IA Pumping Systems & Pump Selection

Question 1

Total Dynamic Head (TDH) in a pump system is the sum of which components?

Accepted Answer

Static head + friction losses + velocity head + pressure head at discharge

Answer

Flow rate + pipe diameter + elevation

Answer

Pump horsepower + motor efficiency

Answer

Operating pressure + static water level only

Question 2

On a centrifugal pump curve, what is the 'best efficiency point' (BEP)?

Accepted Answer

The point on the pump curve where the pump operates at its highest efficiency

Answer

The maximum flow rate on the curve

Answer

The shutoff head with zero flow

Answer

The intersection of the pump curve and system curve

Question 3

Cavitation in a centrifugal pump is caused by:

Accepted Answer

Low suction pressure causing liquid to vaporize inside the pump

Answer

Excessive discharge pressure

Answer

Over-lubrication of pump bearings

Answer

Impeller running at too low a speed

Question 4

Net Positive Suction Head Available (NPSHa) must always be:

Accepted Answer

Greater than NPSHr (required) to prevent cavitation

Answer

Equal to total dynamic head

Answer

Less than NPSHr to maximize flow

Answer

Equal to static suction lift

Question 5

Which type of pump is most commonly used in municipal and agricultural irrigation mainline applications?

Accepted Answer

Centrifugal pump

Answer

Gear pump

Answer

Diaphragm pump

Answer

Peristaltic pump

Question 6

Brake horsepower (BHP) of a pump is calculated using which formula?

Accepted Answer

BHP = Flow (GPM) × TDH / 3,960 × pump efficiency

Answer

BHP = Voltage × Amperage

Answer

BHP = TDH × pipe diameter

Answer

BHP = Flow (GPM) / pressure (PSI)