How does the pump performance vary with impeller diameter?

How does the pump performance vary with impeller diameter?

The results show that changing the diameter of a pump impeller affects the flow, head and input brake horsepower of the pump in different proportions. The centrifugal pump gives a high flow rate as the diameter of the impeller increases. The impeller of a centrifugal pump regulates the performance of the pump [4, 5].

How do you calculate head capacity of a pump?

1. IMPORTANT NOTES :
2. TOTAL HEAD CALCULATION:
3. Total Head = suction Head + Delivery Head. Suction Head calculation = Suction vertical Height ( From Foot valve to Pump Centre) + Horizontal pipe line used + No of Bend (or) Elbow used in suction pipe line.
4. Example :-
5. Actul. Runnin.
6. Actul Total Head. —-
7. Head Conversion. Feet.

What is the maximum suction head of a pump?

Because a perfect vacuum is never achieved and because some lift is lost to friction in the suction line, the maximum actual suction lift for a positive-displacement pump is approximately 22 ft. The maximum actual suction lift for a centrifugal pump is approximately 15 ft when pumping water from an open air tank.

What is positive suction head of a pump?

NPSH (Net Positive Suction Head) is a measure of the pressure experienced by a fluid on the suction side of a centrifugal pump. It is used to avoid running a pump under conditions which favour cavitation.

What is negative suction head of a pump?

When the liquid level in the sump is below the pump centerline, the pump is said to be installed under negative suction head or just negative head. The pump has to create a pressure below atmospheric so that atmospheric pressure can force the liquid to the pump.

What does suction head mean?

The head or height to which water can be raised on the suction side of the pump by atmospheric pressure.

What happen if NPSH is negative?

This pressure energy is referred to as Net Positive Suction Head. The NPSH is supplied from the system and is solely a function of the system design on the suction side of the pump. If the liquid is below the pump, this becomes a negative value.

How do you prevent pump cavitation?

How to Prevent Cavitation

1. Reduce motor speed (RPMs).
2. Install an impeller inducer.
3. Incorporate a booster pump into your pump system.
4. If possible, reduce the temperature of your pump, liquid, and/or other components.
5. Increase liquid level around the suction area.

What is NPSH pump curve?

The NPSH curve displays the minimum required inlet pressure (expressed in m) allowing the pump to pump in accordance with the performance curve and in order to prevent evaporation of the pumped fluid so as to avoid cavitation inside the pump.

How pump curves are generated?

Pumps can generate high volume flow rates when pumping against low pressure or low volume flow rates when pumping against high pressure. The possible combinations of total pressure and volume flow rate for a specific pump can be plotted to create a pump curve.

What happens when a pump runs off its curve?

If a pump is running out on the end of the curve it can cause cavitation inside the pump and result in premature wear of the impeller and bearings of the motor. It can also cause the motor to over amp and prematurely fail.

How long can a centrifugal pump run dry?

45-60 seconds

How does Suction Head affect pump performance?

Suction Head. These are two equal but opposite forces that affect the flow of water pumps. This is because the water entering the pump applies additional pressure at the suction. Conversely, if the pump is located above the water to be pumped, then the suction head is positive and the pump head will decrease.

How high can a pump lift water?

33.9 feet

What is the maximum suction pressure?

14.7 psi

What is maximum head lift?

Maximum Head Lift is the total height from the source of the water to the destination or drainage point. This provides the power to move water over a distance.