Temperature · Measurement
Thermowell
A closed end metal tube welded or threaded into the pipe, into which the temperature sensor is inserted.
What it does
Holds the pressure and protects the sensor from flow and corrosion, so the sensor can be changed without opening the line.
Basics
| Design check | Wake frequency and stress per ASME PTC 19.3 TW |
| Shapes | Straight, tapered or stepped |
| Mount | Threaded, flanged or welded |
Common failures
- Too long for the flow velocity, it vibrates and breaks
- Air gap that slows the temperature response
Troubleshooting
- Symptom
- Temperature responds slowly
- Likely cause
- Sensor not touching the bottom of the well
- What to check
- Use a spring loaded sensor of the right length