Flow-induced sonic vibration in boiler safety valve nozzles led to premature valve wear and failure. The valves were mounted just downstream of a 1 1/2D pipe elbow, in contravention of guidelines suggesting an 8 to 10 diameter separation to avoid sonic vibrations. Initial modifications proved unsuccessful. A consultant then recommended replacing the cylindrical valve nozzles with reducers, which stopped the vibration. A review of flow-induced cavity vibrations is presented. In the case of the safety valves the vibration is believed due to fluid-dynamic instability of the cavity shear layer, enhanced and controlled by the resonant characteristics of the adjacent cavity. The precise feedback, or coupling, mechanism that sustains the oscillation is unknown. Possible reasons for the success of the tapered shape reducer are discussed. The limited design guidance available for safety valve placement is reviewed. Results of a safety valve vibration experience survey are presented and discussed. A two-parameter guideline for safety valve placement is suggested, involving steam velocity in addition to valve location. Possible future work on safety vibration is outlined.
Skip Nav Destination
Article navigation
February 1980
Research Papers
Failure of Safety Valves Due to Flow-Induced Vibration
J. T. Coffman,
J. T. Coffman
Oklahoma Gas and Electric Co., Oklahoma City, Okla. 73101
Search for other works by this author on:
M. D. Bernstein
M. D. Bernstein
Foster Wheeler Energy Corporation, Livingston, N. J. 07039
Search for other works by this author on:
J. T. Coffman
Oklahoma Gas and Electric Co., Oklahoma City, Okla. 73101
M. D. Bernstein
Foster Wheeler Energy Corporation, Livingston, N. J. 07039
J. Pressure Vessel Technol. Feb 1980, 102(1): 112-118 (7 pages)
Published Online: February 1, 1980
Article history
Received:
September 19, 1979
Online:
November 5, 2009
Citation
Coffman, J. T., and Bernstein, M. D. (February 1, 1980). "Failure of Safety Valves Due to Flow-Induced Vibration." ASME. J. Pressure Vessel Technol. February 1980; 102(1): 112–118. https://doi.org/10.1115/1.3263289
Download citation file:
Get Email Alerts
The Behavior of Elbow Elements at Pure Bending Applications Compared to Beam and Shell Element Models
J. Pressure Vessel Technol (February 2025)
Related Articles
Flow-Induced Vibration in Safety Relief Valves
J. Pressure Vessel Technol (August,1986)
Review—Self-Sustaining Oscillations of Flow Past Cavities
J. Fluids Eng (June,1978)
Leakage Flow-Induced Vibrations of Heat Exchanger Fins
J. Pressure Vessel Technol (November,1992)
Development and Application of a Complete Multijet Common-Rail Injection-System Mathematical Model for Hydrodynamic Analysis and Diagnostics
J. Eng. Gas Turbines Power (November,2008)
Related Proceedings Papers
Related Chapters
Lessons Learned: NRC Experience
Continuing and Changing Priorities of the ASME Boiler & Pressure Vessel Codes and Standards
Hydrodynamic Mass, Natural Frequencies and Mode Shapes
Flow-Induced Vibration Handbook for Nuclear and Process Equipment
Random Turbulence Excitation in Single-Phase Flow
Flow-Induced Vibration Handbook for Nuclear and Process Equipment