WIKA

ScrutonWell®

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.

FAQ

Why do some users want a polished thermowell surface, while others prefer a very rough surface, or knurling, of the area making contact with the flow?

A polished surface has greater corrosion resistance than a rough surface, due to its having less surface area. However, a knurled texture mitigates the vibrational excitation caused by a Kármán vortex street. Since strong vortices lead to mechanica ...

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