Overview
Stainless steel tubing is widely used in analytical laboratories, chromatography systems, process instrumentation, and high-pressure fluid transfer applications because of its strength, chemical resistance, and dimensional stability.
One of the most important selection criteria is pressure capability. As tubing internal diameter decreases while maintaining the same outer diameter, the pressure tolerance generally increases.
Understanding these pressure relationships can help prevent component failures and support safe operating practices.
Maximum Pressure Ratings
The following maximum pressure ratings apply to commonly used stainless steel tubing configurations.
1/8-Inch OD Tubing
| Tubing Size | Maximum Pressure |
|---|---|
| 1/8" × 2.0 mm ID | 24,000 psi |
| 1/8" × 1/16" ID | 58,800 psi |
1/4-Inch OD Tubing
| Tubing Size | Maximum Pressure |
|---|---|
| 1/4" × 4.6 mm ID | 21,000 psi |
Pressure Ratings by Internal Diameter
The following values illustrate the relationship between internal diameter and maximum pressure capability.
| Internal Diameter (mm) | Maximum Pressure (psi) |
|---|---|
| 1.00 | 28,400 |
| 0.75 | 37,500 |
| 0.50 | 56,800 |
| 0.25 | 113,600 |
| 0.18 | 150,000 |
| 0.13 | 195,000 |
As the internal diameter becomes smaller, the tubing is capable of withstanding significantly higher pressures.
Manufacturing Technology
Historically, seamless stainless steel tubing was considered the preferred choice for many analytical and industrial applications because of its excellent dimensional consistency and absence of welded seams.
Modern manufacturing processes have evolved substantially, and many manufacturers now utilize precision TIG-welded and annealed tubing technologies.
Benefits of modern production methods include:
- Improved dimensional consistency
- Enhanced concentricity
- Greater manufacturing efficiency
- Excellent pressure performance
- Reliable quality control
These manufacturing advancements support the demanding requirements of chromatography, biotechnology, medical device, automotive, and industrial markets.
Importance of Tubing Concentricity
Tubing concentricity refers to how accurately the internal diameter remains centered within the outer diameter.
High concentricity is important because it can contribute to:
- Consistent flow characteristics
- Improved pressure performance
- Reliable fitting connections
- Reduced dead volume
- Better chromatographic reproducibility
For HPLC applications, concentric tubing helps maintain system performance and minimizes variability.
Selecting the Proper Tubing
When choosing stainless steel tubing, consider:
- Maximum operating pressure
- Internal diameter requirements
- Flow rate requirements
- Solvent compatibility
- System dead volume requirements
- Fitting compatibility
The ideal tubing balances pressure capability with chromatographic performance and system requirements.
Applications
High-pressure stainless steel tubing is commonly used in:
- HPLC systems
- UHPLC systems
- LC-MS instruments
- Process analyzers
- Fluid delivery systems
- Laboratory instrumentation
- High-pressure sampling systems
Proper tubing selection helps maintain both safety and analytical performance.
Key Takeaways
- Pressure capability depends heavily on tubing internal diameter.
- Smaller IDs generally provide higher pressure tolerance.
- 1/8" × 1/16" tubing offers a maximum rating of 58,800 psi.
- 1/4" × 4.6 mm tubing offers a maximum rating of 21,000 psi.
- Modern TIG-welded and annealed tubing provides excellent dimensional precision and strength.
- Concentricity remains an important consideration for chromatography and high-pressure applications.
- For Stainless Steel High-Pressure Tubing Specifications, Available Dimensions, Pressure Ratings, Product Images, and Ordering Information, view Stainless Steel High-Pressure Tubing Specifications, Available Dimensions, Pressure Ratings, Product Images, and Ordering Information.
- For additional laboratory tubing options, view Laboratory Grade Tubing Specifications, Materials, Dimensions, and Application Information.