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[2nitin2]

How to adjust the pressure in centrifugal pump ? detailed process pls.

thanx.

[Saurabh Sharma]

If you want to adjust the pressure, firstly you can refer the Q-H curve of the pump. As the dishcarge of the pump is decreased, the pressre or head generated increases and goes upto a maximum value called as the shut-off head where the discharge actually becomes zero. So, you can adjust the pressure by varying the discharge of the pump using a control valve in the discharge line of the pump.
But, if you want that the pressure is increased and the pump still delivers the same amount of fluid, then you will need to make some major changes:
1) Firstly, if the driving motor is a variable speed motor, then you can change the speed of the motor (and hence, the pump) to change the pressure. (Or you can change the motor itself) According to pump affinity laws ,
     Discharge is directly proportional to speed
     Head is directly proportional to square of speed
     Power is directly proportional to cube of speed.
By changing the speed of rotation, you can offset the whole Q-H curve of the pump
2) Second, the head can also be changed by changing the outlet dia of the pump. But for achieving this you will need to change or modify the impeller of the pump. According to the affinity laws,
     Discharge is directly proportional to dia
     Head is directly proportional to square of dia
     Power is directly proportional to cube of dia
I hope this will help you.
Regards,

2nitin2, on 30 August 2010 - 02:56 PM, said:

How to adjust the pressure in centrifugal pump ? detailed process pls.

thanx.