Industrial-process control valves. Noise considerations Laboratory measurement of noise generated by hydrodynamic flow through control valves

2Scope / Description

IEC 60534-8 This part includes methods for measuring the sound pressure level generated by liquid flow through control valves, and methods for determining the increase in noise characteristics due to cavitation onset. It also defines the equipment, methods, and procedures required for laboratory measurements to determine these characteristics of airborne sound. Two methods for testing the noise generation characteristics of control valves are provided. The first is a unified method for measuring the radiated noise of the valve and its associated test piping (including the fixed flow restriction through which the fluid (water) passes). The noise standard is expressed by determining the sound pressure level of the associated valve. The second is a procedure for measuring the sound pressure level in the upstream and downstream piping system of the valve under fixed operating conditions. This method should be preferred for evaluating the acoustic characteristics of valves because it eliminates the inaccuracies introduced by piping transmission. The noise characteristics to be determined have a wide range of applications: a) determining the acoustic characteristics of valves and valve assemblies, and the characteristic pressure ratio coefficient xFz of control valves; b) predicting valve noise under given process conditions; c) comparing the performance of different valves and various measurement results; d) planning measures to increase service life and reduce noise; e) identifying potential adverse effects on ultrasonic flowmeter measurements; f) appropriately selecting the size of silencers. Note 1: Test fluids other than water or valves without downstream piping are not covered in this part of IEC 60534-8. Note 2: The coefficient xFz is used in the noise prediction method, which is covered in IEC 60534-8-4.