Date: 16-JUNE-2023 Last Updated: 4-SEPTEMBER-2026
Introduction
Polytetrafluoroethylene (PTFE) tubing is widely used in chromatography, sample preparation, laboratory fluid handling, chemical transfer, and general analytical applications. PTFE is valued for its exceptional chemical resistance and broad temperature operating range, making it suitable for transporting a wide variety of solvents, reagents, and aqueous solutions.
While PTFE tubing performs well in many laboratory environments, pressure capability is highly dependent on tubing dimensions and operating conditions. Understanding these limitations helps ensure safe and reliable performance.
Why PTFE Tubing Is Popular in Laboratories
PTFE tubing offers several characteristics that make it attractive for analytical and laboratory applications.
Key Benefits
- Excellent chemical resistance
- Broad solvent compatibility
- Low coefficient of friction
- Non-reactive surface properties
- Wide operating temperature range
- Flexibility and ease of installation
- Low extractables profile
These properties have made PTFE a common choice for fluid transfer lines, solvent delivery systems, reagent transport, and low-pressure chromatography applications.
Temperature Stability of PTFE
PTFE is known for its outstanding thermal stability compared to many other tubing materials. Typical temperature capability extends to approximately: 500°F (260°C)
PTFE also maintains useful mechanical properties at extremely low temperatures and retains a degree of flexibility even under very cold operating conditions. However, temperature capability alone should not be used to determine tubing suitability.
How Temperature Affects Pressure Capability
Although PTFE is highly temperature resistant, increasing temperature generally reduces the tubing's ability to withstand pressure.
As temperature rises:
- Mechanical strength decreases
- Deformation resistance decreases
- Burst resistance decreases
- Long-term dimensional stability may be reduced
For this reason, pressure ratings obtained at room temperature should not automatically be assumed for elevated-temperature applications.
When both pressure and temperature increase simultaneously, the allowable operating range of PTFE tubing may be substantially reduced.
The Importance of Wall Thickness
Wall thickness is one of the primary factors affecting PTFE tubing pressure capability.
In general:
- Thicker walls support higher pressures
- Thinner walls support lower pressures
- Larger internal diameters reduce pressure capability
- Smaller internal diameters generally increase pressure capability
When selecting tubing, both internal diameter and wall thickness should be considered together rather than independently.
PTFE Tubing Pressure Reference Chart
Approximate upper use pressure limits for PTFE tubing at 20°C. Values are intended as general guidance and actual operating limits may vary depending on application conditions, tubing dimensions, safety factors, and temperature.| Wall Thickness (mm) / Inner Diameter (mm) | Pressure Limit: bar / psi |
|---|---|
| 2.0 / 20 | 5.8 / 84.1 |
| 1.5 / 20 | 4.1 / 59.5 |
| 1.0 / 20 | 2.9 / 42.1 |
| 0.75 / 20 | 2.1 / 30.5 |
| 0.50 / 20 | 1.9 / 27.6 |
| 0.20 / 9.7 | 1.65 / 23.9 |
Understanding the Pressure Data
The pressure values shown in the chart are intended as reference guidelines and are based on tubing dimensions measured at approximately 20°C.
These values illustrate several important design principles:
- Pressure capability decreases as wall thickness decreases.
- Pressure capability is influenced by internal diameter.
- Operating temperature can significantly affect pressure performance.
- Tubing should always be selected with an appropriate safety margin.
For critical applications, operating conditions should be evaluated carefully before selecting tubing dimensions.
Common Applications for PTFE Tubing
PTFE tubing is frequently used for:
- Solvent transfer
- Mobile phase delivery
- Buffer transfer
- Sample collection
- Reagent transport
- Laboratory fluid handling
- Chemical processing
- Instrument fluid paths
- Low-pressure chromatography systems
Because of its broad chemical resistance, PTFE is often selected when aggressive solvents or mixed solvent systems are involved.
Selecting the Proper PTFE Tubing
When choosing PTFE tubing, laboratories should consider:
- Chemical compatibility
- Operating pressure
- Operating temperature
- Internal diameter requirements
- Flow rate requirements
- Wall thickness
- System safety factors
Selecting tubing based solely on chemical compatibility may result in insufficient pressure capability for the intended application.
Conclusion
PTFE tubing is a highly versatile laboratory material that combines exceptional chemical resistance, low friction, and broad temperature stability. However, tubing performance depends on more than chemical compatibility alone. Pressure capability is strongly influenced by wall thickness, internal diameter, and operating temperature. Understanding these relationships helps laboratories select PTFE tubing that provides reliable performance and safe operation in chromatography and laboratory fluid-handling applications.
