In pneumatic systems, tubing selection should not be based solely on material names. It should begin with a clear understanding of the application, routing method, and whether regulatory or industry standards apply.

Selection criteria vary depending on the application conditions. For example, automation systems require consideration of whether tubing moves with equipment; fixed routing requires stable positioning; tool-use air lines require consideration of dragging and operating conditions; and commercial vehicle air brake systems require compliance with relevant regulations and standards.

Therefore, pneumatic tubing selection should begin with identifying the intended use, followed by verification against operating conditions and product specifications.

Pneumatic Tubing Selection Process

Tubing selection should follow a step-by-step evaluation based on actual usage conditions, rather than starting from material names.

• Confirmation of regulatory and standard requirements
• Identification of application
• Determination of routing method
• Evaluation of operating conditions
• Verification of suitability based on product specifications

Selection Based on Routing Method

Routing method is a primary factor in pneumatic tubing selection. Different routing configurations lead to different tubing types.

Dynamic Routing

When tubing is required to move with equipment, undergo repeated bending, or continuously change position, it is classified as dynamic routing.
Typical applications include automation equipment, robotic arms, and sliding systems.

Common selection: PU tubing

Fixed or Semi-Fixed Routing

When tubing remains largely stationary after installation, or only undergoes minimal movement, it is classified as fixed or semi-fixed routing.
Typical applications include main air distribution lines, long-distance transmission, or internal equipment piping.

Common selection: Nylon tubing、 LDPE tubing

Tool and On-Site Air Supply Lines

When tubing is used for air tools, maintenance operations, or on-site air supply, and requires dragging or repositioning, it is considered a tool-use air supply application.
This type of application is neither fixed piping within equipment nor dynamic routing with repeated bending, and requires consideration of ease of handling and operating conditions.

Common selection: Coiled tubing、 Braided air hose（including Hybrid air hose）

Evaluation Based on Operating Conditions

Operating conditions are not the sole starting point for selection, but are used to verify whether the selected tubing type meets actual application requirements.
Key factors include working pressure, temperature, external environment, and proximity to heat or sparks.

Working Pressure Conditions

When applications involve clearly defined higher working pressure, pressure conditions may be used as an initial screening factor to narrow down suitable tubing options.
In practice, tubing type should still be determined based on application purpose and routing method, followed by verification of working pressure ratings for the selected dimensions. Pressure resistance varies depending on tubing diameter, wall thickness, and structural design. Therefore, pressure alone should not be used to determine tubing type.

Temperature Conditions

When tubing is used in low-temperature, high-temperature, or fluctuating temperature environments, actual operating temperature must be considered.
Temperature variations may affect flexibility and bending performance.

Environmental Conditions

When tubing may come into contact with oil mist, liquids, or other media, material compatibility must be evaluated.
Different materials may perform differently depending on the media. Selection should be based on actual exposure conditions.

Spark or Heat Exposure Conditions

When tubing is installed near welding or metal processing equipment, where exposure to sparks or high temperatures is possible, heat and spark impact must be considered.
In such conditions, tubing should be evaluated for flame-retardant characteristics to reduce risk from heat or spark exposure.

Common selection: Anti-Spark Tubing (Flame-retardant tubing)

Typical Tubing Selection by Application Scenario

The following examples illustrate typical tubing configurations under different application conditions.

Automation Equipment

Pneumatic systems in automation equipment often include both dynamic and fixed routing:
Dynamic sections: PU tubing
Fixed sections: Nylon tubing

Commercial Vehicle Air Brake Systems

Tubing used in air brake systems must comply with relevant regulations and standards:
Vehicle internal lines: Air brake tubing
Tractor–trailer connection: Coiled air brake hose

Tool and On-Site Air Supply

Applications involving tools and on-site air supply typically require mobility:
Air supply for tools: Braided air hose / Hybrid Air Hose
Retractable use: Coiled tubing

Key Principles of Pneumatic Tubing Selection

Pneumatic tubing selection should be based on actual application conditions rather than material names or a single factor. In general, the process should begin with confirming regulatory requirements, followed by identifying application purpose and routing method, and finally verifying suitability through operating conditions and product specifications. Material is only one part of the selection process. The key factor is how the tubing is used and whether it matches actual application conditions.

Further Reading

→ Pneumatic Tubing Classification and Selection Mapping (Routing Method × Operating Conditions)

→ PU Tubing vs. Nylon Tubing: Selection and Application Differences

→ Differences Between Air Brake Nylon Tubing and Nylon Tubing

→ UL94 V-0 Flammability Classification