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Severe service control valves or better, high-pressure reducing valves can see inlet pressures in excess of 4000 psi. Such valves are found in industries ranging from gas or petroleum wells, to chemical plants and steam-producing power plants (Goodwin, “Specifying Control Valves for Severe Service Conditions”, INTECH FOCUS, November (2022), p. 20). Such valves convert high levels of kinetic energy through a process of conversion of sound-producing turbulence to a reduced pressure level. Less desired by-products such as conversion are sound pressure levels that can exceed 120 decibels, a sound that is comparable to standing next to a jet plane taking off. Part of this energy conversion manifests itself as mechanical vibration which can cause undesirable high pipe acceleration which, over time, could severely damage piping (Almasi. “Flow Induced Vibrations in Piping Systems”. P.I. PROCESS INSTRUMENTATION, July, 2020; Blake, 1986, “Mechanics of Flow Induced Sound and Vibrato,” Vol. II, Complex Flow-Structure Interactions, Academic Press, Orlando, FL). Proposed here is an easy computer programmable method to check the sound and acceleration levels associated with noisy valves. It is believed such a paper harmonizing all aspects of aerodynamic valve noise, such as sound pressure, sound power, vibration, and acceleration can be of value. The purpose of this paper is to explain how such acceleration levels are estimated. There are four steps involved: (1) calculate the sound pressure level (SPL) from given process data, (2) convert sound pressure level into sound power level (Lwi), and (3) find the associated maximum pipe internal peak frequency (fp). (4) Based on the sound power level and the peak frequency of the sound, calculate the acceleration of the pipe (in m/second2). |
