Eight solutions for adjusting valve vibration

If the vibration phenomenon occurs during the use of the regulating valve, Shanghai Bozhou, as a professional manufacturer of regulating valves, proposes eight solutions for you, as follows:

1, increase the stiffness method: the oscillation and slight vibration, can increase the stiffness to eliminate or weaken, such as the use of large spring stiffness, the use of piston actuators and other methods are feasible.

2, increase the damping method: increase the damping that increases the vibration of the friction, such as sleeve valve plug can be used "O" ring seal, using graphite filler with a large friction, etc., which eliminate or weaken the slight vibration Still have a role.

3, increase the guide size, reduce the fit clearance method: the general shape of the plug-shaped valve size is small, all valves with a large gap generally have 0.4 ~ 1mm, which is helpful to produce mechanical vibration. Therefore, when a slight mechanical vibration occurs, the vibration can be weakened by increasing the guide dimension and reducing the fit clearance.

4, to change the shape of the throttle, to eliminate the resonance method: Because the so-called vibration source of the control valve occurs in the high-speed flow, the throttle pressure changes rapidly, change the shape of the throttle can change the frequency of the vibration source, when the resonance is not strong It is easier to solve. The specific method is to turn the surface of the valve core within the range of vibration opening by 0.5 to 1.0 mm. If a manufacturer has installed a self-operated pressure regulating valve near the company's property area, the resonance generated a whistle and affected the rest of the staff. After the 0.5 mm displacement of the slider surface, the resonance whistling noise disappeared.

5. Replacing throttling parts to eliminate resonance: If a nitrogen fertilizer plant has a DN25 double seat valve, the connection between the valve stem and the valve core is often vibrated. After we confirm it as a resonance, we will change the linear characteristic spool to a logarithmic spool. The problem was solved. Another example is the use of a DN200 sleeve valve in an academy's laboratory. The valve plug produces a strong rotation and cannot be used. After the windowed sleeve is changed to a sleeve with a small hole, the rotation immediately disappears.

6, replace the type of control valve to eliminate resonance: different structure of the control valve, its natural frequency is different, replace the type of control valve is fundamentally eliminate the resonance of the most effective method. Resonance of a valve in use is very powerful - vibrate strongly (in case of severe damage to the valve), strongly rotate (even the valve stem is broken, broken), and generate a strong noise (up to more than 100 decibels) The valve, as long as it is replaced with a valve with a large structural difference, will immediately take effect and the strong resonance will disappear miraculously. For example, if a DN200 sleeve valve is used in a new expansion project of the Vinylon plant, all three phenomena mentioned above will occur. The DN300's pipe will jump, the valve plug will rotate, the noise will be more than 100 decibels, and the resonance opening will be 20 to 70%. Consider resonant opening. When it was too big, after using a two-seat valve, the resonance disappeared and it was put into operation.

7. Reducing the cavitation vibration method: The cavitation vibration generated by the collapse of cavitation bubbles should naturally be considered in terms of reducing cavitation. The impact energy generated by the collapse of the bubble does not act on the solid surface, especially the valve plug, but rather allows the liquid to absorb it. The sleeve valve has this feature, so it is possible to change the plug-type spool to a sleeve type. Take all the measures to reduce cavitation, such as increasing throttling resistance, increasing the pressure of the reducing orifice, grading or decompression in series.

8, to avoid the vibration source wave method: external vibration source vibration caused by valve vibration, which is obviously the normal work of the regulator valve should be avoided, if this vibration occurs, it should take appropriate measures. (Text / BOZHOU)