Centrifugal and Positive Displacement...

Centrifugal and Positive Displacement Pumps

1

Introduction

This iBook is part of a Program of Instruction (POI) on centrifugal and positive displacement pumps.

The first part explains the concept of c e n t r i f u g a l f o r c e a n d p o s i t i v e displacement.

The second part explains how pumps are classified as centrifugal and positive displacement machines.

In the third part you will extend your knowledge to identify the major parts of pumps and state their function.

2

Introduction

The oil and gas and petrochemical industry

This iBook introduces the learner to engineering equipment operating in on-shore and off-shore oil and gas installations.

A visual curricula model

The highly visual learning and teaching strategy uses interactive 3D animations and computer generated imagery to help you understand complex machines, systems and processes.

Ask the SME

A Subject Matter Expert (SME) is embedded into the content to explain difficult to understand ideas.

Concept first, then application

These images show how Bernouli’s principle is applied to the function of a centrifugal pump volute.You will be shown the concept first, then the engineering application

3

How to use this book - A visual curricula model

A visual curricula model

This iBook is populated with dynamic, informative and exciting 3D animations of machines, systems and processes.

Each animation is developed from a digital copy of a real machine to help you understand a complex idea or process.

You can review information by using the slider control to rewind and pause the animation.

You will be able to see hidden detail and navigate into areas that are impossible to observe in the real world.

Click on the play icon to see this animation of a radial piston pump

4

How to use this book - Tell a story with a visual curricula

Tell a visual story

This is a forced air fin fan cooler that is used to cool process liquids in the oil and gas industry.

This animation tells a visual story of the function and operation of the fin fan cooler.

You can use the slider to move through the animation to identify the major parts and see the flow of air and liquid through the cooler.

5


This is an induced air fin fan cooler.

You can scroll through these images to gain an understanding of its structure and function.

6


7

How to use this book - Complex machines made easy to understand

The operating principles of complex machines

Most machines, systems or processes appear difficult to understand when you are presented with complex technical terminology and 2D illustrations.

Traditional training resources rely on technical English language supported by static drawings, images and schematics.

This iBook flips that idea around and offers you a “Visual Curricula” model.

A visual curricula model is designed around the power of 3D models, animations and Computer Generated Imagery (CGI) to help you understand complicated ideas.

This animation is a great example of how 3D technology enables you to look inside a machine to gain a greater understanding of its working principle.

Enjoy watching this micro learning asset of a high pressure, swash plate, positive displacement, hydraulic pump.

8

How to use this book - Complex machines made easy to understand

The operating principles of complex machines

The internal components of this reciprocating compressor are shown in these dynamic animations.

You can see the crankshaft operating and the pistons reciprocating inside the cylinders.

This level of detail and clarity gives you a deeper understanding of the compressors operating principles.

9

How to use this book - Complex machines made easy to understandThe operating principles of complex machines

This animation of a twin screw hydraulic pump is a great example of the benefits of a visual curricula model.

The cut away casing enables you to see how the two screw shafts mesh together and gives you a greater understanding of the pumps operating principles.

The dramatic, perspective angle draws your interest into the machine and reveals the rotation of the bearings, shaft and twin screws.

10

How to use this book - Large structures viewable on a computer screen

Large structures

This is an industrial cooling tower used in the oil and gas and petrochemical industries.

3D Digital models allow you to navigate your way around large scale structures, plants and refineries in the safety of your computer or tablet environment.

These animations reveal the major design features of this cooling tower.

11

How to use this book - Large structures viewable on a computer screen

Large structures

You can gain an understanding of the construction of this cooling tower by watching this 360 degree animation.

12

How to use this book - Large structures fly through

Large structures

This fly through animation shows you the cooling tower’s fin fan blades, drive motor and gearbox.

13

How to use this book - Large installations

High Integrity Protection System (HIPS)

HIPS installations control well head systems from overpressure or under pressure conditions.

This HIPS installation is controlled by a system of hydraulic control and isolation valves.

This animation shows the complete HIPS system, further pages will show individual parts of the HIPS system.

14

The HIPS installation is monitored by a hydraulic control unit.

You can see the complex hydraulic pipework system and valves in these 3D images.

These graphics are created from an accurate replica of the HIPS installation in the field.

How to use this book - Large installations - individual parts

15


In an emergency shut down situation the HIPS installation is pressurized by a manual hydraulic pump.

The pump is shown in its operating position inside the control cabinet.

Select this animation to see how you will operate the hydraulic pump to pressurize the system.

The second animation shows the internal parts of the hydraulic pump.

16


You can see the open control cabinet in this image of the HIPS system.

The HIPS pressure regulator is identified with a blue handle.

Select the animation to see a section view that shows how the regulator operates.

17

How to use this book - Large installations - emergency operation simulation

This animation shows how the HIPS system operates in an emergency shut down situation.

You can see the sequence of operation of the sensors and valves that cause the reverse acting, hydraulically operated gate valve to shut down and stop the downstream flow of oil.

18

How to use this book - Complete systems - individual parts

Air conditioning (AC) system

Each component of an air conditioning system is represented in this 3D model.

Further pages will describe the operation and function of each part.

This is a 3D model positioned in a 2D viewpoint to represent a schematic drawing.

Further pages will show the individual parts as 3D animations and CGI.

19


Air Conditioning Solenoid Valve

Play this animation to see the parts and operation of an AC system solenoid valve.

20


Looking inside machines

This animation strips away the external casing of an AC compressor so you can see the rotating and reciprocating parts.

21

Flow Diagrams

This graphic represents a flow diagram of a gas compression system. Select the play button to see the flow path.

22

Flow Diagrams

You can select any image in this flow diagram and it will reveal an animation describing that part of the process.

23

Flow Diagrams

This graphic represents a flow diagram describing different types of positive displacement pumps.

You can select any image and it will reveal an animation describing the operating principles of the pump.

24

How to use this book - High resolution Computer Generated Imagery (CGI)

High resolution CGI

This iBook is built on a visual curricula model that includes authentic and photorealistic images.

This CGI of an impulse steam turbine is as an exact replica of the real machine.

25


26


High resolution CGI

This CGI of a gas turbine shows the compressor and turbine rotors and stators.

27


28


High resolution CGI

This CGI of a single stage centrifugal pump shows a section view of the impeller and volute casing.

29


High resolution CGI

You can see the detail of the ball bearings and roller bearings in this CGI of a twin screw positive displacement pump.

30

Play Full Screen

Click on this icon and the animation will enlarge to fill the screen. A control bar will appear to enable you to stop and rewind the animation.

Show Full Screen

Every graphic in this book is designed to enlarge to fill the screen. When you click on the thumbnail image it will enlarge so you can see the high resolution detail of the machine.

How to use this book - Icons - Animations - Graphics - SME - Pop Ups - 3D Models

31

How to use this book - Icons - Animations - Graphics - SME - Pop Ups - 3D Models

The Subject Matter Expert - SME

The SME icon provides you with specialist information about the subject under discussion. Think of this function as having your own personal expert, ready to answer those difficult to understand concepts.

Pop Ups

Pop ups appear on the page when you click on the blue text.

Pop ups contain further information or graphics to help you understand a particular point under discussion.

You will also see bold text, this feature emphasizes an important concept.

Pump Module 1.1 - Centrifugal Force

32

1.1.1 Describe the concept of centrifugal force.

1.1.2 Describe the function of the volute and impeller in a centrifugal pump.

Learning objectives

Learning Objective 1.1.1 - Describe the concept of centrifugal force.

33

This Mechanical Engineering Program of Instruction (POI) begins by introducing you to the concept of a machine, system or process.

When you have explored the concept you will be guided to investigate its real world application.

This part of the module reveals the relationship between centrifugal force and pressureand applies these concepts to a centrifugal pump.

34

Pump Module 1.1.1 - Centrifugal Force

Gravity and Centripetal Force

This part will introduced you to the concept of gravity and centripetal force by looking at the orbital relationship between the earth and the moon.

Centrifugal Force

This part will explain how centrifugal force is a fictitious event that is an equal and opposite reaction to centripetal force. You will examine Newton’s laws of motion to gain a deeper understanding of centrifugal force.

Speed and Pressure

This part will show how the impeller and volute work together to transform speed into pressure. This concept is fundamental to understanding how a centrifugal pump works.

35


Gravity and Centripetal Force

The moon is held in position around the earth by a force called gravity.

The gravitational force exerted by the earth on the moon is equal to the centripetal force.

Centripetal force is a center seeking force exerted on an object moving in a circular or elliptical path.

As the moon accelerates around its orbit a centripetal force is constantly pulling it toward the center of the earth.

If gravity suddenly stopped acting on the moon it would accelerate into space in a tangential straight line to the earth.

These concepts can help us understand the relationship between centripetal and centrifugal force when applied to a centrifugal pump.

This animation shows what happens when the moon looses its center seeking centripetal force.

36

Pump Module 1.1.1 - Centrifugal Force - SME

PLACE HOLDER AUDIO FILE

37

Newton’s laws of motion

Sir Isaac Newton was a 17th century English mathemat ic ian, phys ic is t , ast ronomer, theologian and author.

Newton formulated the laws of motion and universal gravitation that define the forces acting on a body and the motion of the body.

Newton’s first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at a constant speed unless it is acted upon by a force.

This is known as the law of inertia.

In our example of the moon orbiting the earth the center seeking force that acts on the moon and resists its tendency to move in a straight line is gravity.

This image illustrates the idea of gravity and centripetal force.

The following pages will apply Newton’s laws of motion to a centrifugal pump impeller.


38

Newton’s laws of motion

Newton’s first law is shown in this animation. the spherical body is moving in a straight line at a constant speed. In this situation no other forces are acting on the sphere.

In this example the sphere is connected to a center axis and is rotating in a circular path.

Centripetal forces are acting on the sphere, pulling it toward the centre of the axis and restricting it from moving in a straight line.

This animation shows what happens when the sphere is disconnected from the center axis.

Newtons first law is re-established and the sphere moves in a straight line tangential to the center axis.


39


Centrifugal Force - A Fictitious Force

As the sphere travels in orbit around the center axis a centripetal, center seeking force is exerted on it. This event is shown as an inward pointing green arrow in the animation.

Newton’s 3rd law states that every action has an equal and opposite reaction.

The reactive force that is equal and opposite in direction to centripetal force is shown as centrifugal force.

This event is shown as an outward pointing blue arrow in the animation.

Centrifugal force is a fictitious force and has the apparent effect of moving the sphere away from the center axis.

Inertia is the tendency of an object to move in a straight line at a constant speed.

It is the inertia of the sphere constrained to a circular path that generates the apparent centrifugal, center fleeing force.

40


Centrifugal Force

This is an impeller with a series of vanes that curve from its center to its edge.

As the impeller spins at high speed it transfers a centripetal force to the pumped liquid.

Centripetal force is a center seeking force and is shown as a green arrow in this animation.

Newton’s 3rd law states that every action has an equal and opposite reaction.

The opposite reaction force in this impeller example is called centrifugal force.

Centrifugal force is a center fleeing reaction and is shown as a blue arrow in this animation.

In this centrifugal pump example the centripetal force is not strong enough to keep the liquid traveling in a circular path with the impeller.

Centrifugal force overcomes centripetal force and the liquid accelerates across the vanes. The liquid is thrown in a tangential straight line to the volute and discharge pipework.

41


Speed and Pressure

This animation shows how the flow of liquid enters the center of the impeller and accelerates towards its edge. You can see how the liquid expands into the funnel shaped volute. The volute slows down the liquid and increases its pressure.

42


Speed and Pressure

The volute casing is a curved funnel that increases in area from the suction to the discharge flange of a centrifugal pump.

This animation shows the flow of liquid expanding into the volute casing.

You can see the impeller rotating inside the volute. The function of the impeller is to transfer speed to the pumped liquid.

The function of the volute is to convert the speed of the liquid into pressure.

The volute achieves this by enabling the liquid to expand into a larger area. When the liquid expands into the volute it decreases in speed and increases in pressure.

This animation shows a pressure gauge that indicates an increase in pressure at the discharge flange.

43


44

Pump Module 1.1.1 - Centrifugal Force - Summary

Summary

This part of the Mechanical Engineering Program Of Instruction (POI) examined centrifugal force and explored the following learning outcomes:

• Gravity and Centripetal Force

• Centrifugal Force

• Speed and Pressure

This POI will develop your knowledge of centrifugal force to help you understand the concept and function of a centrifugal pump.

You can work through the Centrifugal Force Review Questions to test your understanding of this part of the POI.

45

Pump Module 1.1.1 - Centrifugal Force Review Questions

Question Review 1.1.1 Centrifugal Force

Check Answer

Question 1 of 10Select the image that shows the Earth exerting a centripetal force on the Moon.

A. Answer 1

B. Answer 2

C. Answer 3

46

This is a single stage centrifugal pump.

In this part of the module you will see how the impeller increases the speed of the liquid flowing across its outwardly curved vanes.

The impeller spins at high speed and transfers a centrifugal force to the pumped liquid.

The impeller and volute function together to transform the speed of the liquid into pressure.

The volute is a funnel shape with a gradually increasing cross section from the suction to the discharge flange.

The volute enables the liquid to expand and slow down.

When the liquid slows down it increases in pressure and flows into the pipework system.

Learning Objective 1.1.2 - Describe the function of the volute and impeller in a centrifugal pump.

47

Pump Module 1.1.2 - The Volute and Impeller

Bernoulli’s Principle

This part explains Bernouli’s principle that defines the relationship between the pressure and speed of flowing liquids. Bernouli’s principle is key to understanding the function of the volute.

Impeller

This part explains the function of the impeller. The impeller is a rotating disc that has a series of outwardly curved vanes. The impeller spins at high speed inside the volute.

Volute

This part explains the function of the volute. The volute is a funnel shape that becomes larger from the suction flange to the discharge flange.

48

Pump Module 1.1.2 - Bernouli’s principle

Daniel Bernoulli

Daniel Bernoulli was an 18th Century Swiss mathematician and physicist.

Bernoulli discovered the principle that for fluids in an ideal state, pressure and speed are inversely proportional.

In simple terms, a slow moving liquid exerts more pressure than a fast moving liquid.

This animation shows liquid moving through a pipe that changes in area from large to small and back to large.

When liquid flows through the pipe from a large to small area it increases in speed and decreases in pressure.

When the liquid continues to flow from a small area to a large area its volume expands causing it to slow down.

As the liquid slows down its pressure increases.

A volute design utilizes this principle to slow down the speed of the liquid leaving the impeller

49

Pump Module 1.1.2 - The Volute

The volute is a casing that houses the impeller. It is made from a strong metal to withstand the high pressures and temperature variations of the pumped liquid.

The volute casing can be made from stainless steel, cast iron or bronze depending on the properties of the pumped liquid.

This animation reveals a section view of the volute. You can see how the funnel shape becomes larger from the suction to the discharge flange.

50



51


52



The volute casing can be made from stainless steel, cast iron or bronze depending on the properties of the liquid.

This animation reveals a section view of the volute. You can see how the funnel shape becomes larger from the suction to the discharge flange.

53

This animation shows the impeller rotating inside the volute casing. Please pay careful attention to the direction of rotation of the impeller and the shape of the impeller vanes.


54


This animation shows the flow of liquid expanding into the volute casing.

You can see the impeller rotating inside the volute. The function of the impeller is to transfer speed to the pumped liquid.



This animation shows a pressure gauge that indicates an increase in pressure at the discharge flange.


55

This section view of a single stage centrifugal pump shows the impeller positioned inside the volute.

You can also see all the major components of the centrifugal pump, drive coupling and electric motor.

This part will focus on the volute and impeller, you will explore the remaining components later in this module.

Pump Module 1.1.2 - The Impeller

56



57


This section view focuses on the impeller rotating inside the volute.

The animation zooms into the impeller so you can see its construction.

You can see the multiple vanes of the impeller and their curved shape.

The impeller is connected to a shaft and supported by a radial and thrust bearing.

In this type of centrifugal pump the impeller rotates at speeds from 1000 to 5000 revolutions per minute (RPM).

The impeller is also subject to pressures up to 8000 pound per square inch (PSI).

58


This impeller has six vanes that curve from the centre hub to the edge of the base disc.

A series of arrows are shown for illustration purposes to indicate how liquid accelerates across the vane.

The function of the impeller vanes is to increase the speed of the liquid as it is thrown from the eye of the impeller to its edge.

Check out the shape of the curved vanes in relation to the direction of rotation of the impeller.

This is a very important design feature of the impeller. The curved vane shape ensures that liquid is thrown across its curved surface.

An incorrectly assembled impeller will cause the vanes to scoop the liquid and the pump will not work.

59


You can see the flow of liquid entering the eye of the impeller in this animation.

Watch carefully as it accelerates across the vanes and is directed into the volute.

This is where the liquid expands into the larger area of the volute and reduces in speed.

The arrow indicates the direction of flow as the liquid leaves the volute and enters the discharge line.

A design characteristic of this single stage centrifugal pump is the way the fluid flow changes direction by 90 degrees from suction to discharge.

60

This animation shows a 360 degrees view of the centrifugal pump. You can see the flow of liquid entering the suction line, and changing direction by 90 degrees to the discharge line.


61

Pump Module 1.1.2 - The Impeller and Volute Functioning Together

Imagine if you were able to strip away the casings so that you can focus on watching the flow of liquid through the pump.

These two animations do exactly that.

Click on the top animation and you will see the shape of the liquid as it fills the suction line, impeller and volute.

Click on the bottom animation to follow the flow of liquid entering the eye of the impeller, spinning across the curved surface of the vanes and entering the volute.

This animation emphasizes the 90 degree change of direction of the pumped liquid.

62

This animation shows how the volute increases in diameter from the suction to the discharge flange. You can see how the pressure progressively increases as liquid flows to the discharge flange.


63


This animation shows a typical centrifugal pump assembly found in the oil and gas and petrochemical industries.

Th is configura t ion shows the arrangement of the suction and discharge pipework.

This unit includes wedge gate isolation valves and a non return valve on the discharge side of the pump.

64

In this design of centrifugal pump liquid is drawn into the suction line and enters the volute.

The impeller increases the speed of the liquid and transfers it to the discharge line.

You can see the direction of flow of the liquid changes by 90 degrees.

This direction change is a design feature of this type of single stage centrifugal pump.


66

Pump Module 1.1.2 - The Function of the Volute and Impeller - Summary

Summary

This part of the Mechanical Engineering Program Of Instruction (POI) examined the function of the volute and impeller and explored the following learning outcomes:

• Bernouli’s Principle

• The function of the volute to decrease the speed of the pumped liquid and increase its pressure.

• The function of the impeller to increase the speed of the pumped liquid and change its direction by 90 degrees.

This POI will develop your knowledge of the volute and the impeller to help you understand the concept and function of a centrifugal pump.

You can work through the Volute and Impeller Review Questions to test your understanding of this part of the POI.

67

Pump Module 1.1.2 - Volute and Impeller Review Questions

Question Review 1.1.2 The Volute and Impeller

Check Answer

Question 1 of 12Drag a label onto the image to identify the changing size of the volute diameter.

Small Diameter

Small Diameter

Medium Diameter

Medium Diameter

Large Diameter

Large Diameter

68

1.2 Describe the function of the major parts of a centrifugal pump.

Pump Module 1.2 - Describe the function of the major parts of a centrifugal pump

69

Pump Module 1.2 - Static parts and rotating parts

This is a single stage, horizontal centrifugal pump.

The design of the pump includes static parts and rotating parts.

Each part has a different function that makes the centrifugal pump work efficiently.

The Static Parts:

• Volute

• Seal Housing

• Shaft Seal (Soft Packing)

• Bearing Housing

The Rotating Parts:

• Impeller

• Shaft Seal (Mechanical Seal)

• Shaft

• Bearings

• Coupling

This part of the module shows you where each part is located in the centrifugal pump and describes their function.

70

Pump Module 1.2 - Static parts - the function of the volute

The volute is a static part of the centrifugal pump.





71

This animation shows how the volute increases in diameter from the suction to the discharge flange. You can see how the pressure progressively increases as liquid flows to the discharge flange.


72


73

Pump Module 1.2 - Static parts - the function of the seal housing

The seal housing is a static part of the centrifugal pump.

The seal housing connects directly to the volute casing and holds the shaft seal. The shaft seal can be a soft packing design or a mechanical seal design.

The function of the seal housing is to hold the shaft seal and stop pressurized pumped liquid escaping from the volute.

The seal housing includes a connector that links to the discharge port of the volte. This enables a pipeline to connect the volute to the seal housing to flush and lubricate the seal.

The seal housing also connects to the bearing housing and gives the pump structural strength.

74

Pump Module 1.2 - Static parts - the function of the seal housing

75

This close up section view of the seal housing shows soft packing compressed against the shaft.

Several rings of soft packing are inserted into the seal housing to ensure pressurized pumped liquid does not leak from the pump.

The seal flushing line cools and lubricated the soft packing.

76

Pump Module 1.2 - Static parts - the function of the bearing housing

The bearing housing is a static part of the centrifugal pump.

The bearing housing connects directly to the seal housing and locates and positions two ball bearings.

The bearing housing also holds a reservoir of lubricating oil inside an oil sump.

The oil level inside the oil sump is maintained by a constant level oiler that automatically refills the sump.

The bearing housing includes a sight glass that gives a visual indication of the oil level in the sump.

78

Pump Module 1.2 - Static parts - the function of the bearing housing

The bearing housing locates and positions two ball bearings. The ball bearings support the shaft as it rotates at high speed.

The ball bearings run at a high temperature and are cooled by lubricating oil.

The lubricating oil is held in an oil sump that is part of the bearing housing.

79

Pump Module 1.2 - Rotating parts - the function of the impeller

The impeller is a rotating part of the centrifugal pump.

The function of the impeller is to transfer speed to the pumped liquid.

Liquid is sucked into the eye of the impeller and thrown across the vanes to the edge.

These animations show the major parts and operation of the impeller.

80


This impeller has six vanes that curve from the centre hub to the edge of the base disc.

A series of arrows are shown for illustration purposes to indicate how liquid accelerates across the vane.


Check out the shape of the curved vanes and the direction of rotation of the impeller.

This is a very important design feature of the impeller. The curved vane shape ensures that liquid is thrown across its curved surface.

An incorrectly assembled impeller will cause the vanes to scoop the liquid and the pump will not work.

81



You can see the flow of liquid entering the eye of the impeller in this animation.

Watch carefully as it accelerates across the vanes and is directed into the volute.

The volute is a funnel shape that increases in diameter from the suction to the discharge flange,

This is where the pumped liquid expands into the larger area of the volute and reduces in speed.

When the pumped liquid reduces in speed it increases in pressure.

A design characteristic of this single stage centrifugal pump is the way the fluid flow changes direction by 90 degrees from suction to discharge.

82

Pump Module 1.2 - Rotating parts - the function of the mechanical seal

The function of the mechanical seal is to stop pressurized pumped liquid from the volute leaking out of the seal housing.

The mechanical seal is an assembly of static and rotating parts.

The main static sealing element is made from a highly polished and precisely manufactured nickel ring.

The main rotating sealing element is the carbon seat. This part also has a highly polished ring surface that mates with the static nickel sealing element.

A microscopically thin film of pumped liquid separates and lubricates the static and rotating sealing surfaces.

Watch these animations to gain an understanding of the parts of a mechanical seal.

83

Pump Module 1.2 - Rotating parts - the function of the mechanical seal

This animation shows the mechanical seal rotating with the pump shaft.

You can see the nickel seal element rotating against the static carbon seal element.

A seal flushing line feeds cooling liquid from the discharge port of the volute to the mechanical seal faces.

84

Pump Module 1.2 - Rotating parts - the function of the bearings

The function of the bearings of a centrifugal pump is to support the shaft assembly as it rotates at high speed.

This centrifugal pump is fitted with deep groove ball bearings to resist the radial forces of the rotating shaft assembly.

The radial ball bearings are positioned at the coupling end of the shaft to withstand the radial (rotating) forces generated through the connection to the coupling.

The thrust ball bearings are positioned at the impeller end of the shaft to withstand the axial ( forward and backward) forces generated through the high speed rotation of the impeller.

Some larger capacity and faster spinning centrifugal pumps have roller bearings fitted to the shaft to resist the greater forces.

85

When a centrifugal pump rotates at high speed it creates two types of forces.

The pressure of the pumped liquid creates forces that push along the center line of the rotating shaft assembly.

These forces are called axial thrust forces and must be restricted to a minimal amount of movement.

If axial movement exceeds the design limits of the pump important parts like the impeller or mechanical seal will come into contact with the casing and the pump will break down.

The high speed spinning shaft assembly also creates radial forces that act on the rotating parts.

Radial forces can stop the shaft assembly rotating smoothly inside the pump casing.

The function of this double row, deep groove ball bearing is to resist the axial thrust and radial forces generated by the fast spinning shaft assembly.

This animation shows how radial and axial thrust forces act on a double row, deep groove ball bearing.


86


This is a single row, deep groove ball bearing. This type of bearing can support low axial and radial loads.

This design of ball bearing is suitable for centrifugal pumps that rotate at high speed.

A single row, deep groove ball bearing can tolerate moderate levels of shaft misalignment.

87

Single Row - Deep Groove - Ball BearingSingle Row - Deep Groove - Ball Bearing

Part Number Part Description1 Outer Ring2 Caping Seal - Elastomer or Sheet Steel3 Inner Ring4 Ball Bearing5 Ball Bearing Gage6 Snap Ring Groove7 Outer Ring Raceway8 Ball Bearing Gage9 Inner Ring Raceway


88


This is a double row, deep groove ball bearing. This type of bearing can support heavy shaft assemblies and is usually fitted to pumps transferring slurry liquids.

This design of bearing has two rows of ball bearings and provides a greater radial load bearing capacity.

A double row, deep groove ball bearing can rotate at moderate speed and tolerate low levels of shaft misalignment.

89


Double Row - Deep Groove - Ball BearingDouble Row - Deep Groove - Ball Bearing

Part Number Part Description1 Outer Ring2 Caping Seal - Elastomer or Sheet Steel3 Inner Ring4 Double Row of Ball Bearings5 Ball Bearing Gage6 Double Outer Ring Raceway7 Double Row of Ball Bearings8 Double Inner Ring Raceway

90


This single row angular contact ball bearing is designed to resist axial thrust loads and radial loads.

Angular contact ball bearings are fitted to the shaft assembly of this multi stage centrifugal pump.

When the pump rotates the pressure pushes against the impellers and produces a load that tends to move the shaft assembly in an axial direction.

Angular contact ball bearings resist axial loads and ensure the shaft assembly and impellers run centrally inside the pump casing.

91

Single Row - Angular Contact - Ball BearingSingle Row - Angular Contact - Ball Bearing

Part Number Part Description1 Outer Ring2 Brass Cage3 Inner Ring4 Angular Contact Ball Bearing5 Brass Cage - Section View6 Outer Ring Raceway7 Inner Ring Raceway8 Brass Cage - Front View


92

Pump Module 1.2 - Rotating parts - the function of the coupling

The function of the coupling is transmit drive from the electric motor to the pump.

This is a gear coupling that has an external sleeve and internal hub.

The internal diameter of the sleeve has a series of gears that match with gears on the external diameter of the hub.

This design of coupling has a small amount of flexibility due to the mechanical alignment of the matching gear teeth.

93

Pump Module 1.2 - Rotating parts - the function of the coupling

This is a vertical submersible centrifugal pump.

This type of pump is used to transfer slurry liquids from a well to storage tanks.

This pump is fitted with a tyre coupling that has the capacity to absorb medium levels of misalignment.

Tyre couplings are described as flexible couplings because the rubber material can distort and still transmit drive from the motor to the pump.

94

Question Review 1.2 The function of the parts of a centrifugal pump.

Check Answer

Question 1 of 10Select the letter that completes this sentence.

The function of the volute is to ................... the pressure of the pumped liquid.

A. Increase

B. Decrease

C. Reduce

Pump Module 1.2 - Centrifugal Pump Parts Review

Centrifugal and Positive Displacement...

Documents

Transcript of Centrifugal and Positive Displacement...