Regulator valve noise solution

1 control valve to eliminate resonance noise method

Only when the control valve resonates, can there be superimposed energy and produce a loud noise of more than 100 decibels. Some have strong vibrations, little noise, some weak vibrations, and very loud noises; some have large vibrations and noise. This noise produces a monotonic sound that typically has a frequency of 3000-7000 Hz. Obviously, with the elimination of resonance, noise naturally disappears. For methods and examples, see 4), 5), and 6) in 4.5 above.

2 control valve to eliminate cavitation noise

Cavitation is the main source of fluid dynamic noise. When cavitation occurs, bubbles burst to generate high-speed impacts, causing strong local turbulence and cavitation noise. This noise has a wide frequency range, creating a rattling sound that is similar to the sound produced by gravel in fluids. Eliminating and reducing cavitation is an effective way to eliminate and reduce noise.

3 Use thick-walled pipe method

The use of thick-walled tubes is one of the sound path treatment methods. The use of thin walls can increase the noise by 5 dB, and the use of thick-walled tubes can reduce the noise by 0-20 dB. The thicker the same pipe wall, the larger the pipe diameter of the same wall thickness, the better the noise reduction effect. Such as DN200 pipeline, the wall thickness were 6.25,6.75,8,10,12.5,15,18,20,21.5mm, can reduce the noise were -3.5, -2 (that is, increase), 0,3,6, 8,11,13,14.5 dB. Of course, the thicker the wall, the higher the cost.

4 control valve using sound-absorbing material method

This is also a more common and effective method of sound path processing. Sound-absorbing materials can be used to enclose the noise source and the post-valve line. It must be pointed out that because noise can be transmitted over long distances through fluid flow, where the sound-absorbing material is packaged and where the thick-walled pipe is used, the effectiveness of noise elimination ends. This method is suitable for situations where the noise is not very high and the pipeline is not very long, because it is a more expensive method.

5 series muffler method

This method is applicable to the silencing of aerodynamic noise, which can effectively eliminate the noise inside the fluid and suppress the noise level transmitted to the solid boundary layer. This method is effective and economical where the mass flow rate is high or the pressure drop ratio before and after the valve is high. Using an absorption type tandem muffler can significantly reduce noise. However, from an economical point of view, it is generally limited to attenuation of about 25 dB.

6 control valve soundproof box method

Noise barriers, houses, and buildings are used to isolate the noise sources so that the noise of the external environment can be reduced to an acceptable level.

7 series throttle method

When the pressure ratio of the regulating valve is high (P/P1≥0.8), the serial throttling method is used to distribute the total pressure drop on the fixed throttling element behind the regulating valve and the valve. If diffusers or porous restrictors are used, this is effective in reducing noise. In order to obtain excellent diffuser efficiency, the diffuser (shape and size of the solid) must be designed according to the installation conditions of each piece, so that the noise level generated by the valve and the noise level generated by the diffuser are the same.

8 use low noise valve

The low-noise valve gradually decelerates according to the flow path of the fluid passing through the valve core and valve seat (multi-channel, multi-channel) to avoid generating supersonic velocity at any point in the flow path. There are many types of low-noise valves of various structures (designed for special systems) for use when used. When the noise is not very large, the use of a low-noise sleeve valve can reduce the noise by 10 to 20 dB, which is an economical low-noise valve. Tenth, when the stability of the control valve is poor solution.