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 recommended for critical process conditions. In the event of a calculation with negative results, the only real constructive solution up to now was to shorten the thermowell stem or even to increase the root and tip diameter, accepting a longer response time of the thermometer.
The new ScrutonWell ï¿½ design reduces the amplitude of oscillation by more than 90 % and allows a straightforward and fast installing the thermowell without support collar, and thus without expensive and time-consuming rework on site.
This helical design has been used successfully for many years in a wide variety of industrial applications to effectively suppress vortex-induced shrinkage excitation.
In certain flow conditions, a Kï¿½rmï¿½n vortex street can form behind the thermowell stem when it is 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, which can instigate the thermowell to vibrate.
NEW ScrutonWell ï¿½ design
The helical strakes, arranged around the thermowell stem of the ScrutonWell ï¿½ design, split up the flow and therefore impede the forming of a clearly defined Kï¿½rmï¿½n vortex street. Through the reduced amplitudes of the diffused vortices, vibrational excitation of the thermowell is avoided.
ไดอะแฟรม ScrutonWell ï¿½ design may be used for all kind of solid machined thermowells with flange connection, in Vanstone design or for weld-in or screwed process connection.
Further information on our thermowells can be found on the WIKA website.
Learn more about the new ScrutonWellï¿½ design in the next video: