tube: outer layer made of polyurethane or nylon, inner layer of PFA fluoropolymer. High temperature, corrosion, and solvent resistance; more flexible than single-layer fluoropolymer tubes.
• TPEE Firefighting Tube: both outer and inner layers made of TPEE, suitable for conveying perfluorohexanone, heptafluoropropane. Mainly used in energy storage cabinets, automotive fire extinguishing systems, etc.

C. Classification by Functional Characteristics

1. Anti-static Tube

PU anti-static tube, nylon anti-static tube, PFA anti-static tube, etc. Surface resistance typically 10⁶~10⁹Ω, suitable for electronics, semiconductors, dust-sensitive environments.

2.Flame-retardant Tube

Common types include PU double-layer flame-resistant tube, PU triple-layer flame-resistant tube (with aluminum film middle layer), nylon double-layer flame-resistant tube. Suitable for environments with welding sparks. Flame retardancy rating: UL94 V-0.

3. Food-grade Tube

Food-grade PU tube, PE tube, PVC tube, silicone tube, etc.

Summary

As a vital connecting component in pneumatic systems, pneumatic tubes come in various types and functions. Users should select suitable materials and structures based on operating environments, pressure requirements, fluid media, and spatial layout. Proper selection can enhance equipment efficiency, reduce maintenance costs, and extend the system’s service life.

If you require specific product selection guidance or technical documentation, feel free to contact our technical support team.