In our previous two blog posts relating to temperature measurement, we looked at an Introduction to Temperature Measurement and The Value of a Temperature Transmitter. This third blog post in this series on temperature measurement will focus on Thermowells. Thermowells are a mainstay in the process industry, but in order to be efficient and reliable, they require very careful calculations and specific designs.
Temperature sensors are rarely inserted directly into an industrial process. Instead, they are installed into a thermowell to isolate them from the potentially damaging process conditions of flow-induced stresses, high pressure, or corrosive chemical effects. The thermowell is installed in the pipe, and the temperature-sensing rod that covers the sensor is suspended in the process flow.
Emerson has four different thermowell stem profile options available: straight, stepped, tapered, and twisted. All have their reasons for use depending on the application, but let’s focus on the twisted design of the Rosemount™ Twisted Square™ Thermowell.
A New Twist on Thermowell Design
The Rosemount Twisted Square Thermowell’s unique twisted design is uniform for the entire length of the stem. This Rosemount patented design is exceptionally good at suppressing the harmful vortex-induced vibrations that a thermowell experiences in process applications. Compared to other thermowell designs, the Twisted Square will provide the most accurate and repeatable temperature measurements. The twisted design also allows for proper stem immersion in the pipe – close to 50% immersion is ideal – to ensure better accuracy. Learn more about the Rosemount Twisted Square Thermowell here.
Eliminate the Biggest Thermowell Design Pain
We all know thermowell calculations are tedious and time-consuming to do manually, so we created a solution.
The Rosemount Thermowell Design Accelerator is a free online tool that accurately and quickly executes thermowell calculations. It’s easy to use and intuitively guides you through complex projects by helping you complete what used to take up to 50 hours in 15 minutes, saving you time and money.
The Accelerator can automatically iterate up to 1,000 thermowell tags, ensuring all are optimized for their process conditions and meet the latest ASME PTC 19.3 TW standards.
If thermowell tags do not to pass calculations and changes are necessary, the Accelerator will continue to iterate until it reaches a solution by automatically making changes to the dimensional parts of the thermowell. This helps you to avoid guess work and makes sure you always stay in compliance with the standards.
Once calculations are complete, you will receive valid Rosemount sensor and thermowell product models so you can avoid building model codes from catalogs or product data sheets and obtain error-free designs. The Accelerator also provides industry-standard required reports for full traceability and history of calculations performed to meet application requirements. Learn more about and try out the Rosemount Thermowell Design Accelerator here.
For a complete technical resource on all things process temperature, download The Engineer’s Guide to Industrial Temperature Measurement, 2022 Edition, and keep an eye out for our final blog post in this temperature measurement series that will focus on Rosemount X-well™ Technology and its updated design.
