403 - Pumps

Question 1

Two types of pumps

Answer 1

Positive displacement pumps

Non-Positive displacement pumps

Question 2

Types of positive displacement pumps

Answer 2

Reciprocating pumps

Rotary pumps

Question 3

Types of reciprocating pumps

Answer 3

Piston pumps
Plunger pumps
Diaphragm pumps

Question 4

Types of rotary pumps

Answer 4

Progressive cavity
Sliding vane
Lobe
Gear
Peristaltic
Screw

Question 5

Progressing cavity

Answer 5

Rolls liquid
Very thick liquid
3 stages of rotor and cavity
Solid size smaller than opening
Takes up a large amount of space and is expensive
Very gentle pumps

Question 6

Progressive cavity advantages:

Answer 6

Self-priming/Suction lift
Ability to vary capacity
Non-pulsating flow
Generates high pressure due to staging
Abrasive fluids
Handles high viscosity

Question 7

Progressive cavity disadvantages:

Answer 7

Can’t run dry
Length of pump
Large foot print

Question 8

Sliding vane pump

Answer 8

Unbalanced design
Allows for reverse flow, but need to reverse the check valve
Seals very well

Question 9

Sliding vane pump advantages

Answer 9

Self-priming/Suction lift
Ability to vary capacity
Run dry for a short time
Handles low viscosities

Question 10

Sliding vane pump disadvantages

Answer 10

Abrasive solids damage pump
Medium pressure capabilities
Material limitations
Not suitable for high viscosities

Question 11

Lobe or Cam pump

Answer 11

Lobes don’t transfer power by touching each other, gears on the outside do that.

Question 12

Lobe pump advantages

Answer 12

Self-priming/Suction lift
Ability to vary capacities
Reversible
Handles high viscosities

Question 13

Lobe pump disadvantages

Answer 13

Abrasive resistance
Pressure capabilities
Stuffing box
Jamming
Pump efficiency
Non-pulsating flow

Question 14

External gear pump

Answer 14

Also known as trash pump

Becoming less common

Question 15

External gear pump advantages

Answer 15

Self-priming/Suction lift
High speed
Ability to vary capacity
Non-pulsating pump (depends on the speed)
Run dry for a short time
High temperature

Question 16

External gear pump disadvantages

Answer 16

High pressure causes slip
No solids allowed
Abrasion
High shear
Low viscosity fluids

Question 17

Internal gear pump

Answer 17

Very common

Similar to external gear pumps

Question 18

Internal gear pump advantages

Answer 18

Ideal for high viscosity liquids
Constant non-pulsating flow
Self-priming/Suction lift
Low NPSH required

Question 19

Internal gear pump disadvantages

Answer 19

High pressure causes slip
No solids 
Not abrasive resistant
High shear, metal to metal contact 
Low viscosity fluids

Question 20

Screw pump

Answer 20

Not as common
Screws don’t touch
Very fast and very high volume

Question 21

Screw pump advantages

Answer 21

Non-contacting
Non-pulsating flow
Run dry for a short time
High flow and high pressure

Question 22

Screw pump disadvantages

Answer 22

Solids
Abrasions
High shear
Low viscosities fluids

Question 23

Peristaltic pump

Answer 23

Pulse type

Medical industry

Question 24

Peristaltic pump advantages

Answer 24

Self-priming/Suction lift
Ability to vary capacity 
Handles "difficult" fluid
Reversible 
Can run dry
No seals

Question 25

Peristaltic pump disadvantages

Answer 25

``` Pressure Temperature Short hose life Pulsation High HP requirement Less efficient ```

Question 26

Air diaphragm pump

Answer 26

Valve goes back and forth due to differential pressure. | Real simple

Question 27

Air diaphragm pump advantages

Answer 27

``` Self-priming/Suction lift Ability to vary capacity Handles abrasive and suspended solids Handles viscous liquids Run dry Length of pump No seals Submersible No efficiency loss due to air ```

Question 28

Air diaphragm pump disadvantages

Answer 28

``` Pressure Noise Pulsation Limited by air flow and compressor Power consumption ```

Question 29

Types of Non-Positive displacement pumps

Answer 29

Centrifugal pump Volute pump Diffuser pump Concentric volute pump

Question 30

Centrifugal pump

Answer 30

Pressure creating device Converts velocity energy to pressure energy Flow depends upon system characteristics

Question 31

Volute pump designs:

Answer 31

Radial design Mixed flow Axial flow

Question 32

Diffuser pump designs

Answer 32

Vertical turbine | Horizontal

Question 33

Concentric volute designs

Answer 33

Regenerated turbine High speed Radial vane Recessed impeller

Question 34

Part A

Answer 34

Negative pressure inside the pumps pushes the fluid to the inside is the pump.

Question 35

Part B

Answer 35

The impellers coverts velocity energy to pressure energy.

Question 36

Part C

Answer 36

The fluid is at a maximum pressure energy.

Question 37

Part D

Answer 37

The fluid leaves the impellers after reaching a max pressure energy.

Question 38

Part E

Answer 38

The fluid is being discharged from the pump.