What Is An RTD Thermowell, Its Characteristics, Types, & Selection Criteria?

A thermowell is a device that is used to protect a temperature sensor from the environment. It is typically made of stainless steel or other corrosion-resistant material, and it has a flared end to allow for easy insertion of the sensor. The thermowell also has a small borehole that allows the sensor to be mounted flush with the bottom of the well. This ensures that the sensor is in direct contact with the medium being measured. Thermowells are often used in high-temperature or high-pressure applications, or in applications where the sensor must be replaced frequently.

Uses of Thermowell in Different Environments and Their Types!

Thermowells are used in a variety of applications, including in process and boiler vessels, to measure the temperature of liquids and gasses. They are also used in pipelines, tanks, and other vessels where it is not practical to install a sensor directly into the process. Thermowells are available in a variety of shapes and sizes, and they can be customized to meet the specific needs of the application. These are of three main types based on the design of its stem as follows:

  • Straight Thermowell: These are the simplest and most economical type. They’re best suited for applications where the process conditions are relatively benign. However, this design is not well suited for high-velocity applications or applications with a large temperature differential between the well and the process.
  • Stepped Thermowell: These are more robust than straight thermowells and can withstand greater process pressures and temperatures. They’re often used in high-pressure or high-temperature applications. It is designed to minimize the effects of high velocity and large temperature differentials.
  • Tapered Thermowell: The most common type of thermowell is the tapered type, which is designed for use with RTD temperature sensors. The taper of the well allows for the sensor to be inserted into the well and then held in place by friction. It is designed for applications with very high velocities or very large temperature differentials.


How To Select The Most Suitable Thermowell For Your Application Based On Different Selection Criteria?

There are a few key factors to consider when selecting the most suitable thermowell for your RTD temperature sensor requirement as follows:

  • Material Selection: The most common materials used for thermowells are stainless steel, brass, and bronze. Stainless steel is the most popular choice because it is the most corrosion resistant. Brass and bronze are less popular because they are not as resistant to corrosion.
  • Bore Size & Length: The length and diameter of the thermowell should be based on the application. For example, if the sensor is inserted into a pipe, then the thermowell should be the same size as the pipe. The diameter of the thermowell should also be considered. A larger diameter thermowell will be more resistant to vibration and will have a longer life.
  • Connection Type: The type of process connection is also important. The most common type of connection is a screw-type. This type of connection is easy to use and is common in small diameter thermowells. A weld-type connection is more difficult to use but is stronger and can be used in larger diameter thermowells.

Call The Experts @Heatcon Sensors To Get Support With Your Selection for The Most Suitable Type of Temperature Sensor for Your Application!

If you are unable to make a selection of the most suitable temperature sensor and thermowell combination, don’t hesitate to consult the experts at Heatcon Sensors, a leading manufacturer of all types of high-quality temperature sensing devices, who can even actually be able to customize one for you after learning your specific application needs.