Abstract: In order to explore the effect of hole shape and the structure of the throtting orificeplate on the pressure drop of pipelines and the noise generated by the vibration of the pipeline， the vibration and sound pressure level of four different throtting orificeplate in an anechoic chamber were studied. The mechanism of throtting orificeplate with different configurations were analyzed by numerical simulation. The results show that the mechanical energy loss of flow in throttle pipe with square hole shape is the largest， whose pressure drop is 12.6kPa bigger than that in the pipe with circular hole shape and the same opening. The stress amplitude and the sound pressure level of that pipe are both obviously higher than that of other three pipes. The throttling orificeplate with stepped hole can effectively raises the local minimum pressure of the fluid in the pipe and reduces the occurrence of cavitation， so the radiated sound pressure level of the pipe is the smallest.

Key words: throttling orificeplate, experimental analysis, theoretical calculation method and validation, throttling characteristic, acoustic characteristic