What are the causes and treatment methods of thermocouple tube rupture?

Thermocouples may inevitably experience sleeve rupture during use, which directly affects reliable and safe operation. Huaneng Instrument investigated the phenomenon of thermocouple tube rupture and found the cause. The main reasons for the rupture of thermocouple sleeves are as follows:
1. The thermocouple sleeve is subjected to high-speed fluid impact, resulting in excessive load and stress exceeding the limit, leading to sleeve rupture;
2. Processing defects in the thermocouple sleeve itself can lead to stress concentration and easily cause sleeve fracture;
3. Excessive pipeline vibration causes fatigue damage to the thermocouple sleeve;
When the fluid flows through the thermocouple sleeve, it induces vibration of the thermocouple sleeve, that is, resonance between the natural frequency of the thermocouple sleeve and the frequency of fluid vortex shedding. This resonance phenomenon can accelerate the damage speed of the thermocouple sleeve, leading to fracture.
Based on the above situations that can easily cause the rupture of thermocouple sleeves, we have conducted research in conjunction with the thermal control and metal specialties, and found that the occurrence of thermocouple sleeve rupture can be reduced through the following methods.