1. Q: What is the primary function of a pump? ANSWER To convert
mechanical energy into hydraulic energy to move fluids from one
location to another.
2. Q: What does TDH stand for in pump terminology? ANSWER Total
Dynamic Head - the total equivalent height that a fluid is to be pumped,
taking into account friction losses and pressure.
3. Q: What is the difference between positive displacement and
centrifugal pumps? ANSWER Positive displacement pumps move fluid
by trapping a fixed amount and forcing it through, while centrifugal
pumps use rotational energy to move fluid.
4. Q: What is cavitation in pumps? ANSWER The formation and
collapse of vapor bubbles in a pump due to low pressure, which can
damage pump components.
5. Q: What does NPSH stand for? ANSWER Net Positive Suction Head -
the pressure available at the pump suction to prevent cavitation.
6. Q: What is the difference between NPSH available and NPSH
required? ANSWER NPSH available is the actual suction head at the
pump, while NPSH required is the minimum needed to prevent
cavitation. Available must exceed required.
7. Q: What is static head? ANSWER The vertical distance the pump must
lift the liquid, measured from the source to the discharge point.
8. Q: What is friction head loss? ANSWER The pressure loss due to
friction as fluid flows through pipes, fittings, and valves.
,9. Q: What is a pump curve? ANSWER A graphical representation
showing the relationship between flow rate and head for a specific pump
at a constant speed.
10.Q: What is BEP in pump terminology? ANSWER Best Efficiency
Point - the flow rate at which the pump operates most efficiently.
11.Q: What is specific gravity? ANSWER The ratio of a liquid's density
compared to water at standard conditions (water = 1.0).
12.Q: How does specific gravity affect pump performance? ANSWER It
affects the horsepower required but does not change the head or flow rate
capacity.
13.Q: What is viscosity? ANSWER A measure of a fluid's resistance to
flow or internal friction.
14.Q: What is meant by pump displacement? ANSWER The volume of
liquid transferred per revolution or cycle of the pump.
15.Q: What is a volute in a centrifugal pump? ANSWER The spiral-
shaped casing that converts velocity energy to pressure energy.
16.Q: What is an impeller? ANSWER The rotating component of a
centrifugal pump that imparts energy to the fluid.
17.Q: What is a closed impeller? ANSWER An impeller with shrouds on
both sides of the vanes, used for clean liquids and high efficiency.
18.Q: What is an open impeller? ANSWER An impeller with vanes
attached to a central hub with no shrouds, used for liquids with solids.
19.Q: What is priming a pump? ANSWER Filling the pump casing and
suction line with liquid to remove air before starting.
20.Q: Why must centrifugal pumps be primed? ANSWER Because they
cannot compress air effectively and will not create enough suction to
draw liquid if filled with air.
21.Q: What is a self-priming pump? ANSWER A pump designed to
automatically evacuate air from the suction line and prime itself.
22.Q: What is a multistage pump? ANSWER A pump with two or more
impellers arranged in series to achieve higher heads.
23.Q: What is pump efficiency? ANSWER The ratio of hydraulic power
output to mechanical power input, expressed as a percentage.
, 24.Q: What is water hammer? ANSWER A pressure surge caused by
sudden changes in fluid velocity, typically from quickly closing valves.
25.Q: What is the minimum burial depth for water lines in Texas to
prevent freezing? ANSWER Generally 18-24 inches, though local
codes may vary.
26.Q: What is the purpose of a check valve in a pump system?
ANSWER To prevent reverse flow and maintain prime in the pump and
suction line.
27.Q: What is a foot valve? ANSWER A type of check valve installed at
the bottom of the suction line to maintain prime.
28.Q: What is suction lift? ANSWER The vertical distance from the liquid
source below the pump centerline to the pump.
29.Q: What is the maximum practical suction lift for water at sea level?
ANSWER Approximately 25 feet, accounting for atmospheric pressure
and friction losses.
30.Q: What is a flooded suction? ANSWER When the liquid source is
above the pump centerline, creating positive pressure at the suction.
31.Q: What does GPM stand for? ANSWER Gallons Per Minute - a
common measure of flow rate.
32.Q: What does PSI stand for? ANSWER Pounds per Square Inch - a
measure of pressure.
33.Q: How do you convert feet of head to PSI? ANSWER Divide feet of
head by 2.31 (for water). Example: 100 feet ÷ 2.31 = 43.3 PSI.
34.Q: How do you convert PSI to feet of head? ANSWER Multiply PSI
by 2.31 (for water). Example: 50 PSI × 2.31 = 115.5 feet.
35.Q: What is velocity head? ANSWER The energy of a fluid due to its
velocity, expressed in feet of head.
36.Q: What is the formula for horsepower in pump calculations?
ANSWER HP = (GPM × Head × Specific Gravity) ÷ (3960 × Efficiency)
37.Q: What is brake horsepower (BHP)? ANSWER The actual
horsepower required at the pump shaft to operate the pump.
38.Q: What is the typical speed of standard electric motors? ANSWER
1750 RPM for 4-pole motors or 3500 RPM for 2-pole motors at 60 Hz.
mechanical energy into hydraulic energy to move fluids from one
location to another.
2. Q: What does TDH stand for in pump terminology? ANSWER Total
Dynamic Head - the total equivalent height that a fluid is to be pumped,
taking into account friction losses and pressure.
3. Q: What is the difference between positive displacement and
centrifugal pumps? ANSWER Positive displacement pumps move fluid
by trapping a fixed amount and forcing it through, while centrifugal
pumps use rotational energy to move fluid.
4. Q: What is cavitation in pumps? ANSWER The formation and
collapse of vapor bubbles in a pump due to low pressure, which can
damage pump components.
5. Q: What does NPSH stand for? ANSWER Net Positive Suction Head -
the pressure available at the pump suction to prevent cavitation.
6. Q: What is the difference between NPSH available and NPSH
required? ANSWER NPSH available is the actual suction head at the
pump, while NPSH required is the minimum needed to prevent
cavitation. Available must exceed required.
7. Q: What is static head? ANSWER The vertical distance the pump must
lift the liquid, measured from the source to the discharge point.
8. Q: What is friction head loss? ANSWER The pressure loss due to
friction as fluid flows through pipes, fittings, and valves.
,9. Q: What is a pump curve? ANSWER A graphical representation
showing the relationship between flow rate and head for a specific pump
at a constant speed.
10.Q: What is BEP in pump terminology? ANSWER Best Efficiency
Point - the flow rate at which the pump operates most efficiently.
11.Q: What is specific gravity? ANSWER The ratio of a liquid's density
compared to water at standard conditions (water = 1.0).
12.Q: How does specific gravity affect pump performance? ANSWER It
affects the horsepower required but does not change the head or flow rate
capacity.
13.Q: What is viscosity? ANSWER A measure of a fluid's resistance to
flow or internal friction.
14.Q: What is meant by pump displacement? ANSWER The volume of
liquid transferred per revolution or cycle of the pump.
15.Q: What is a volute in a centrifugal pump? ANSWER The spiral-
shaped casing that converts velocity energy to pressure energy.
16.Q: What is an impeller? ANSWER The rotating component of a
centrifugal pump that imparts energy to the fluid.
17.Q: What is a closed impeller? ANSWER An impeller with shrouds on
both sides of the vanes, used for clean liquids and high efficiency.
18.Q: What is an open impeller? ANSWER An impeller with vanes
attached to a central hub with no shrouds, used for liquids with solids.
19.Q: What is priming a pump? ANSWER Filling the pump casing and
suction line with liquid to remove air before starting.
20.Q: Why must centrifugal pumps be primed? ANSWER Because they
cannot compress air effectively and will not create enough suction to
draw liquid if filled with air.
21.Q: What is a self-priming pump? ANSWER A pump designed to
automatically evacuate air from the suction line and prime itself.
22.Q: What is a multistage pump? ANSWER A pump with two or more
impellers arranged in series to achieve higher heads.
23.Q: What is pump efficiency? ANSWER The ratio of hydraulic power
output to mechanical power input, expressed as a percentage.
, 24.Q: What is water hammer? ANSWER A pressure surge caused by
sudden changes in fluid velocity, typically from quickly closing valves.
25.Q: What is the minimum burial depth for water lines in Texas to
prevent freezing? ANSWER Generally 18-24 inches, though local
codes may vary.
26.Q: What is the purpose of a check valve in a pump system?
ANSWER To prevent reverse flow and maintain prime in the pump and
suction line.
27.Q: What is a foot valve? ANSWER A type of check valve installed at
the bottom of the suction line to maintain prime.
28.Q: What is suction lift? ANSWER The vertical distance from the liquid
source below the pump centerline to the pump.
29.Q: What is the maximum practical suction lift for water at sea level?
ANSWER Approximately 25 feet, accounting for atmospheric pressure
and friction losses.
30.Q: What is a flooded suction? ANSWER When the liquid source is
above the pump centerline, creating positive pressure at the suction.
31.Q: What does GPM stand for? ANSWER Gallons Per Minute - a
common measure of flow rate.
32.Q: What does PSI stand for? ANSWER Pounds per Square Inch - a
measure of pressure.
33.Q: How do you convert feet of head to PSI? ANSWER Divide feet of
head by 2.31 (for water). Example: 100 feet ÷ 2.31 = 43.3 PSI.
34.Q: How do you convert PSI to feet of head? ANSWER Multiply PSI
by 2.31 (for water). Example: 50 PSI × 2.31 = 115.5 feet.
35.Q: What is velocity head? ANSWER The energy of a fluid due to its
velocity, expressed in feet of head.
36.Q: What is the formula for horsepower in pump calculations?
ANSWER HP = (GPM × Head × Specific Gravity) ÷ (3960 × Efficiency)
37.Q: What is brake horsepower (BHP)? ANSWER The actual
horsepower required at the pump shaft to operate the pump.
38.Q: What is the typical speed of standard electric motors? ANSWER
1750 RPM for 4-pole motors or 3500 RPM for 2-pole motors at 60 Hz.
