Method of determining sound power levels from valves controlling flow and pressure text London British Standards Institution 1984 monographic 12 p. Describes procedures for the determination of sound power levels of a hydraulic fluid power valve under controlled conditions of installation and operation, suitable for providing a basis for comparing the noise levels of valves. Flow regulators, Liquid valves, Cavitation, Free-field rooms, Hydraulically-operated devices, Hydraulic transmission systems, Sound intensity, Valves, Noise (environmental), Testing conditions, Acoustic measurement, Pressure regulators 0580137805