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 recommended for critical process conditions. In the event of a calculation with negative results, the only real constructive solution so far was to shorten the thermowell stem or even to raise the root and tip diameter, accepting an extended response time of the thermometer.
Sex ScrutonWell � design reduces the amplitude of oscillation by more than 90 % and allows an easy and fast installing the thermowell without support collar, and therefore without expensive and time-consuming rework on site.
This helical design 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
In certain flow conditions, a K�rm�n vortex street can form behind the thermowell stem when it’s subjected to a flow inside a pipeline. This vortex street includes two rows of vortices with opposite directions of rotation, which detach themselves 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 around the thermowell stem of the ScrutonWell � design, split up the flow and thus 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 can be used for all kind of solid machined thermowells with flange connection, in Vanstone design or for weld-in or screwed process connection.
Note
Further information on our thermowells are available on the WIKA website.
Learn more about the brand new ScrutonWell� design in the following video: