What is Thermowell and Why It is Required?

28 Oct , 2021 News

Many industrial processes require harsh environments and extreme temperatures for their operation. Temperature measurement is a challenge in such circumstances.

Besides heat, there can be other conditions such as high pressure and powerful chemical substances, radioactivity etc. A regular temperature sensor may fail to stand in such an aggressive environment.

Therefore, some device is required to guarantee the mechanical protection of this equipment.

Thermowell acts as the medium of mounting these temperature sensors in industrial processes and protecting them.

What is Thermowell?

Thermowell is used to guard the temperature sensors against extreme working conditions. It is in the form of a hollow tube with one open and one closed end.

A Thermocouple, RTD or a Temperature Gauge is mounted in it through the open end. A thermowell facilitates many other functions besides safeguarding the instruments.

The sensor is easily replaced when mounted in a thermowell, and the chances of any contamination are also significantly reduced.

Thermowells are designed to maintain the integrity and accuracy of measuring instruments in high-pressure and demanding industrial processes

Ways a Thermowell Can Help:

Thermowell has evolved as an essential component of any industrial process. Owing to its benefits, both small, as well as large thermowells are manufactured.

The former is used in operations with high pressure conditions and the latter for measurements in tanks and vessels.

Power plants, Chemical industries, Petrochemicals, Refineries, Fertilizers, Oil & Gas, Cement, Steel, Glass and various other process industries require different types of Thermowells according to their applications.

Ways a thermowell can help

1. Protective Barrier

The primary purpose is to act as a protective barrier for a thermometer and other instruments. It protects the instruments from the aggressive internal environment of an industrial process which can cause damage. In addition, it forms a barrier between the instrument and the media that may exhibit turbulent conditions or is corrosive in nature.

2. Increased Serviceability

The temperature measuring instruments are mounted on the process lines using thermowell. The instrument can be very easily removed from the process, thermowell ensures no or minimal discontinuity of the process during the repair. The continuity of the process benefits in several ways. The production efficiency is not disturbed and the chances of letting the media escape are mitigated.

3. Reduced Operational Cost

The measuring instruments protected by a thermowell have increased longevity. Once installed, they can be used for a very long time. The less number of services reduce expenditure on their repair. Since one instrument has been operational for a long time, further investment is not required to purchase other instruments and maintain an inventory.

How to Choose the Right Thermowell?

Several factors influence the use of a thermowell, and one thermowell does not fit in for every application. It is made from a variety of materials depending on its usability and application. The following steps can be followed for the proper thermowell selection.

1. Select the Bore Size

The diameter of the bore decides the efficiency of the measuring instrument. Every temperature sensor, such as a thermocouple or bi-metal thermometer, requires a different bore diameter to fit in. So, the first parameter is to check if the sensing instrument fits into the thermowell.

2. Select the Material

The thermowell material should be checked to see if it can withstand the internal conditions of the process. You can verify with the material guide provided with the thermowell to make your selection. Based on the process temperature-pressure ratings, we can recommend if the thermowell will suit the industrial process.

3. Connection Type

Thermowell is available with different types of connections. Screwed or Threaded Thermowells are the most common for all types of applications. Application that requires thermowells to be replaced periodically use Flanges connections. Tapered thermowell is known to provide high strength to the thermowell and can be used in processes with a fluid having high fluid velocities as it offers increased resistance. On the other hand, the straight well-type thermowell can be used to lower fluid velocities.

Besides these three primary factors, there are many other aspects of the thermowell, such as the stem length, wall thickness, and insertion length, that should be determined before choosing a thermowell. If you are planning to purchase a thermowell, then you should contact us.

Precision Mass is one of the leading manufacturers of Screwed or Threaded, Welded, Built-Up, Flanged-Scruton thermowell and Van Stone Thermowell manufacturers in India. We perform wake frequency calculations to ensure thermowell performance in the process. Contact us today to get the best quality instruments at an affordable price.

Frequently Asked Questions About Thermowell:

Q1. What are The Types of Thermowell?
A1. The most common types of thermowells are (1) threaded, (2) socket weld, (3) weld-in, and (4) flanged.

Q2. What is the purpose of a thermowell?
A2. A thermowell acts as a barrier between a process medium and the sensing element of a temperature measuring devices.

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