Thermowells can be seen as the protectors of temperature measurement. The thermowell provides the necessary protection to make sure the temperature measuring equipment can keep operating for as long as possible. Especially the temperature sensing parts inside the thermometer or sensor need to stay intact. The reason is that these parts are very sensitive and vulnerable. Temperature related equipment in industrial processes are often exposed to harmful external influences, meaning protection is vital.
What are you protecting the temperature sensor from?
Temperature sensors are often used in situations in which they are exposed to forces that can do damage. Especially the sensing elements in temperature sensors are fragile. These sensing elements are essential for the entire instrument. If this sensing element doesn’t work, your instrument is useless.
Reasons for damage to these temperature sensors can be;
- Excessive pressure from high flow rates.
- A very viscous medium putting strain on the insert.
- Vibrations in the system.
Why use a thermowell?
There are different reasons for using a thermowell. The general reason is protecting temperature sensors from the harmful conditions named above. But there are more reasons for using thermowells. The combination of these reasons results in choosing the usage of a thermowell, in most industrial processes which require measuring temperatures.
These are some more reasons for using thermowells;
- Protection of the sensors from harmful conditions.
- Increase sensor lifespan. When a temperature sensor is protected from external influences, it’s most likely to last longer. This, of course, is good for costs.
- Allow sensors to be replaced without draining the system. So no delays due to replacement or maintenance of thermometers.
- Safety. It might seem logical, but it’s much safer using a thermowell in an industrial process. Direct contact with media is blocked because of the thermowell.
Differences in thermowells
Thermowells differ from each other by:
- Connection: The way thermowells are connected to the process. Threaded connections are the most common.
- Length: The insertion length of the thermowell. Some situations require a bigger insertion depth into the medium than other situations. Thermometers are chosen considering this insertion depth. Of course, a thermowell needs to match this length.
- Shape of the thermowell: Different designs provide better protection against pressure, corrosion or viscosity.
- Extension length: Sometimes, the application is equipped with isolation covers. In this case, an extension length is required to be able to reach through the isolating cover.
- Material: Different circumstances require different thermowell materials. The most used material is stainless steel.
Making your thermowell choice
As you can see, there are so many things to take into account when making your thermowell choice. Please don’t hesitate to ask our TUVO Instruments experts for help!