ISA 75.17

Control Valve Aerodynamic Noise Prediction

Published by	Publication Date	Number of Pages
ISA	04/01/1989	32

Category: ISA

ISA 75.17 – Control Valve Aerodynamic Noise Prediction

This standard establishes a method to predict the noise generated in a control valve of standarddesign by the flow of compressible fluid and the resulting noise outside of the pipe anddownstream of the valve. The transmission loss ( TL) equations are based on a rigorous analysisof the interaction between the sound waves that exist in the pipe and the many coincidencefrequencies in the pipe wall. Commercial pipe specifications allow a relatively wide tolerance inpipe wall thickness. This limits the value of the very complicated mathematical methods requiredfor a rigorous analysis; calculations prove that a simplified expression is justified.The equations in this standard make use of the valve sizing factors defined in ANSI/ISA-S75.01and ANSI/ISA-S75.02.This method was developed from the fundamental principles of acoustics, fluid mechanics, andmechanics.