Hi everybody,

Can someone give me a brief explanation regarding with "CAVITATION" of pump and valves?

Thanks in advance,
Waiting for your reply,
nyeintinzar.

Cavitation - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Cavitation) is a good place to start. Maybe reading this will assist you in being able to find other more simpler explanations.

Because boiling point of water is directly proportional to the pressure at that region,,
When water flows in the pipe,if there is sudden enlargement in the cross sectional area of that pipe,pressure at that region drops suddenly and water evaporate at that time,,
When inside pressure increase ahead of pipe,
This vapour collpse and shock wave generate which create an errodic sound when it hits the inside surface of pipe,It errode that surface,
The phenomenon of collapsing is called CAVITATION,,
Hope u can understand easily,,

As per ASHRAE Cavitation is the creation of vapor pockets or flashing of water into vapor.

It happens when the fluid press inside the pump falls below the operating vapor pressure. The fluid flashes into bubbles. These bubbles are carried along until they reach a region of higher press within this region such as at the impeller the bubbles of gaseous will be reliquedfied and the bubles of air will be reabsorbed. This transition or collapse occurs suddenly and is accompanied by crackuing or explosive noises. The collapse can be destructive to the impeller

To eliminate cavitation :
- Decrease the friction loss
- change the elevation of the pump to increase the static head
- install throttling valve in the discharge pipe to reduce pump capacity.
- use higher velocity for water
- maintain a minimum suction pressure at the inlet side of the pump