**Cavitation:**
> > * The vapour pressure of a liquid may be defined as pressure at which the liquid will transform into vapour (liquid boils) at the given temperature and vapour pressure is function of temperature.
> > * Care should be taken that pressure at any point does not fall below the vapour pressure of liquid to be pumped.
> > * If pressure in the pumping system falls below vapour pressure of the liquid to be pumped, then some of the liquid flashes into vapour or if the liquid contains gases, they may come out of the solution resulting into gas pocket, that damage the impeller. This phenomena is known as _cavitation._
> > * The vapour pressure of a liquid may be defined as pressure at which the liquid will transform into vapour (liquid boils) at the given temperature and vapour pressure is function of temperature.
> > * Care should be taken that pressure at any point does not fall below the vapour pressure of liquid to be pumped.
> > * If pressure in the pumping system falls below vapour pressure of the liquid to be pumped, then some of the liquid flashes into vapour or if the liquid contains gases, they may come out of the solution resulting into gas pocket, that damage the impeller. This phenomena is known as _cavitation._
**Effect of Caviation**
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> * Sufficient suction head is not developed that results in on pumping of liquid.
> > * Mechanical damage to the pumps occurs as bubble collapse.
> > * Considerable noise and vibration is produced.
> > * Decrease efficiency of pump. How to Minimize Cavitation ? > > > * By keeping the velocity of liquid in the suction pipe as minimum as possible. > > * Avoid sharp bends in the suction pipe, that will reduce loss of head. > > * The cavitation will not take place, if the total head vapour pressure of liquid is water then the absolute pressure head should not be below 2.5 m of water. > > * Cavitation resistant material or coatings such as aluminium, bronze, stainless steel should be used. >
> > * Mechanical damage to the pumps occurs as bubble collapse.
> > * Considerable noise and vibration is produced.
> > * Decrease efficiency of pump. How to Minimize Cavitation ? > > > * By keeping the velocity of liquid in the suction pipe as minimum as possible. > > * Avoid sharp bends in the suction pipe, that will reduce loss of head. > > * The cavitation will not take place, if the total head vapour pressure of liquid is water then the absolute pressure head should not be below 2.5 m of water. > > * Cavitation resistant material or coatings such as aluminium, bronze, stainless steel should be used. >
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