Resolving a Piping Vibration Problem by Installing Viscous Damper Supports

Authors: Carlos Herrera Sierralta, Husain M. Muslim, Meshal T. Alsaiari, Daniel Fischer

Abstract:

The vast majority of piping vibration problems in the Oil & Gas industry are provoked by the process flow characteristics which are basically related to the fluid properties, the type of service and its different operational scenarios. In general, the corrective actions recommended for flow induced vibration in piping systems can be grouped in two major areas: those which affect the excitation mechanisms typically associated to process variables, and those which affect the response mechanism of the pipework per se. Where possible the first option is to try to solve the flow induced problem from the excitation mechanism perspective. However, in producing facilities the approach of changing process parameters might not always be convenient as it could lead to reduction of production rates or it may require the shutdown of the system. That impediment might lead to a second option, which is to modify the response of the piping system to excitation generated by the process flow. In principle, the action of shifting the natural frequency of the system well above the frequency inherent to the process always favours the elimination, or considerably reduces the level of vibration experienced by the piping system. Tightening up the clearances at the supports (ideally zero gap) and adding new static supports at the system, are typical ways of increasing the natural frequency of the piping system. However, only stiffening the piping system may not be sufficient to resolve the vibration problem, and in some cases, it might not be feasible to implement it at all, as the available piping layout could create limitations on adding supports due to thermal expansion/contraction requirements. In these cases, utilization of viscous damper supports could be recommended as these devices can allow relatively large quasi-static movement of piping while providing sufficient capabilities of dissipating the vibration. Therefore, when correctly selected and installed, viscous damper supports can provide a significant effect on the response of the piping system over a wide range of frequencies. Viscous dampers cannot be used to support sustained, static loads. This paper shows over a real case example, a methodology which allows to determine the selection of the viscous damper supports via a dynamic analysis model. By implementing this methodology, it is possible to resolve piping vibration problems by adding new viscous dampers supports to the system. The methodology applied on this paper can be used to resolve similar vibration issues.

Keywords: dynamic analysis, flow induced vibration, piping supports, turbulent flow, slug flow, viscous damper

References:

[1] Energy Institute, “Guidelines for the Avoidance of Vibration Induced Fatigue Failure in Process Pipe Work”, 2nd Edition, Energy Institute, London, U.K, 2008.
[2] George Antaki, “Piping and Pipeline Engineering”, Marcel Dekker, INC. New York• Basel, 2003. pp. 226.
[3] Darcy Q. Hou, Arris S. Tijsseling, and Zafer Bozkus , “Dynamic Force on an Elbow Caused by a Traveling Liquid, ASME Journal of Pressure Vessel Technology”, Vol. 136 / 031302-1, 2014, pp. 3.
[4] Carlos Herrera Sierralta, and Husain Al-Muslim, “Evaluating Piping Supports Modification to Mitigate Slug Flow Induced Vibration Utilizing Time-History/Response-Spectrum Approach in a Rich Amine Column 30 NPS Inlet Piping System”. ASME 68915 Proceedings of ASME 2021 Intentional Mechanical Engineering Congress and Exposition IMECE 2021.
[5] EDI Report 85-305, Engineering Dynamics Incorporated, Vibration in Reciprocating Machinery and Piping System, EDI, San Antonio, USA, 1985.
[6] American Society of Mechanical Engineers, ASME B31.3, Process Piping, 2020
[7] Vibration Insulation Terms and Methods VDI 2062, May 2011, pp-25.
[8] Barutzki, “Protection of Piping Systems Against Operational Vibration and Seismic Excitation By means of Viscoelastic Fluid Dampers”, 17WCEE, 2020.
[9] Fischer, “Improving Service Life and Safety of Piping Systems by the use of Viscous Dampers”, Barutzki, Middle East Static Convention, 2018