JET 03 Centrifugal Pumps

Question 1

____________ is the rotating element through which liquid passes in a centrifugal pump?

Answer 1

impeller

Question 2

Wear rings serve the same function as

wear plates.

Answer 2

TRUE

Question 3

Which of the following is used to make
fine adjustments to the clearance between
the plates and impeller?

Answer 3

shims

Question 4

Bearings support the shaft.

Answer 4

TRUE

Question 5

Which of the following drive mechanisms
are used for the Schlumberger centrifugal
pumps? Select four that apply.

Answer 5

A. power-takeoff
B. hydraulic
C. electric
D. diesel

Question 6

How do centrifugal pumps convert

mechanical energy into hydraulic energy?

Answer 6

by pushing fluid into the system

Question 7

How does the volute affect the velocity of

energy of the liquid?

Answer 7

converts it into pressure

Question 8

Total head can be increased by increasing

the rpm.

Answer 8

TRUE

Question 9

Bearings support the shaft.

Answer 9

TRUE

Question 10

Which of the following lubricate bearings?

Select two that apply.

Answer 10

A. oil bath

C. grease

Question 11

A centrifugal pump primes itself.

Answer 11

FALSE

Question 12

Worn packing can cause the seal to fail.

Answer 12

TRUE

Question 13

Rope packing is used in RB23 centrifugal

pumps.

Answer 13

TRUE

Question 14

Centrifugal pumps that use mechanical
seals are _________, _________, and
_________.

Answer 14

A. RA 4x5
B. RA 5x6
D. RB 2x3x11

Question 15

Total suction head is the difference
between the levels of the discharge and
suction liquid.

Answer 15

FALSE

Question 16

To minimize vortexing, perform which of
the following (select three that apply):

Answer 16

A. Install crossbars in the suction of the
pump and tank.
C. Lower the pump rate.
D. Float a large piece of wood over the
suction opening in the tank.

Question 17

The pressure within the pump must not fall
below the vapour pressure of the liquid at
the pumping temperature.

Answer 17

TRUE

Question 18

To increase NPSH-A _________ ,

_________, and _________ .

Answer 18

A. Raise the liquid level.
B. Lower the pump.
D. Use a booster pump.

Question 19

An operation is parallel when the
discharge sides of two pumps are
connected to the same outlet.

Answer 19

TRUE

Question 20

You can operate centrifugal pumps

continuously near shutoff or zero capacity.

Answer 20

FALSE

Question 21

Pumping liquid that contains abrasive

particles does not cause erosion.

Answer 21

FALSE

Question 22

Air is mixed in the liquid being pumped as

a result of (select all that apply):

Answer 22

A. leaky suction lines
B. improperly assembled stuffing box
C. inadequate seals on the suction lift
hook-up

Question 23

Series operations are not recommended
because of the high incidence of seal
failures in the second pump.

Answer 23

TRUE

Question 24

When rigging up the centrifugal pump,

take into consideration _________.

Answer 24

A. rate
B. distance
C. pressure
D. viscosity of the fluid