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Valve Frequently Asked Questions High Noise Level

Ningbo Fenfa Valve Co.,Ltd | Updated: Aug 14, 2017

  Valve Frequently Asked Questions High noise level

  One of the most obvious and most uncomfortable problems with valves is noise. For humans, noise can not only interfere with life, but also lead to permanent hearing loss and unsafe working environment. Studies have shown that long-term exposure to high levels of noise, the human hearing will be damaged. The hearing loss is progressive and irreversible, starting with a high frequency failure, and the top hearing continues to fail eventually leading to a lower frequency that will also fail, which affects the ability to listen to the normal language. When subjected to lower frequency noise, the function of human organs such as the heart or liver may also be affected. In addition, noise and associated vibrations can also affect valve performance and lead to fatigue in valve lines and adjacent equipment.

  In essence, when the vibration in the atmospheric pressure to produce a wide range of changes, will produce noise, and then as a noise to the ear drum. The eardrum is diffused at a speed of sound [it is 1100 ft / s (335 m / s) or 750 m / h (1200 km / h)]. The noise of the valve can be produced in many different ways, but the most common cause is the turbulence generated by the valve geometry and is caused by the spread of the downstream pipeline. In many cases, the noise does not spread by the valve body, because the valve body itself is rigid and strong.

  Process turbulence produces vibration of the valve or valve components. The noise is caused by vibrations caused by random pressure fluctuations in the valve assembly, or by vibrations caused by obstacles in the fluid collision stream, such as spool, valve discs, or other closing elements. When the closure element constantly impacts its guide, it will cause the noise of the explosion for a long time. Because its frequency level is lower than 1500Hz, it normally does not interfere with the observer. However, the explosion of these stem or shaft with a guide can damage the ultimate guide and seat surface. Another side benefit of the explosion of the valve part is the warning that the secondary turbulence produces a warning when turbulence is generated in the valve, so correction is necessary before the accident occurs. Vibration can also be caused by some valve parts or accessories that resonate at their natural frequencies, often found at lower noise levels (less than 100 dBA). This type of noise is characterized by a single tone or Weng Weng sound (frequency of 300 ~ 700Hz), it produces high levels of stress in the material, leaving the material fatigue and material weakening. The noise may also be caused by hydrodynamic or aerodynamic fluid sounds. For liquid handling, hydrodynamic noise is caused by turbulence of flow, cavitation and flash, or high velocity when the fluid passes through the contraction section. In short, the noise generated by the liquid stream does not produce a high level of noise and can be tolerated by the staff. In severe cavitation or flashing operations, the level of noise can reach a higher level must be altered by the process or the installation of anti-cavitation components in the valve for disposal.

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