Training Pump

8/10/2019 Training Pump

1/52

SINGLE STAGE CENTRIFUGAL PUMPS

IRI-SM-06-EMD

EQUIPMENT MAINTENANCE DESCRIPTION

INDUSTRIAL RESOURCES, INC.

A TRAINING SERVICES COMPANY

August 24, 2005

This document is the property of Industrial Resources, Inc. Copies and distribution of this document is prohibitedunless written authorization is granted by Industrial Resources, Inc.


2/52

PREFACE

This Training Equipment Maintenance Description (EMD) has been designed to assist you in

meeting the requirements of the Maintenance Training Program. It contains information about the

Single Stage Centrifugal Pumps. This includes function, quantity of parts, location of parts,

description of the physical construction of the part, and description of the operation of the part,

equipment preventive and corrective maintenance, and references.

You should review each chapter objective. In doing so you will be better prepared to learn the

required information. You should also inspect the equipment, identifying its components and

controls. Should you have additional question about the equipment, ask your supervisor.

A separate document, Single Stage Centrifugal Pumps Equipment Maintenance Procedure IRI-SM-

06-EMP, covers detailed maintenance of the Single Stage Centrifugal Pumps Equipment.


3/52

SINGLE STAGE CENTRIFUGAL PUMPS

IRI-SM-06-EMD

TRAINING EQUIPMENT MAINTENANCE DESCRIPTION

TABLE OF CONTENTS

1.0 Introduction......................................................................................................................... 4

1.1 Equipment Function............................................................................................................ 4

1.2 Equipment Description ....................................................................................................... 4

1.2.1 Equipment Data .................................................................................................................. 9

1.3 Equipment Connections and Interface ................................................................................ 9

2.0 Equipment Major Parts ..................................................................................................... 10

2.1 Pump Casings.................................................................................................................... 10

2.2 Seal Chamber/Stuffing Box .............................................................................................. 112.3 Volutes and Diffusers ....................................................................................................... 14

2.3 Impellers ........................................................................................................................... 16

2.4 Wear Rings........................................................................................................................ 18

2.5 Shaft Sleeves..................................................................................................................... 24

2.6 Couplings .......................................................................................................................... 24

3.0 Equipment Preventive and Corrective Maintenance......................................................... 27

3.1 Preventive Maintenance.................................................................................................... 27

3.2 Corrective Maintenance .................................................................................................... 27


4/52

List of Figures:

Figure 1 Single Stage Centrifugal Pump

Figure 2 Single Stage, End Suction Centrifugal Pump

Figure 3 Side Suction Pump

Figure 4 Down Suction Pump

Figure 5 End Suction Pump

Figure 6 Solid Pump Casing

Figure 7 Split Pump Casing

Figure 8 Stuffing Box Assembly

Figure 9 Seal Chamber Assembly

Figure 10 Double Volute Pump

Figure 11 Diffuser Pump

Figure 12 Closed, Double Suction ImpellerFigure 13 Closed, Single Suction Impeller

Figure 14 Open Impeller

Figure 15 Impeller Flow Types

Figure 16 Flat Style Wear Rings

Figure 17 L style Wear Rings

Figure 18 Labyrinth Style Wear Rings

Figure 19 Axial Forces on a Single Suction Impeller

Figure 20 Axial Forces on a Double Suction Impeller

Figure 21 Shaft Sleeve

References:

Goulds Centrifugal Pump Manual


5/52

1.0 Introduction

Chapter Objectives:

1. Describe the functions of Single Stage Centrifugal Pumps.

2. State, from memory, the functions of Single Stage Centrifugal Pump equipment.

3. Describe how Single Stage Centrifugal Pumps are operated and maintained.

4. List the normal Single Stage Centrifugal Pump operating parameters.

1.1 Equipment Function

The function of Single Stage Centrifugal Pumps is to move a liquid from one (1) point to another

using centrifugal force to increase the fluids pressure and maintain flow.

1.2 Equipment Description

The Cajun 2 Generating Facility is equipped with numerous Single Stage Centrifugal Pumps.Figure 1 is an example of a Single Stage, Double Suction, Centrifugal Pump.

Figure 1 Single Stage Centrifugal Pump

Figure 2 is an example of a Single Stage, Single End Suction Centrifugal Pump.


6/52

Figure 2 Single Stage, End Suction Centrifugal Pump

Centrifugal pumps move fluids by stirring them faster and faster in a circular motion and thenchanging the increased speed of the fluid into pressure. Depending on the design of the

particular pump, centrifugal pumps are capable of either very high or very low discharge

pressures and very high or very low volume discharges.

The pump shaft, driven by a motor or other prime mover, rotates, causing the impeller, which is

attached to it, to rotate also. The fluid being pumped enters through the suction eye at the center

of the impeller and fills the inside of the casing. The vanes of the impeller catch this fluid,

stirring it in the same direction as the rotation of the impeller and the shaft.

As the water gains speed (kinetic energy), it pushes outward against the walls of the pump

casing. This is due to centrifugal force - the same force that causes a stone on the end of a string

to pull outward on its string when swung in a fast, circular orbit. As the water moves outward, it

makes room for more water and at the same time creates a suction, which draws more water in at

the suction eye of the impeller. When the water is discharged at the tip of the impeller into the

volute, it is moving very fast, that is, it contains a large amount of kinetic energy.In the volute, which widens at the discharge end, the water must spread out to fill the chamber.

In the course of spreading out, the water slows down. When the water is forced to slow down,

the kinetic energy (speed or motion) does not just disappear; it is transformed into pressure. This

pressure carries the water out of the pump through the discharge piping.


7/52

Centrifugal Pump Classifications

Centrifugal pumps are classified according to certain design features. For example, pumps can

be referred to as vertical or horizontal, single-suction or double-suction, single stage, double-

stage, or multi-stage, volute or diffuser, and radial-flow, axial-flow, or mixed flow. The name of

the pump might also include formation about the impeller: whether it is closed, open, or semi-

open. The mechanical design of the casing provides the added classifications of axially split,

radially split, or occasionally solid. It is not unusual, then, to hear a pump referred to as a

vertical, double suction, single stage diffuser pump with closed impellers.

Vertical and horizontal refer to the position of the shaft during normal operation. The shaft is

vertical and the motor is positioned above the pump itself. This arrangement allows the pump to

be submerged in the fluid without causing water damage to the motor. Vertical pumps may be

used where floor space is limited.

Horizontal pumps have their motors beside them on the same horizontal level and their shaftsrun parallel to the ground. Horizontal centrifugal pumps are further classified as 1) end

suction, 2) side suction, 3) bottom suction, and 4) top suction. Vertically mounted centrifugal

pumps are almost always bottom suction pumps.

Figure 3 Side Suction Pump

When the suction nozzle is placed on the side of the pump with its centerline horizontal, the

pump is called a side suction pump ( Figure 3 ). When the suction points vertically downward,

the pump is classified a bottom suction pump ( Figure 4 ). The most common type of pump,

with its suction horizontal and its centerline coincidental with the shaft is an end suction pump

(Figure 5 ).


8/52

Figure 4 Down Suction Pump

Figure 5 End Suction Pump

Centrifugal Pump Safety

The following precautions should be observed prior to starting a centrifugal pump:

Ensure the pump is filled and vented, to prevent gas binding and cavitation due to air and

gas in the pump casing.

Cooling water and lubricating systems should be verified operable before starting the

pump. This check should include checking lubricating oil levels and flow, and cooling

water temperatures to the bearings. Introduce cooling water to pump bearings and

lubricating oil systems slowly.


9/52

Bearings should be near normal operating temperature when the pump is started.

The suction valve of a centrifugal pump must be verified open prior to pump start, to ensure an

adequate flowpath to the pump impeller. The suction valve must remain open while the pump is

running. The discharge valve should be closed when a centrifugal pump is started, to prevent

excessive starting torque and load on the motor. During pump start, observe pump motor current

to ensure it drops to the normal operating range after the starting surge.

The discharge valve should not be closed for an extended period unless minimum (recirculating)

flow is verified adequate. Some recirculating flow is necessary to prevent overheating the pump.

Centrifugal Pump Operations

Before operating a centrifugal pump, the driver should be tested for its direction of rotation. Thearrow on the pump casing indicates the proper direction for rotation.

A centrifugal pump should not be operated until it is filled with fluid. If the pump is run without

fluid, there is danger of damage to liquid lubricated internal parts. Several methods can be used

to ensure that all the air is vented from the pump. The process of filling the pump with liquid

and evacuating all gases is called priming. Adequate priming can normally be assured once a

solid stream of fluid issues from the vent valve. In some systems, automatic priming is

accomplished utilizing a priming pump controlled by a float switch. Priming the pump and

venting the casing during system startup will prevent gas binding. Once the pump is started, the

occurrence of gas binding would be indicated by low flow and low discharge pressure readings.

Additionally, the motor would be drawing minimum current.

The ball bearings should be supplied with the proper grade of lubricant and oil lubricated

bearings should be filled to the overflow level.

Cooling water should be introduced carefully to pump bearings and lubricating oil. Use only

sufficient water to keep the lubricant at a safe working temperature. Before starting the pump,

bearing temperatures should be near ambient temperature. Prior to pump start, the main concern

is that the bearings are too cold, due to cooling water being supplied with the pump off. If

bearing temperatures are low, cooling water should be isolated until pump bearings are at normal


10/52

operating temperatures. Final inspection of all parts should be made carefully before starting the

pump. It should be possible to rotate the shaft by hand. This starts the flow of oil to the bearing

surfaces.

The pump is started with the discharge valve closed, because the pump operates at only 35-50

percent of full load when the discharge valve is closed. Pumps started with the discharge valve

open require more starting torque. But, if the liquid on the upper side of the discharge check

valve is under sufficient head, the pump can be started with the discharge valve open.

When the pump is started, the normal electrical response is high starting amps [five (5) to six (6)

times normal operating current]. This rapidly drops off to a lower equilibrium value.

Additionally, motor current is affected by system (fluid) temperature. At system startup, more

current is required to circulate the cooler (denser) fluid. After system warm-up, lower motor

current is necessary to maintain the equivalent flow rate. Overheating will result if a pump is

operated against a closed valve (dead headed) for more than a few minutes.

The smallest amount of flow that will prevent a pump from overheating is the pumps minimum

flow rating/requirement.

1.2.1 Equipment Data N/A

1.3 Equipment Connections and Interface

Centrifugal Pumps can directly and indirectly interface with other equipment, devices and

systems throughout the facility.


11/52

2.0 Equipment Major Parts

Chapter Objectives:

1. Describe how the equipment parts perform their function:

2. Draw from memory a diagram of the equipment showing major parts

3. State from memory, the names and functions of the major parts

4. Describe the location of the major parts

The major parts of Single Stage Centrifugal Pumps are as follows:

1. Pump Casings

2. Volutes and Diffusers

3. Impellers

4. Wear Rings

5. Shaft Sleeves

2.1 Pump Casings

Casings may be either solid or split. Solid casing ( Figure 6 ) implies a design in which the

discharge waterways leading to the nozzle are all contained in one (1) casting, or fabricated

piece. It must have one (1) side open so that the impeller may be installed into the casing. As

the sidewalls surrounding the impeller are in reality part of the casing, a solid casing, strictly

speaking, cannot be used, and designs normally called solid casing are really radially split. Most

single stage end suction pumps are solid casing pumps.

A split casing pump is made of two (2) or more parts fastened together and commonly referred to

as a horizontally split case pumps ( Figure 7 ).


12/52

Figure 6 Solid Pump Casing

Figure 7 Split Pump Casing

2.2 Seal Chamber/Stuffing Box

Seal chamber and Stuffing box both refer to a chamber, either integral with or separate from the

pump case housing that forms the region between the shaft and casing where sealing media are

installed. When the sealing is achieved by means of a mechanical seal ( Figure 8 ), the chamber

is commonly referred to as a Seal Chamber. When the sealing is achieved by means of packing,

the chamber is referred to as a Stuffing Box ( Figure 9 ). Both the seal chamber and the stuffing

box have the primary function of protecting the pump against leakage at the point where the shaft


13/52

passes out through the pump pressure casing. When the pressure at the bottom of the chamber is

below atmospheric, it prevents air leakage into the pump. When the pressure is above

atmospheric, the chambers prevent liquid leakage out of the pump. The seal chambers and

stuffing boxes are also provided with cooling or heating arrangement for proper temperature

control.

Pump Shaft

Mechanical Seal Shaft Sleeve

Mechanical Seal

GlandSeal Chamber /

Stuffing Box

Figure 8 Seal Chamber Assembly


14/52

Junk Ring Packing

Packing Gland / Gland Follower

O Ring

Shaft Sleeve

Cooling/Sealing Water

Lantern Ring

Stuffing Box

Figure 9 Stuffing Box Assembly

Numerous types of mechanical seals are available for each type and/or pump use. Refer to the

seal manufacturers detailed installation instructions for each one (1).

Packed pumps require a certain amount of leakoff to ensure the packing is lubricated and does

NOT burn up. Some, but not all packed pumps are equipped with lantern rings as illustrated in

Figure 9 , as well as junk rings. Lantern rings are spaced between packing rings so that they

line up with a water supply or leakoff point in the stuffing box as indicated in Figure 9 . Junk

rings are in place to prevent the packing from being extruded (pushed) into the pump case

interior.

All packed pumps will have a packing gland or gland follower ( Figure 9 again ) and the yellow

rings of packing in Figure 9 indicate where most of the packing compression/sealing is taking

place. It is important to count the number of packing rings before and after the lantern ring when

repacking a pump so as to get the lantern ring back where it belongs in relation to the feed hole.


15/52

2.3 Volutes and Diffusers

Volute and diffuser describes the area in which a centrifugal pump converts the kinetic energy of

the fluid into pressure.

The volute pump derives its name from the spiral-shaped casing surrounding the impeller. This

casing section collects the liquid discharged by the impeller and converts velocity energy into

pressure energy. A centrifugal pump volute increases in size from its initial point until it

encompasses the full 360 degrees around the impeller and then flares out to the final discharge

opening. The wall dividing the initial section and the discharge nozzle portion of the casing is

called the tongue of the volute or the cut-water.

In a single stage volute pump that is operating at normal capacities the forces on the impeller are balanced, at reduced flows they are not. The amount of this force depends on pressures and

impeller size. This force can distort (bend) the shaft and cause rubbing of the impellers on the

casing. If the condition persists, the result is often a broken shaft. There are several ways

to solve this problem. One (1) is to use heavier shafts and bearings. Another way is to use a

double-volute ( Figure 10 ), or a diffuser ( Figure 11 ).

The double-volute design ( Figure 10 ) consists of two (2) volutes 180 degrees apart that join at a

common discharge. This design does not eliminate the imbalance, but being 180 degrees apart,

they tend to neutralize each other.


16/52

Double Volute Wall

Figure 10 Double Volute Pump

Impeller

Volute

Diffuser Vanes

Figure 11 Diffuser Pump

Diffusers ( Figure 11 ) perform the same function as volutes, converting kinetic energy into

pressure energy. It consists of a number of vanes set around the impeller. These act to further

divide the forces to lessen shaft bending. Diffusers are used mainly in high-pressure multistage

pump designs and in vertical pumps.


17/52

2.3 Impellers

The efficiency of a centrifugal pump depends upon the form of impeller used. Impeller design

depends on the application of the pump and service conditions. If the impeller of a centrifugal

pump is installed backwards or if the prime mover is rotating in reverse, pump capacity will be

reduced, and turbulence and vibration will result. Remember that impeller vanes always slap the

water. They do not dig in. A centrifugal pump will work regardless of impeller rotation, but at a

reduced capacity if the impeller is installed correctly.

Impellers are classified as 1) open, 2) semi-open, or 3) closed. Enclosed (closed) impellers are

considered to be the most efficient. Figure 12 shows the parts of a closed double suction

impeller while Figure 13 shows a single suction impeller. Open impellers ( Figure 14 ) are

used to handle large quantities of water at low heads, such as needed for circulating water for a

condenser.

Figure 12 Closed, Double Suction Impeller


18/52

PACKINGGLAND

IMPELLER

CASEOUT

CASEWEARRING

PUMPINLET

IN

ININ

IN

OUT

OUT

Figure 13 Closed, Single Suction Impeller Flow

Figure 14 Open Impeller

Impellers are further classified by the flow path of the fluid through the impeller. This path may

be 1) axially, 2) radially, or 3) mixed ( Figure 15 ). Axial impellers, sometimes called propellers,

are designed to pump large quantities of water at no lifts and low heads. Their use is mainly for

drainage and irrigation.


19/52

RADIAL VANE IMPELLERS

VANESVANES

HUBHUB

IMPELLER SHROUDS

AXIS OF ROTATION

IMPELLER SHROUDS

AXIS OF ROTATION VANESVANES

HUBHUB

VANES

MIXED FLOW IMPELLERS

IMPELLER HUBVANES

AXIS OF ROTATION

AXIAL FLOW IMPELLERS

Figure 15 Impeller Flow Types

Mixed flows impellers impart both an axial and a radial flow to the fluid. Their purpose is to

provide high flow rates at low heads, as with axial flow impellers. The radial (centrifugal) action

allows for higher suction lift.

2.4 Wear Rings

The joint between the impeller and the casing is subject to a high degree of wear. ''Wear rings

provide an easily renewable leakage joint between the impeller and the casing. An. impeller


20/52

casing joint without wear rings would have to be built up by welding or metal spraying to restore

their original clearances.

There are various types of wear ring designs. The type used for a particular unit will depend on:

a. Impeller speed

b. Pressure differences across the joint

c. The liquid being handled

The most common types of wear rings are:

a. The flat type

b. The L-type

c. The labyrinth type

Flat rings ( Figure 16 ) are the simplest. They provide a straight axial clearance between the

impeller and the casing. The L-type rings ( Figure 17 ) provide tight radial clearances. The axial

clearance is larger to slow down leaking fluid as it enters the suction stream. Some L-type wear

rings (as shown here) are designed to direct the fluid into the impeller eye. These are referred to

as nozzle rings. The labyrinth type ( Figure 18 ) wear rings function the same as labyrinth

seals do. They provide a long, unbroken path with high flow resistance to reduce the

flow.


21/52

PUMP CASE

CASEWEAR RING

IMPELLERWEAR RING

IMPELLER

Figure 16 Flat Style Wear Rings

IMPELLERWEAR RING

IMPELLER

CASEWEAR RING

PUMP CASE

Figure 17 L Style Wear Rings


22/52

PUMPCASE

CASE WEARRING

IMPELLER

WEAR RING

IMPELLER

Figure 18 Labyrinth Style Wear Rings

In small single-suction pumps the wear rings are usually pressed into the casing. Some may be

further locked on by setscrews. Casing rings on larger units are sometimes held in place with a

flange screwed to the casing. In axially split pumps, the casing rings are just set on a pin or

tongue that projects into the casing and is used to prevent these rings from rotating.

Impeller rings are often press fit or shrink fit onto the impellers. Setscrews are used with these

fits at times to provide added strength to the fit. Other designers prefer to screw the rings on to

the impellers. Again, sometimes setscrews are added.

Centrifugal pumps are unbalanced machines. The pressures inside the pump produce forces on

both the rotating and non-rotating parts. By their design, impellers impart an axial thrust toward

the suction side. This is due to the imbalance of forces between the suction and discharge sides

of the impeller. On lower pressure units the pumps thrust bearings are able to take this load. As

pressure differences across the impeller increase the loads on the bearings increase, and a means to

balance the forces ( Figure 19 ) must be used.


23/52

DISCHARGEPRESSURE

SUCTIONPRESSURES

INGLE

SUCTION

IMPELLER

Figure 19 Axial Forces on a Single-Suction Impeller


24/52

Another method of reducing the axial thrust on single-stage pumps is by means of a double-suction

impeller ( Figure 20 ). This impeller has two (2) suction eyes diametrically opposed and thus the

forces on the impeller theoretically cancel. In actuality, minor difference in flow rates and running

clearances at each impeller eye create some imbalance and thrust bearings are installed on these

units.

DOUBLE SUCTION IMPELLER

Figure 20 Axial Forces on a Double Suction Impeller


25/52

2.5 Shaft Sleeves

Shaft sleeves ( Figure 21 ) are used on pumps to protect the shaft from erosion and corrosion.

Shaft sleeves are commonly used as stuffing boxes leakage joints and bearings and, like wear

rings, provide a cheap and easy way to renew a shaft to its original dimensions.

Figure 21 Shaft Sleeve

Shaft sleeves used at specific locations are given names that reflect their purpose. For

example, a shaft sleeve is a multistage pump between two (2) impellers running through the

interstage bushing is called a distance sleeve or an interstage sleeve. Sleeves may be mounted

by:

a. A keyway and shaft nut

b. A threaded or screwed fitting

On some pumps a shaft sleeve with a threaded fitting may have a left hand thread. The threaddirection will depend on the rotation of the pump and which end of the shaft the sleeve is on. The

purpose for this is so that the frictional grip of the packing or bearing will tighten the shaft sleeve

not loosen it.

2.6 Couplings

Couplings can compensate for axial growth of the shaft and transmit torque to the impeller.

Shaft couplings can be broadly classified into two (2) groups: rigid and flexible. Rigid couplings

are used in applications where there is absolutely no possibility or room for any misalignment.

Flexible shaft couplings are more prone to selection, installation and maintenance errors.

Flexible shaft couplings can be divided into two (2) basic groups: elastomeric and non-

elastomeric.


26/52

Elastomeric couplings use either rubber or polymer elements to achieve flexibility. These

elements can either be in shear or in compression. Tire and rubber sleeve designs are elastomer

in shear couplings; jaw and pin and bushing designs are elastomer in compression couplings.

Non-elastomeric couplings use metallic elements to obtain flexibility. These can be one (1) of

two (2) types: lubricated or non-lubricated. Lubricated designs accommodate misalignment by

the sliding action of their components, hence the need for lubrication. The non-lubricated

designs accommodate misalignment through flexing. Gear, grid and chain couplings are

examples of non-elastomeric, lubricated couplings. Disc and diaphragm couplings are non-

elastomeric and non-lubricated.

Pump to driver alignment is critical to the operation of the equipment and misalignment is the

number one (1) cause of premature rotating equipment failure. The instructions/tolerancesallowed by the coupling manufactures more often times then not, way beyond the equipment

(pump and motor) manufactures recommendations for amount of misalignment.

The flexible coupling is designed to compensate for any equipment/system abnormalities such

as those found during startup or shutdown of rotating equipment. It is often the case where a

pump will be purposely aligned low to the driver (motor) in a cold state because we know the

pump is going to grow (expand) when it heats up, especially when pumping a heated liquid.

This is done so that the pump grows into alignment as it heats up rather than the alternative of

a perfect cold alignment that grows out of alignment as it heats up.

On any pumping equipment where the pump is driven by an electric motor, the motor is moved

to align to the pump for some obvious reasons. The most obvious is the rigid suction and

discharge piping. There are no such restrictions on the movement of the motor and it is therefore

the logical choice for movement.

Axial alignment is also critical especially on the larger installations where the motor is equipped

with plain Babbitt bearing with no provision for thrust containment or control. In these

situations the thrust of the coupled equipment (pump to motor) is controlled by the pumps thrust

bearing. It is imperative that on these installations, the motor is run for Mag-Center when the


27/52

coupling is NOT made up. This ensures that the motors Mag-Center and the pumps thrust are

not in a constant battle for the axial position of the rotating elements.


28/52

3.0 Equipment Preventive and Corrective Maintenance

3.1 Preventive Maintenance

Preventive maintenance for Single Stage Centrifugal Pumps consists of a number parameters.

Greasing or changing oil in the bearings (which will depend on the pump size and design),

vibration analysis and pump efficiency changes.

3.2 Corrective Maintenance

Corrective maintenance would be dependent on the current pump conditions and/or operating

abnormalities.


29/52

Industrial Resources, Inc. Single Stage Centrifugal PumpMechanical Maintenance IRI-SM-06-EMP

Page 1

SINGLE STAGE CENTRIFUGAL PUMP

IRI-SM-04EMP

TRAINING EQUIPMENT MAINTENANCE PROCEDURE



August 24, 2005



30/52


Page 2

PREFACE

This Training Equipment Maintenance Training Procedure (EMP) has been designed to assist you

in meeting the requirements of Module IRI-SM-04 of the Maintenance Section Training Program.

It contains information pertaining to maintenance of the Single Stage Centrifugal Pump. This

includes purpose, precautions, limits and setpoints, procedures and references for maintaining

equipment.

You should also inspect the equipment, identifying its components and controls. Should you have

additional question about the equipment maintenance, ask your supervisor.


31/52


Page 3


IRI-SM-06EMP

TRAINING EQUIPMENT MAINTENANCE PROCEDURETABLE OF CONTENTS

I. Purpose............................................................................................................................... 0

II. Precautions, Limitations, and Setpoints ......................................................................... 0

III. Procedure........................................................................................................................... 0

A. Operating Procedure ........................................................................................................... 0

B. Preventive Maintenance...................................................................................................... 1

C. Corrective Maintenance ...................................................................................................... 1


32/52

I. Purpose

This procedure provides information and guidance for the correct and safe use and

maintenance of the Single Stage Centrifugal Pump.

II. Precautions, Limitations, and Setpoints

A. Prior to performing any work on system pumps, Lock-Out and Tag-Out the

pump/motor to be worked on.

B. Ensure that the system involved is depressurized and/or drained/isolated prior to

removing a pump from a system line.

C. Proper personal protective gear should be worn at all times when working on a pump

in place.

D. Prior to starting a centrifugal pump, ensure that the pump case is filled and vented.

E. Ensure that the pumps cooling water (if so equipped) and lubrication system are in

place and operable.

F. Ensure that the pumps suction valve (if so equipped) is open prior to starting the

pump.

III. Procedure

The following procedures provide detailed instructions for conducting routine

operations, as well as preventive and corrective maintenance on Single Stage

Centrifugal Pumps.

A. Operating ProcedureThe following procedures provide detailed instructions for conducting routine

operations, as well as preventive and corrective maintenance on system centrifugal

pumps.


33/52


Page 1

__1. Check pump and motor lubrication levels (lube oil reservoir) if so equipped.

__2. Open the pumps suction valve if so equipped.

__3. Start the pump/motor by depressing its START/RUN pushbutton.

__4. Listen for any abnormal or excessive noise from the pump/motor and shut

the unit down if necessary.

__5. Check that the pumps discharge pressure is normal and all other operating

parameters are good.

__6. Before leaving the immediate area of the pump/motor check that there are

no obvious leaks coming from the pump or its associated piping.

B. Preventive Maintenance

The following steps are to be used by the equipment operator when performing preventive maintenance on Centrifugal Pumps.

__1. On those pumps/motors so equipped, grease the pump/motor bearings with

Grade 2 general-purpose grease.

__2. On those pumps/motors so equipped, check oil levels and add oil as

needed being sure to use the recommended grade.

C. Corrective MaintenanceFollow the equipment manufacturers instructions for the repair and/or

replacement of parts. The following generalized guidelines would apply to any

equipment (pump) installation.


34/52


Page 2

__1. Using the prescribe clearance procedure, ensure the pump is isolated from

the system by closing all suction, discharge, bypass and vent valves if soequipped.

__2. Using the prescribed clearance procedure, ensure the motor is isolated

from the Electrical System.

Horizontal Split Case Pump

The following procedure is for working a horizontally split case pump to remove

the rotating element.

__1. Disassemble the motor to pump coupling.

__2. Remove the horizontal bolting holding the top half of the cast to the

bottom half.

__3. Using a come-along or other lifting device, carefully lift the top half of thecase off and set aside.

__4. Save the horizontal joint gasket or make note of its size (thickness).

__5. Remove the upper half bearing housings if so equipped.

__6. Using a come-along or other lifting device, carefully lift the rotating

element from the case and place on v-blocks or have some other way of

preventing the element from rolling around during transport to the shop.


35/52


Page 3

__7. Remove the case wear rings from the impeller and slide them off the end

of the shaft.

__8. Depending on the reason for disassemble (operational problem); take as

found run out (dial indicator) readings of the element prior to further

disassembly ( Figure 1 ).

Impeller

Shaft Sleeve

Sleeve Nut

Pump Shaft

BearingBearing

Impeller Wear Rings

Figure 1 Pump Rotating Assembly

__9. Remove ball or roller bearings from shaft if so equipped. Do NOT discard

the old bearings until such time as new ones have been matched up.

__10. Remove the shaft sleeve nuts from each end of the shaft remembering that

one (1) will be a left hand thread and one (1) will be a right hand thread.

__11. Remove the shaft sleeves from each end of the shaft.


36/52


Page 4

__12. Remove the impeller from the shaft.

__13. Take as found run out readings of the bare shaft.

__14. Take and record sizes of bearing fits, shaft sleeve fits as well as sleeve

OD, impeller fit on shaft and bore of impeller as well as impeller wear

ring OD (90 degrees apart for roundness as well).

__15. Take and record case wear ring ID (90 degrees apart for roundness as

well) and compare to impeller wear ring OD for running clearance check.

__16. It is NOT normally necessary to replace both the impeller wear rings and

case wear rings at the same time. A judgment will need to be made based

on the condition of both, as to which one (1) will be replaced (if need be).

NOTE: Of the two (2), the impeller wear rings are the easiest to replace as

they typically require less machining than most types of case wear rings.The following procedure covers the replacement of impeller wear rings

Replace Impeller Wear Rings

The impeller wear rings can be replaced (machined) with the impeller mounted on

the pump shaft or an expandable precision arbor. In either instance the impeller

wear ring fit should be machined concentric with the bore of the impeller.

__1. Remove the grub screws from the impeller to impeller wear ring fit, if so

equipped. Some wear rings are staked in place in which case the stakes

will need to be ground or machined out.


37/52


Page 5

__2. Once the grub screws are removed, the impeller wear rings can be

removed by either machining them off or heating them until they expand

enough to be taken off by hand.

__3. At this point the impeller wear ring fit to impeller bore should be checked

for concentricity and roundness.

__4. New impeller wear rings are then machined (bored) for a shrink fit to the

impeller wear ring fit allowing .0002 to .0005 per inch of diameter for the

interference (shrink) fit. The OD of the impeller wear rings are left big for

final machining when installed on the impeller.

__5. Heat to expand the impeller wear rings and place them on the impeller.

__6. Install grub screws axially between the impeller and impeller wear ring fit

(Figure 2 ).


38/52


Page 6

Grub Screws

Impeller

Impeller Wear Ring

Figure 2 Axial Grub Screws

__7. Machine impeller wear ring OD for required running clearance to the case

wear rings.

Reassembly of Rotating Element

__1. Install the impeller on the pump shaft.

__2. Install the shaft sleeves.

__3. Install and tighten the shaft sleeves retaining nuts.

__4. At this point check the run out of the shaft to ensure that the impeller,

sleeve and sleeve nut axial faces are perpendicular to their bores.


39/52


Page 7

NOTE: Any debris between the axial faces or non-perpendicularity will

cause the pump shaft to bend, regardless of the shaft size and NOW is the

time to find it.

__5. Using a prescribed method, install the bearings on the shaft.

Pump Reassembly

We are assuming that the pump case has been prepared for reassembly with clean

flanges and a new gasket has been made to fit the case.

__1. Transport the rotating element with case wear rings installed to the pump

installation site and install the rotating element in the lower pump case

making sure to fit the case wear rings in their proper location.

__2. Install the upper half bearing housing if so equipped.

__3. Rotate the pump element by hand to ensure its freedom of movement.

__4. Install the pumps upper case half with a new gasket of the same thickness

as the old one (1).


__6. Install the horizontal bolting and using the correct tightening sequence,

tighten the bolts.



40/52


Page 8

__8. Check the alignment of the pump to the motor based on the manufactures

recommendations and move the motor if necessary to align.

__9. Make up the pump to motor coupling and rotate the pump and motor by

hand to ensure their freedom of movement.

__10. Witness the running of the pump and motor by operations to ensure there

are no problems with the pump.

Replacement of Bearings

Replacement of just the pump bearings involves an abbreviated version of the

complete work scope above.


41/52


IRI-SM-04JPM

TRAINING EQUIPMENT JOB PERFORMANCE MEASURE



August 24, 2005



42/52


Page 1

Maintenance Mechanic IRI-SM-06-JPM

Performance Measure: Single Stage Centrifugal Pump

Name: __________________________________

All Parts Satisfactorily Completed:

________________________________________ ____________________(Supervisors Signature) (Date)

Supervisors Comments: __________________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

References:

Training Module IRI-SM-04

Materials Needed: Pencil and Clipboard Equipment Maintenance Description Single Stage Centrifugal Pump IRI-SM-06-EMD Equipment Maintenance Procedure Single Stage Centrifugal Pump IRI-SM-06-EMP Associated Maintenance Checklist, Charts, Parts List, Technical Manuals

Safety/Environmental: Wear hard hats, safety glasses, safety toe shoe, and ear plugs as required. Discuss environmental hazards associated with performing maintenance of the equipment. Discuss any safety precaution that must be observed while performing the procedure.

Note: Always

observe all plant safety rules in accordance with Safety and Health Procedures and all

Federal, State and/or Local OSHA Standards.


43/52


Page 2

Part A: Locate Equipment

Locate and identify the following equipment and major components.

1. Single Stage Centrifugal Pump2. Rotating Element3. Coupling4. Bearings5. Driver (Motor)6. Suction Valve7. Discharge Valve

Satisfactorily Completed ____________________________

Part B: Controls/Breakers

Locate and identify the following isolation devices.

1. Control Breaker

Satisfactorily Completed _________________________


44/52


Page 3

Part C: Preparation for Maintenance

This is to be performed under direction of the Supervisor.Demonstrate the following preparation for use of Single Stage Centrifugal Pumps including:

1. Prior to performing any work on system pumps, Lock-Out and Tag-Out the pump/motor to be worked on.

2. Ensure that the system involved is depressurized and/or drained/isolated prior to removing a pump from a system line.

3. Proper personal protective gear should be worn at all times when working on a pump in place.4. Prior to starting a centrifugal pump, ensure that the pump case is filled and vented.5. Ensure that the pumps cooling water (if so equipped) and lubrication system are in place and

operable.

6. Ensure that the pumps suction valve (if so equipped) is open prior to starting the pump.

Satisfactorily Completed __________________________

Part D: Operating Procedure

This is to be performed under direction of the Supervisor.Demonstrate the following operational steps for the safe and efficient operation of Single Stage

Centrifugal Pumps.

Operating Procedure

1. Check pump and motor lubrication levels (lube oil reservoir) if so equipped.2. Open the pumps suction valve if so equipped.3. Start the pump/motor by depressing its START/RUN pushbutton.4. Listen for any abnormal or excessive noise from the pump/motor and shut the unit down if

necessary.5. Check that the pumps discharge pressure is normal and all other operating parameters are

good.6. Before leaving the immediate area of the pump/motor check that there are no obvious leaks

coming from the pump or its associated piping.



45/52


Page 4

Part E: Preventive Maintenance

This is to be performed under direction of the Supervisor.Demonstrate the steps on the Single Stage Centrifugal Pump required to perform the following preventive maintenance tasks.

Lubrication

1. On those pumps/motors so equipped, grease the pump/motor bearings with Grade 2 general- purpose grease.

2. On those pumps/motors so equipped, check oil levels and add oil as needed being sure to usethe recommended grade.


Part F: Corrective Maintenance

This is to be performed under direction of the Supervisor.Demonstrate the steps on the Single Stage Centrifugal Pump required to perform the followingcorrective maintenance.

1. Using the prescribe clearance procedure, ensure the pump is isolated from the system byclosing all suction, discharge, bypass and vent valves if so equipped.

2. Using the prescribe clearance procedure, ensure the motor is isolated from the electricalsystem.

Disassemble Split Case Pump

1. Disassemble the motor to pump coupling.2. Remove the horizontal bolting holding the top half of the cast to the bottom half.

3. Using a come-along or other lifting device, carefully lift the top half of the case off and setaside.4. Save the horizontal joint gasket or make note of its size (thickness).5. Remove the upper half bearing housings if so equipped.

(Continued on next page)


46/52


Page 5

Part F: Corrective Maintenance (Continued)

6. Using a come-along or other lifting device, carefully lift the rotating element from the caseand place on v-blocks or have some other way of preventing the element from rollingaround during transport to the shop.

7. Remove the case wear rings from the impeller and slide them off the end of the shaft.8. Depending on the reason for disassemble (operational problem); take as found run out

(dial indicator) readings of the element prior to further disassembly.9. Remove ball or roller bearings from shaft if so equipped. Do NOT discard the old bearings

until such time as new ones have been matched up.10. Remove the shaft sleeve nuts from each end of the shaft remembering that one will be a left

hand thread and one will be a right hand thread.11. Remove the shaft sleeves from each end of the shaft.

12. Remove the impeller from the shaft.13. Take as found run out readings of the bare shaft.14. Take and record sizes of bearing fits, shaft sleeve fits as well as sleeve OD, impeller fit on

shaft and bore of impeller as well as impeller wear ring OD (90 degrees apart for roundnessas well).

15. Take and record case wear ring ID (90 degrees apart for roundness as well) and compare toimpeller wear ring OD for running clearance check.

16. It is NOT normally necessary to replace both the impeller wear rings and case wear rings atthe same time. A judgment will need to be made based on the condition of both, as to whichone will be replaced (if need be).

Replace Impeller Wear Rings1. Remove the grub screws from the impeller to impeller wear ring fit, if so equipped. Some

wear rings are staked in place in which case the stakes will need to be ground or machinedout.

2. Once the grub screws are removed, the impeller wear rings can be removed by eithermachining them off or heating them until they expand enough to be taken off by hand.

3. At this point the impeller wear ring fit to impeller bore should be checked for concentricityand roundness.

4. New impeller wear rings are then machined (bored) for a shrink fit to the impeller wear ringfit allowing .0002 to .0005 per inch of diameter for the interference (shrink) fit. The OD ofthe impeller wear rings are left big for final machining when installed on the impeller.

5. Heat to expand the impeller wear rings and place them on the impeller.6. Install grub screws axially between the impeller and impeller wear ring fit.7. Machine impeller wear ring OD for required running clearance to the case wear rings.

(Continued on next page)


47/52


Page 6

Part F: Corrective Maintenance (Continued)

Reassembly of Rotating Element1. Install the impeller on the pump shaft.2. Install the shaft sleeves.3. Install and tighten the shaft sleeves retaining nuts.4. At this point check the run out of the shaft to ensure that the impeller, sleeve and sleeve nut

axial faces are perpendicular to the their bores.5. Using a prescribed method, install the bearings on the shaft.

Pump Reassembly

1. Transport the rotating element, with case wear rings installed, to the pump installation site

and install the rotating element in the lower pump case making sure to fit the case wearrings in their proper location.2. Install the upper half bearing housing if so equipped.3. Rotate the pump element by hand to ensure its freedom of movement.4. Install the pumps upper case half with a new gasket of the same thickness as the old one.5. Rotate the pump element by hand to ensure its freedom of movement.6. Install the horizontal bolting and using the correct tightening sequence, tighten the bolts.7. Rotate the pump element by hand to ensure its freedom of movement.8. Check the alignment of the pump to the motor based on the manufactures recommendations

and move the motor if necessary to align.9. Make up the pump to motor coupling and rotate the pump and motor by hand to ensure their

freedom of movement.10. Witness the running of the pump and motor by operations to ensure there are no problemswith the pump.



48/52


Page 7

Part G: Personnel and Equipment Safety

Performed all aspects of the JPM using safe operating practices and following plant safety andenvironmental procedures.



49/52


IRI-SM-04Q

TRAINING EQUIPMENT JOB PERFORMANCE MEASURE

TEST QUESTIONS



August 24, 2005



50/52

1. (IRI-SM-06-QB) ________ impellers are the most efficient design.

A. Mixed flowB. OpenC. ClosedD. Semi-closed

2. (IRI-SM-06-QB) Prior to starting a centrifugal pump it should be checked to ensure that the ____________.

A. packing is tight enoughB. case is filled with fluidC. packing is not too tightD. pump base is bolted down

3. (IRI-SM-06-QB) The rings of packing closest to _____________ see the most compression or

do most of the sealing.A. the gland followerB. lantern ringC. junk ringD. impeller

4. (IRI-SM-06-QB) Axial thrust forces on a single suction impeller are __________ those on adouble suction impeller.A. less thanB. greater thanC. equal toD. not of any consequence

5. (IRI-SM-06-QB) The type of wear ring used on a pump so equipped will depend on thespeed, pressure differences (suction and discharge) and _______________.A. mounting of the pumpB. process temperatureC. location of the pumpD. the type of liquid being pumped

6. (IRI-SM-06-QB) Impellers are further classified by the direction of flow through them beingeither radial, _________ or axial.A. propellerB. mixedC. staticD. conventional


51/52


Page 1

7. (IRI-SM-06-QB) Wear rings are used on pump impellers and cases to allow for __________.A. easy reestablishment of running clearancesB. misalignment of rotating elements

C. the use of dissimilar metalsD. pump joint leakage

8. (IRI-SM-06-QB) Shaft sleeves are used on pumps to ___________________.A. keep the pump shaft straight when runningB. seal the packing housingC. protect the pump shaftD. hold the bearings in place

9. (IRI-SM-06-QB) The wear rings on a centrifugal pump impeller are attached/installed with ashrink fir and ______________.A. radial grub screwsB. axial grub screwsC. permatex bondD. silver solder

10. (IRI-SM-06-QB) The OD of the impeller wear ring needs to be machined ___________.

A. concentric to the wear ring IDB. concentric to the impeller boreC. perpendicular to the impeller boreD. parallel to the impeller bore

11. (IRI-SM-06-QB) The different types of wear rings are flat, L shaped and _________________.A. staggeredB. labyrinthC. convolutedD. split

12. (IRI-SM-06-QB) Junk rings are in place __________.A. to allow for the use of identical pump shafts on different pumpsB. as spacersC. to make changing the packing easierD. to prevent the packing from being extruded (pushed) into the pump case interior


52/52


13. (IRI-SM-06-QB) The area where the packing is located on a packed pump is referred to as

___________.A. the stuffing boxB. the seal chamberC. the packing chamberD. the seal box

14. (IRI-SM-06-QB) There are several ways to solve a bending shaft problem, one (1) would be to ___________.

A. realign the pump

B. replace the pumpC. use a double volute pump caseD. redo the pump base plate

15. (IRI-SM-06-QB) The most common type of single stage centrifugal pump is ________________.

A. bottom suction pumpB. an end suction pumpC. side suction pumpD. top suction pump

Documents

Training Pump