Tech Team · Kintek Solution

Quartz test tubes are widely used in high-temperature applications due to their thermal stability and transparency. The maximum temperature a quartz test tube can withstand depends on the specific conditions of use, such as duration, atmosphere, and pressure. Under normal atmospheric conditions, quartz tubes can tolerate temperatures up to 1100°C for long-term use and 1200°C for short-term use. However, exceeding 1200°C can lead to deformation. In vacuum conditions, the maximum temperature is reduced to 1000°C. Additionally, quartz tubes have a softening point of 1270°C, but prolonged exposure to high temperatures (e.g., 1200°C) should be limited to avoid damage. For higher temperature requirements, alternative materials like corundum tubes are recommended.

Key Points Explained:

1. Temperature Limits Under Atmospheric Conditions:

   • Quartz tubes can withstand up to 1100°C for long-term use and 1200°C for short-term use under normal atmospheric pressure.
   • Exceeding 1200°C can cause the quartz tube to deform, making it unsuitable for higher-temperature applications.

2. Temperature Limits Under Vacuum Conditions:

   • In vacuum environments, the maximum temperature quartz tubes can handle is reduced to 1000°C.
   • This reduction is due to the differences in thermal conductivity and stress distribution under vacuum compared to atmospheric conditions.

3. Softening Point and Prolonged Exposure:

   • Quartz tubes have a softening point of 1270°C, but this does not mean they can operate safely at this temperature.
   • Prolonged exposure to temperatures close to 1200°C (e.g., for more than 3 hours) can lead to damage or failure of the tube.

4. Heat-Cool Cycles:

   • Quartz tubes are less resistant to heat-cool cycles compared to materials like alumina or superalloy tubes.
   • Frequent thermal cycling can lead to cracking or fatigue, reducing the lifespan of the quartz tube.

5. Alternative Materials for Higher Temperatures:

   • For applications requiring temperatures above 1200°C, materials like corundum tubes are recommended.
   • Corundum tubes offer better thermal stability and durability at extreme temperatures compared to quartz.

6. Practical Considerations for Purchasers:

   • When selecting quartz tubes, consider the maximum operating temperature, duration of use, and environmental conditions (e.g., atmospheric or vacuum).
   • Ensure the quartz tube is used within its specified limits to avoid deformation or damage.
   • For applications involving frequent thermal cycling or higher temperatures, explore alternative materials like alumina or corundum.

By understanding these key points, equipment and consumable purchasers can make informed decisions about the suitability of quartz tubes for their specific applications and ensure optimal performance and longevity.

Summary Table:

Condition	Temperature Limit	Key Considerations
Atmospheric Conditions	Up to 1100°C (long-term), 1200°C (short-term)	Exceeding 1200°C can cause deformation.
Vacuum Conditions	Up to 1000°C	Reduced due to thermal conductivity and stress distribution differences.
Softening Point	1270°C	Prolonged exposure near 1200°C can damage the tube.
Heat-Cool Cycles	Less resistant	Frequent cycling can lead to cracking or fatigue.
Alternative Materials	Corundum tubes	Recommended for temperatures above 1200°C or frequent thermal cycling applications.

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