In order in order to avoid any damage to the thermowell during operation because of mechanical loads, a thermowell calculation per ASME PTC 19.3 TW-2016 is preferred for critical process conditions. In case of a calculation with negative results, the only real constructive solution so far was to shorten the thermowell stem or to increase the root and tip diameter, accepting a longer response time of the thermometer.
The new ScrutonWell � design reduces the amplitude of oscillation by more than 90 % and allows a straightforward and fast installation of the thermowell without support collar, and thus without expensive and time-consuming rework on site.
Struggle has been used successfully for many years in a wide selection 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’s put through a flow inside a pipeline. This vortex street consists of two rows of vortices with opposite directions of rotation, which detach themselves to the left and the proper of the thermowell out of phase, and this can instigate the thermowell to vibrate.
NEW ScrutonWell � design
The helical strakes, arranged round 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
More info on our thermowells are available on the WIKA website.
Learn more about the new ScrutonWell� design in the next video: