ScrutonWell® - Innovative design for the damping of vibrational excitation
Applications
- Petrochemical industry, on/offshore, plant construction
- For highest process loads
- Application in critical measuring points
Special features
- The damping of vibrational excitation by helical strakes is a recognised state of the art in a wide variety of industrial applications
- Easier and more cost-effective installation of the thermowell without any machining of the collar or nozzle compared to the conventional support of the thermowell with support collar
- Optimised root design for improved bending strength
Description
In order to avoid any damage to the thermowell during operation due to mechanical loads, a wake frequency calculation per ASME PTC 19.3 TW-2016 is recommended for critical process conditions. In case of a calculation with negative results, the only 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 only other alternative up to now was to use a support collar to stabilise the thermowell stem inside the flange nozzle. This variant required an on-site machining of the collar to assure an interference fit in flange nozzles.
The ScrutonWell® design reduces the amplitude of oscillation by more than 90 % 1) and allows an easy and fast installation of the thermowell without support collar, and thus without expensive and time-consuming rework on site.
The WIKA ScrutonWell® design has been tested and approved by the independent laboratories TÜV NEL (Glasgow) and the Institute for Mechanics and Fluid Dynamics (Technical University of Freiberg).
The ScrutonWell® design can be used for all kind of solid-machined thermowells with flange connection, in Vanstone design or for weld-in or threaded process connection.
This helical design has been used successfully for decades in a wide variety of industrial applications to effectively suppress vortex-induced vibration excitation.
1) Journal of Offshore and Mechanics and Artic Engineering Nov 2011, Vol 133/041102-1 by ASME
Discover also our wide product portfolio of WIKA thermowells and protection tubes.
Can the calculations per ASME PTC 19.3 TW-2016 be used for thermowells and protection tubes?
No. The calculation per ASME PTC 19.3 TW-2016 is only used for thermowells in tapered, straight or stepped designs from solid materials, such as Model TW10, TW15, TW20, etc.
What is the permissible minimum bending radius for an MI cable?
VDI/VDE 3511 Sheet 2 recommends a radius of curvature R of ≥ 5 x D (D=external diameter of the MI cable), some manufacturers of MI cable even give ≥ 3 x D as the minimum bending radius.
