In order to avoid any damage to the thermowell during operation due to mechanical loads, a thermowell calculation per ASME PTC 19.3 TW-2016 is preferred for critical process conditions. In the event of a calculation with negative results, the only constructive solution up to now was to shorten the thermowell stem or even to increase the root and tip diameter, accepting an extended response time of the thermometer.
The new ScrutonWell � design reduces the amplitude of oscillation by more than 90 % and allows an easy and fast installation of the thermowell without support collar, and therefore without expensive and time-consuming rework on site.
Detailed has been used successfully for many years in a wide variety of industrial applications to effectively suppress vortex-induced shrinkage excitation.
Functional principle
Standard thermowell
Using flow conditions, a K�rm�n vortex street can form behind the thermowell stem when it is put through a flow within a pipeline. This vortex street consists of two rows of vortices with opposite directions of rotation, which detach themselves left and the proper of the thermowell out of phase, which can instigate the thermowell to vibrate.
NEW ScrutonWell � design
The helical strakes, arranged around the thermowell stem of the ScrutonWell � design, break up the flow and therefore impede the formation of a clearly defined K�rm�n vortex street. Through the reduced amplitudes of the diffused vortices, vibrational excitation of the thermowell is avoided.
The NEW ScrutonWell � design may be used for all sort of solid machined thermowells with flange connection, in Vanstone design or for weld-in or screwed process connection.
Note
Trauma on our thermowells are available on the WIKA website.
Learn more about the brand new ScrutonWell� design in the next video: