KSB WK, WK 40, WK 100, WK 50, WK 65 Series Manual

Contents

WK

Point Description Page
No. No.

0 Introduction 1

1 Pump construction 1

1.1 Casing 1

1.2 Rotor 1

1.3 Bearing arrangement 2

1.4 Lubrication 3

1.4.1 Oil lubrication 3

1.4.2 Grease lubrication 4

1.5 Shaft seal 4

1.5.1 Stuffing boxes 4

1.5.1.1 Cooling liquid for stuffing boxes 5

1.5.1.2 Packing the stuffing boxes 5

1.5.1.3 Packing material 7

1.5.2 Mechanical seals 7

1.6 Coupling 7

2 Mode of operation of pump 7

3 Drive 8

4 Transport 8

5 Painting 8

6 Condition of equipment as supplied 8

7 Accessories 9

8 Installing the pumping set 9

8.1 Description of site prior to
commencement of erection 9

8.2 Installation and preliminary levelling up 9

8.3 Aligning the coupling 9

8.4 Grouting in the baseplate 10

8.5 Final alignment 10

9 Piping 11

9.1 Suction lift line and positive
Suction head line 11

9.1.1 Strainers in suction head line/suction lift line 11

9.2 Isolating valves 12

9.3 Non-return valves 12

9.3.1 Automatic recirculation valve 12

9.4 Final coupling check 13

9.5 Measuring instruments 13

10 Commissioning 13

10.1 Preliminary remarks regarding
commissioning 13

10.2 Start-up 13

10.3 Operation and supervision of pump 14

Point Description Page
No. No.

10.4 Shutting the pump down 14

10.5 Preserving the pump 15

10.6 Sending the pump back to our Works 15

11 Dismantling the pump 15

11.1 Preparations prior to dismantling 15

11.2 Dismantling the bearing 15

11.2.1 Dismantling the drive end bearing 15

11.2.2 Dismantling the end side bearing 16

11.2.2.1 Standard bearing construction 16

11.2.2.2 Heavy duty bearing construction 17

11.3 Removing the shaft seal 17

11.3.1 Soft-packed stuffing box construction 17

11.4 Dismantling the pump body 17

11.5 Inspection of individual pump components 19

11.6 Dynamic balancing of pump rotor 20

12 Assembly of pump 20

12.1 Preparations prior reassembly 20

12.2 Assembling the pump body 20

12.3 Assembly of shaft seal 22

12.3.1 Pump construction with soft-packed
stuffing box 22

12.4 Assembly of bearings 23

12.4.1 Assembly of end side bearing 23

12.4.2 Assembly of drive end bearing 23

13 Operating troubles, causes and remedies 25

13.1 Operating troubles 25

13.2 Causes for damage 25

13.3 Suggested remedies 26

14 Spare parts 27

15 Check list 28

15.1 Pre-requisites for initial commissioning 28

15.2 Initial start-up with cold water 28

15.3 Priming the boiler 28

15.4 Initial operation with hot fluid 28

15.5 Supervision of operations & maintenance 28

16 Sectional drawings and list of

components 29

Balancing liquid piping 31

WK

water compartment, which is sealed off against atmosphere
by the stuffing box housing cover (165) with flat gasket (400.3)
and O-ring (412.4) (See Fig. 2)

7A/7E

Fig. 1

0. Introduction

WK pumps are High Pressure Horizontal Centrifugal Pumps.
In accordance with the latest state of the art of pump design
and construction, our pumps combine favourable hydraulic
characteristics with a long service life, reliability of operation
and simple maintenance and operation.

A pre-requisite for trouble-free operation of the pumps is the
careful observance of the recommendations contained in this
operating instruction manual. It should therefore, always be at
the disposal of the personnel entrusted with the erection,
maintenance and operation of the pump.

It goes without saying that the pumps should only be operated
under the duty conditions specified (see data sheet). The terms
of our Guarantee naturally apply within this range of conditions.
Our Guarantee will become invalid if the pumps are dismantled,
either completely or partially, without our prior consent. The
first assembly and dismantling of the pump should be carried
out by skilled fitters and erectors, and this also applies to the
initial start-up (commissioning) of the pumping set.

400.3

350

165

452

412.3 412.4 461.1

400.3

451

524.2
(524.1)

Fig. 2 Stuffing box housing with cooling compartment cover

Depending on the number of stages and on the temperature
of the product pumped, the pump feet are integrally cast onto
the suction and discharge casings (106 and 107) either at the
bottom, or at shaft centerline height. The suction nozzle can
be arranged to point horizontally to the left or right hand side,
or vertically upwards, if the pump feet are arranged at the
bottom of the pump; if they are arranged at shaft centerling
height, the suction nozzle can only be arranged to point
vertically upwards the discharge nozzle points radially upwards
on both types of pump feet arrangement.

In order to achieve a favourable NPSH required, the suction
nozzles on all sizes of pumps are made one nominal size larger
than the discharge nozzles. The flange construction is specified
in the data sheet.

1.2 Rotor

All the rotating components assembled on the shaft make up
the complete pump rotor (See Fig. 3 and 4)

1. Pump Construction

(For item numbers, see under section 16, Sectional drawings.)

1.1 Casing

WK high pressure centrifugal pumps are single or multistage
centrifugal pumps with a radially split casing. This consists of
the suction and discharge casing (106 and 107) together with
a number of stage casings (108). If the extraction of a given
quantity of the liquid pumped at one of more intermediate
pressures is required, the corresponding stage casings can
be provided with extraction (Bleed off) nozzles. The individual
casing components are sealed off against one another by flat
gaskets (400.2) or by ‘O’ rings (412) and clamped together by
connection rods (905). The diffusers (171.1 and 171.2) are
arranged in the stage casings and in the discharge casing
respectively (108 and 107 respectively). They are centered in
the casings at their outer periphery and secured against
twisting.

The stuffing box housings (451) and bearing housing (350)
are flanged onto the suction and discharge casing respectively
(106 and 107) and attached by studs (902.1). The stuffing box
housings (451) are sealed off from the suction and discharge
casings respectively (106 and 107) by a flat gasket (400.3).
On pumps fitted with special hot water stuffing boxes or with
mechanical seals, the shaft seal is surrounded by a cooling

The shaft (210) transmits the torque generated by the drive
onto the impellers. The impellers (230) are mounted is
sequence on shaft (210), and they all point in the same
direction. They are secured against twisting by keys.

The narrow clearance gap between impeller neck and casing
wearing ring (502) at the suction and discharge end of each
impeller prevents the equalization of presure between one
stage and the next.

The shaft (210) is protected inside the pump against attack by
the fluid pumped by means of spacer sleeve (525.1/2) and
distance bushes stage (521). The distance bushes/stage also
serve to locate the impellers axially on the shaft. The shaft
(210) is protected by the shaft protection sleeves (524.1/.2) in
the region of the shaft seal. These protection sleeves are
screwed onto shaft (210) by means of screw threads with
opposed hand to the direction of rotation of the shaft.

Fig. 3 Assembled rotor

1

WK

5412 and standard bearing bracket (No adaptor sleeve
provided on pump size 150).

End side : 1 deep groove ball bearing in accordance with DIN
625 and standard bearing housing (see Figs. 7 and 8).

Heavy Duty Bearing Construction :

Drive end : Same as atandard bearing construction. End
side : 2 matched angular contact ball bearings in accordance
with DIN 628; X arrangement and heavy duty bearing bracket
(see Fig. 9).

Fig. 4 Dismantled rotor

In order to balance the axial thrust, throttling passages are
arranged at the impeller necks at the suction and discharge
end of each impeller, and additional balancing holes are
provided in the impeller necks at the discharge end
(See Fig. 5).

A fixed bearing absorbs the residual axial thrust generated
and also locates the rotor in the axial position; in the standard
bearing construction, this bearing consists of a deep groove
ball bearing (321) and in the pump construction with heavy
duty bearing bracket, it consists of two angular contact ball
bearings (320).

Fig. 5 Rotor

1.3 Bearing Arrangement

WK pumps are fitted with different types of beaings and bearing
housing, depending on the differential head (generated
pressure) of the pump. In the case of low differential heads,
the standard bearing construction is provided. In the case of
higher total heads, the heavy duty bearing construction is
provided to absorb the increased residual thrust.

The pump manufacturer decides which type of bearing
arrangement shall be provided.

361 920.4 321 350 350 731.2 322 400.4 901.2

400.4

903.4
(13B)

507

507 52-1 360 210

Fig. 7 Bearing construction, size 40 to 125

400.4 920.4 350 525.4

903.12

361 543 321 932 507 932 322 543

507 525.4 350 360

Fig. 8 Bearing construction, size 150

Drive end

Fig. 6 Individual bearing components (drive end)

Part 1 = Outer race with cage and rollers
Part 2 = Adaptor Sleeve
Part 3 = Inner bearing race
Part 4 = Locking Washer
Part 5 = Withdrawal Nut

Standard Bearing Construction :

Drive end : 1 Cylindrical roller bearing in accordance with DIN
5412 (see Fig. 6) with adaptor sleeve in accordance with DIN

901.3 361 913 350.2 412.7 507

903.5
(

)

13B

412.7 644 644 360.2

543400.5

525.8160

901.4

720.3
(8B)

210

932508320320923

525.5

902.3

Fig. 9 Bearing construction with heavy duty bearing
bracket size 150.

2

WK

Standard Construction

Pump size 40 50 65 80 100 125 150

Drive end :

cylindrical roller bearing NU 206 K NU 207 K NU 207 K NU 208 K NU 208 K NU 210 K NU 410
designation in accordance C 3 C 3 C 3 C 3 C 3 C 3 C 3
with DIN 5412

Adaptor sleeve in
accordance with DIN 5412

Non Drive end :

Deep groove ball bearing
designation in accordance 6403/C 3 6404/C 3 6404/C 3 6405/C 3 6405/C 3 6405/C 3 6410/C 3
with DIN 625

Oil fill in litres 0.16 0.18 0.18 0.25 0.25 0.28 0.45

Heavy Duty Bearing Bracket

Pump size 40 50 65 80 100 125 150

Drive end :

cylindrical roller bearing NU 206 K NU 207 K NU 207 K NU 208 K NU 208 K NU 210 K NU 410
designation in accordance C 3 C 3 C 3 C 3 C 3 C 3 C 3
with DIN 5412

Adaptor sleeve in
accordance with DIN 5415

Non Drive end :

Angular contact ball bearing
Din 628, 7305 BG 7306 BG 7306 BG 7307 BG 7307 BG 7309 BG 7310 BG
matched pair, X arrangement
Manufacturer SKF

FAG

Oil fill in litres 0.65 0.70 0.70 0.90 0.90 1.2 1.2

H 206 H 207 H 207 H 208 H 208 H 210 ---

H 206 H 207 H 207 H 208 H 208 H 210 ---

7305 B. UA 7306 B. UA 7306 B. UA 7307 B. UA 7307 B. UA 7309 B. UA 7310 B. UA

Drive at both Ends

Pump size 40 50 65 80 100 125 150

Suction side :

cylindrical roller bearing NU 206 K NU 207 K NU 207 K NU 208 K NU 208 K NU 210 K NU 410
designation in accordance C 3 C 3 C 3 C 3 C 3 C 3 C 3
with DIN 5412

Adaptor sleeve in
accordance with DIN 5412

Discharge side :

Deep groove ball bearing
designation in accordance 6305/C 3 6306/C 3 6306/C 3 6307/C 3 6307/C 3 6308/C 3 6410/C 3
with DIN 625

Oil fill in litres 0.16 0.18 0.18 0.25 0.25 0.28 0.45

Fig. 10 Bearing end oil requirement table

In case of the pump construction with drive at both ends, the
bearing arrangement at the suction end corresponds to the
standard construction. At the discharge end, deep groove ball
bearings in accordance with DIN 625 are fitted, but they are of
bearing series 63.

See Fig. 10 ‘‘Bearing and oil requirement table’’ for precise
bearing designation and size for the individual pump sizes.
Splash ring (507) on shaft (210) prevent the penetration of
any leakage liquid from the stuffing box into the bearing
housing.

H 206 H 207 H 207 H 208 H 208 H 210 ---

1.4 Lubrication

1.4.1 Oil Lubrication

Standard construction WK pumps are provided with oil splash
lubrication. The antifriction bearings are slightly submerged in
the oil sump, ensuring perfectly satisfactory lubrication at all
times. The max. oil level is automatically attained during topping
up when oil starts pouring out of the over-flow holes in the
bearing covers (360/361).

On request, we can fit constant level oilers (638), which will
necessitate the sealing of the shaft against the bearing bracket
by means of felt rings (422.1) (See Fig. 11 to 13).

3

WK

Oil Quality : Machinery oil possessing good air release

properties and corrosion prevention characteristics; kinematic
viscosity 36 cSt approx. = 4.80E at 500C; flash point 1500C
minimum; pour point lower than -200C.

Lubrication times : First oil change after the first 500 hours of
operation, subsequent oil changes after every 3000 hours of
operation approx., but at least once a year.

Overflow hole

Oil sump

Fig. 11 Oil splash lubrication

422.4

500.4

500.1 913 422.1

X

Portable (mobile) pumps, and pumps installed on board ship
have grease-lubricated bearings (See Fig. 14). Use a good
quality lithium soap ball and roller bearing grease, free of resin
and acid, and possessing rust preventive properties. The
grease should have a penetration number situated between 2
and 3, corresponding to a worked penetration situated between
2220 and 295 mm/10. Its drop point should be not less than

0

C.

175

731.2 636

Fig. 14 Grease lubricated bearing construction

The bearing temperature may be allowed to rise up to 400C
above room temperature, but should not exceed 800C. The
grease fill will last for 15000 hours of operation i.e., for 2 years
approx. If the operating conditions are arduous, the bearings
should be serviced once a year. A grease fill amounts to 10-20
grammes of grease, depending on the pump size. The pump
bearings are packed with grease at our Works before despatch.

End side
(Heavy duty bring bracket)

Drive end

Fig. 12 Construction with constant level oiler and sealing of
the bearing housing.

638

Fig. 13 Constant level oiler viewed from X

Topping up of the oil fill at least once a month.

The bearing temperature may be allowed to rise up to 40

0

above room temperature, but should not exceed 800C.

1.4.2 Grease Lubrication

(Cannot be provided on heavy duty bearing construction
pumps).

1.5 Shaft Seal

The shaft is sealed at its exits through the casings by softpacked
stuffing boxes or by mechanical seals. If the pump is fitted with
special stuffing boxes, mechanical seals can be fitted in lieu of
soft packing (or vice versa) at any time during the service life
of the pump, with a minimum of machining of the cooling
compartment covers. On the other hand, the fitting of
mechanical seals to pumps equipped with standard or hot water
type soft-packed stuffing boxes necesitates the fitting of new
pump components. Particulars can be obtained from the pump
manufacturer.

1.5.1 Stuffing Boxes

Soft-packed stuffing boxes reduce the flow of leakage liquid at
the clearance gap between casing and shaft protection sleeve
when the pressure inside the pump is higher than atmospheric.
Conversely, on pumps which operate on suction lift, the soft­packed stuffing box prevents the ingress of air into the pump.
Sealing is effected by means of soft packing (461.1) arranged
in a number of rings in the annular space between the stuffing
box housing (451) and the shaft protection sleeve (524.1/2)
and lightly compressed by the stuffing box gland (452).

Caution : On pumps which have a high discharge pressure,
the stuffing box at the discharge end is relieved of pressure,
via a balance liquid line, down to the suction pressure, provided
that the differential pressure across the pump exceeds 20 bar.
This ensures that the stuffing boxes at the suction and discharge
ends of the pump have the same admission pressure. This
arrangement applies to pump sizes 40 to 65 if the discharge

C

pressure exceeds 20 bar and to pump sizes 80 to 150 if the
discharge pressure exceeds 15 bar.

Single stage pumps require no special pressure relief even at
high discharge pressures. The pressure is relieved via the
balance holes in the impeller.

4

WK

Soft-packed stuffing box, ‘‘Standard’’ (N) construction.

Standard construction with 4 packing rings (461.1) used for
temperatures of the fluid pumped up to 1050C. The stuffing
box compartment cannot be cooled.

400.3

350

452

412.3

461.1

451

524.2
(524.1)

Fig. 15 ‘‘Standard’’ (N) construction stuffing box

7A/7E

400.3

350

165

452

412.3 412.4 461.1

400.3

451

524.2
(524.1)

Fig. 16 ‘‘Hot Water’’ (HW) construction stuffing box

Soft-packed stuffing box, ‘‘Hot Water’’ (HW) construction.
Construction with 4 packing rings (461.1) and cooling of the
stuffing box compartment. Used for temperatures of the fluid
pumped in excess of 105

0

C up to 2300C max.

Special stuffing box, ‘‘Extra-deep’’ (V) construction.
Construction with 7 packing rings (461.1) and cooling of the
stuffing box compartment, used mainly in process industry
applications.

7A/7E

400.3

451

524.2
(524.1)

165

452

412.3

400.3

350

412.4 461.1

Fig. 17 Special soft packed stuffing box ‘‘Extra deep’’ (V)

Special stuffing box, ‘‘VSM’’ Constructed
VSM is the abbreviation (in German) of ‘‘Extra deep with lantern
ring at the centre’’.

Construction with 5 packing rings (461.1) and one seal case
ring (458) arranged at the centre of the packing compartment;
used mainly for operation under vacuum or suction lift, and
where malodorous fluids are pumped. For operation under
vacuum, the lantern ring (458) is fed with a sealing liquid, and
it prevents the ingress of air into the pump.

10A/10E

400.3

350

165

452

412.3 412.4 461.1

458

400.3

451

524.2
(524.1)

Fluids pumped :
Operation under vacuum
or pumping of malodorous
fluids (ammonia and
solvents).

Sealing liquid consumption
1 to 3 litres/hours approx.

Fig. 18 Special stuffing box VSM

Special stuffing box, ‘‘VSH’’ constructed.
VSH is the abbreviation (in German) for ‘‘Extra deep with seal
cage ring at the bottom of the box’’. The construction with 5
packing rings (461.1) and a seal cage ring (458) arranged at
the bottom of the packing compartment is used where fluids
containing abrasive particles are pumped. The flushing liquid,
which should be fed through the cage ring (458) at a pressure
of at least 1 to 4 bar (max.) above the suction pressure,
penetrates inside the pump and protects the stuffing box
packing (461.1) against abrasive substances.

11E

458

400.3

451

524.2
(524.1)

Fluids :

Products containing abrasive
particles, which must be kept
away from the stuffing box
packing, so as not to erode
the latter (oils containing
diatomite (kieselguhr),
fractions from catalytic
cracking containing abrasive
catalyst particles).
Flushing liquid consumption
300 to 500 litres/hour approx.

165

452

412.3

400.3

350

412.4 461.1

Fig. 19 Special stuffing box VSH.

1.5.1.1 Cooling Liquid for Stuffing Boxes

Treated cooling water which does not tend to precipitate salts
causing hardness out of solution should be used as cooling
liquid. The cooling water should be allowed to flow out freely
and visibly, so that it can be checked at any time in respect of
rate of flow and temperature. The temperature differential
between cooling water inlet and outlet should not exceed 10
The max. permissible cooling water outlet temperature should
not exceed 500C. The cooling water pressure should be situated
between 1 bar min. and 10 bar max.

An isolating valve should be incorporated in the cooling water
supply line, to enable the rate of flow of cooling water to be
adjusted, and the supply of cooling water to be turned off when
the pump is shut down. The cooling water should only be turned
off after the temperature of the fluid inside the pump has
dropped to below 80

0

C.

1.5.1.2 Packing the Stuffing Boxes

Caution : The pump is despatched from our works with the

stuffing boxes unpacked. An adequate quantity of packing
material is supplied loose with the pump. The stuffing box will
only be able to perform its vital function satisfactorily on
condition that it is carefully packed and properly maintained
as prescribed.

Before packing, thoroughly clean stuffing box gland (452),
packing compartment and shaft protection sleeve (524.1/.2).

5

0

C.

Fig. 20 Cutting the packing rings of length.

To cut the packing rings to correct length, use a suitable wooden
cutting jig (we can supply same on request), to ensure that the
packing rings are of the correct length and that their ring butts
come into correct contact with one another (see Fig. 20).

WK

Fig. 23 Tightening the stuffing box gland

Fig. 21 Stuffing box packing

If the packing rings are either too long or too short, the stuffing
box will not be able to perform its function properly. In the case
of asbestos-graphite packing material, the rubbing faces of
the individual rings should be lightly coated with molybdenum
disulphide before insertion in the packing compartment. The
first packing ring is then inserted and pushed home into the
compartment with the aid of the stuffing box gland.

The following packing rings are then inserted into the packing
compartment one by one, making sure that the butt joint of
each ring is offset 90

0

approx. in relation to the butt joint of the
preceding ring; the individual rings are pushed home into the
packing compartment with the aid of the stuffing box gland
(see Fig. 21 and 22). The packing rings should only be pressed
lightly against one another. They should not be inserted in the
packing compartment in such a way that a clear gap of 6 to 8
mm is left at the outer end of the compartment for the positive
guidance of the stuffing box gland.

Fig. 24 Information plate regading seal cage ring

The inserted packing rings should then be compressed
moderately with the aid of the stuffing box gland (452) and the
nuts (see Fig. 23). Then the nuts should be slackened again
by one to two complete turns, and thereafter tightened lightly
by hand. The correct and even seating of the stuffing box gland
(452) should be checked when the pump is subjected to suction
pressure, by inserting a feeler gauge between the gland (452)
and the shaft protection sleeve (524.1/.2).

In the case of the special stuffing boxes, a seal cage ring is
also inserted in the packing compartment, viz. at the centre of
the compartment (between the packing rings) in the case of
construction ‘‘VSM’’, and at the bottom of the compartment in
the case of construction ‘‘VSH’’. In these cases, an information
plate (see Fig. 20) is affixed to the stuffing box housing, showing
the position of the lantern ring. The seal cage ring must register
beneath the drilled hole in the stuffing box housing, to enable
the sealing of flushing liquid to flow through the hole and the
ring. The sealing or flushing liquid pressure should be 1 to 4
bar above the pressure reigning in the packing compartment
of the stuffing box.

Fig. 22 Insertion of packing rings with the aid of the stuffing
box gland

The packing of the stuffing boxes should be carried out with
great care, to avoid an excessively high radial pressing force
of the packing rings against the shaft protection sleeve, which
might damage the latter. If the shaft protection sleeve is scored
or grooved, even a new packing cannot be expected to last
very long in service.

6

A newly packed stuffing box should leak profusely at first. If
this leakage does not cease of its own accord after a relatively
short period of operation, the nuts on the gland should be
tightened slowly and evenly while the pump is running, until
the stuffing box only drips tightened evenly and not askew, as
otherwise the shaft protection sleeves (524.1/.2) might be
damaged (see Fig. 23).

The leakage rate in service of a soft-packed stuffing box should
amount to 3 to 5 litres/hours approx.

If the newly packed stuffing boxes start to smoke when the
pump is started up for the first time, the pump should be
switched off. If the smoking persists after the pump has been
started up again and operated several times in succession,
the nuts on the gland should be slackened slightly, or the stuffing
box should be inspected if necessary.

WK

Fig. 31 Mounted spacer-type flexible coupling

1.5.1.3 Packing Material

When selecting the packing material, make sure it is compatible
with the fluid pumped (consult the manufacturer in case of
doubt).

In steam generating plants, the asbestos-graphite packing
material specially developed for hot water service has given
good results. Packing material which has been dept in store
for a certain period has a longer service life than packing
material fresh from the packing manufacturer.

1.5.2 Mechanical Seals

Mechanical seals can be fitted as shaft seals in lieu of soft­packed stuffing boxes. If it is intended to replace soft-packed
stuffing boxes by mechanical seals after the pump has been
in service for some time, it is necessary for the pump to be
equipped with stuffing box holdings (451) for ‘‘V’’ special stuffing
boxes. It is also necessary to re-machine two tapped holes in
the cooling cover (165) for the attachment of the seal cover
(471).

1.6 Coupling

The pump on connected to the driver by a flexible coupling.
Fig. 29 illustrated the type of coupling most frequently used.

2. Mode of Operation of Pump

The fluid flows through the suction casing towards the impeller
at a given pressure. Energy is transmitted to the fluid by the
impeller, which is fitted with vanes. From the impeller, the fluid
flows into the diffuser, where kinetic energy is converted into
potential energy, increasing the pressure rise still further.

The return guide vanes arranged on the discharge end cheek
of the diffuser (171.1) guide the fluid under hydraulically
favourable conditions towards the eye of the following stage
impeller (230). This process is repeated from one stage to the
next, and the pressure rise by the same amount in each stage,
viz. by the stage generated pressure. After leaving the final
stage diffuser (171.2), the fluid flows through the discharge
casing (107) into the discharge line connected to this casing.

The generated pressure creates an axial thrust on the pump
rotor of single and multistage centrifugal pumps. By the
provision of narrow throttling gap between the impeller necks
and the casing wearing rings at either side of each impeller,
equal size lateral impeller space, and therefore almost identical
pressure conditions are created at the suction and discharge
ends of each impeller (see Fig. 34).

Fig. 29 Flexible coupling

Spacer type couplings (see Figs. 30 and 31) enable inspections
and minor repairs (e.g. the fitting of new bearings or shaft
protecting sleeves) to be carried out without removing the driver.

Fig. 30 Spacer type flexible coupling

Balance hole

Fig. 34 Axial forces acting on impeller

The balance holes in the discharge side impeller cheeks ensure
a compensation of pressures between the suction and
discharge sides of the impellers in the region situated between
the impeller hub and the throttling gap, thus again preventing
the creation of any appreciable axial thrust in this region of the
impeller. Any residual axial thrust is absorbed by the fixed
bearing in the discharge end bearing housing. This fixed
bearing also locates the axial rotor position.

7

WK

Fig. 35 Characteristics for constant pump rotational speed

As can be seen in the Fig. 35 the power absorbed by the pump
does not decrease proportionately with decreasing rate of flow,
but remains relatively high at the pump shut-off point (capacity
Q = 0).

This absorbed power is almost wholly converted into heat inside
the pump and this heating up process can lead to rapid
evaporation of the fluid inside the pump, particularly if the driving
motor is powerful and the fluid pumped is hot; this happens at
the pump shut-off point (Q = 0) and at very low rate of flow.

In order to avoid such evaporation which might damage the
pump, It is necessary to ensure a given minimum rate of flow
through the pump at all times, which removes the heat
generated.

For this purpose, an automatic recirculation valve (combined
with a non-return valve) is provided (see section 9.3.1); this
valve automatically opens a by-pass line when the rate of flow
drops below a given preset value. If such a valve is not
incorporated in the plant, the pump must not be operated below
a given minimum rate of flow, nor must it be allowed to run
against a closed discharge valve. After start up against a closed
discharge valve, the latter should be opened immediately. If
the pump handles a hot fluid or a fluid with a low boiling point
(highly volatile), or if it operates on suction lift, steps must be
taken to ensure that the fluid at the pump inlet nozzles has
attained the pressure prescribed in the Confirmation of Order,
in order to prevent vapour formation and the resulting damage
caused by cavitation particularly the disintegration of the first
stage impeller). If the back pressure is too low, the capacity of
the pump will increase unduly, and the danger than arise of
overloading and overheating of the driving motor.

Fig. 36 Slinging the ropes under the pump and driver
mounted on a combine baseplate

5. Painting

Standard construction pumps operating at temperatures below
1400C are provided with a coat of primer and a top coat of
synthetic resin base blue enamel paint (RAL 5001). If the
operating temperature exceeds 1400C, the ‘‘hot’’ pump
components, i.e. casing, pressure gauge piping and connection
rods are provided with a coat of aluminium bronze paint (RAL
9006 silver bronze). All the ‘‘Cold’’ pump components, viz. the
base-plate, bearing brackets etc. receive a coat of primer and
a top coat of blue enamel paint (RAL 5001).

Special painting to customer’s specification can be carried out
on request in accordance with the Confirmation of Order. All
bright aprts and surfaces on the pump are coated with oil
grease.

6. Condition of Equipment as Supplied

The following constructions can be supplied on request (see
Confirmation of Order for certified and binding data) :

1. Pump without baseplate (Fig. 0).

2. Pump mounted on short baseplate (Fig. 4).
(designed to accomodate pump only)

3. Pump and driver mounted on combbined baseplate
(Fig. 3).

If the pump is supplied with a short baseplate or without a
baseplate, the ropes should be slung under the connection
rods as illustrated in Fig. 37.

3. Drive

The driver is usually connected to the stub shaft at the suction
end of the pump. The direction of rotation is clockwise viewed
from the driver into the pump. On request, the drive can be
arranged at the discharge end of the pump (direction of rotation
anticlockwise) or the pump can be provided with a stub shaft
at both ends.

There are too many different types of drivers to allow them to
be described in detail here, and we would therefore refer you
to the operating instructions for the driver, published by the
driver manufacturer, which are attached.

4. Transport

If the pump is supplied as a unit bolted onto a baseplate, the
ropes for handling and transport should be slung under the
pump and driver as illustrated in Fig. 36.

Caution : When slinging the ropes for transport, never sling
them under the pump stub shafts or under the bearing brackets.

The internal interconnecting piping for the pressure relief of
the shaft seal, and any cooling liquid supply and drain lines or
sealing liquid lines, in so far as required, are already laid at
our works prior to despatch, up to the limit of the Extent of
Supply. The coupling and coupling guard are already mounted
on the pump.

When a pump is supplied mounted on a combined baseplate,
only the pump is dowelled to the baseplate, after having been
aligned with the driver.

The driver is dowelled on site with cylindrical dowel pins after
the final alignment on site. The necessary cylindrical dowel
pins are supplied loose with the pump.

8

Fig. 37 Slinging the ropes on a pump with short baseplate
Fig. 4

WK

Our erection staff will check the correct orientation of the
foundations in relation to the space axis after c;earamce fpr
erection has been given. The site management is responsible
for the zero point marking of the foundation (see ‘‘Conditions
of Erection’’).

The areas for the packing plates (shims) should now be marked
out and trued up in accordance with the foundation drawing.
Then thick packing plates should be laid in position and levelled
up with a spirit level.

The packing plates should lie flush on the foundation and be
levelled up as truly horizontal as possible to facilitate the
subsequent alignment and levelling up of the complete pumping
set as accurately as possible. The exact height is of less
importance at this stage, because any difference in heights
can be compensated by the insertion of shims of varying
thickness when the set itself is levelled up. Three point support
should be adopted for the preliminary levelling up.

Surface for shims (packing plates)

Caution :

1. The pump bearings are not filled with oil.

2. The stuffing boxes are not packed.
All apertures are plugged with PVC stoppers.

7. Accessories

As a general rule, the following items are supplied loose with
the pump :

1 set of binding bolts (only supplied loose if the pump is supplied
without a baseplate).

1 set of foundation bolts (if the pump is supplied with a
baseplate).

On request, the following items can be supplied, amongst
others :

Pressure gauge holder or pressure gauge bridge
Pressure gauge
Pressure vacuum gauge
Stop valve for pressure gauge
Coupling extractor device
1 set of shims and packing plates for levelling up
1 wooden cutting jig for packing rings
1 set of special tools

8. Installing the Pumping Set

Foundation bolt

Foundation axis

Fig. 38 Preparation of foundation

8.2 Installation and preliminary Levelling Up

The pumping set should only be placed on the foundation after
the latter has set quite firmly, and the preparations for the
foundation described above should be carefully followed.
Before placing the set on the foundation, suspend the
foundation bolts in the baseplate. Then fix the longitudinal and
lateral directions and the correct height, then carry out a
preliminary levelling up with the aid of a spirit level, and grout
in the foundation bolts.

8.3 Aligning the Coupling

If the bare pump only is supplied, i.e. the motor or gearbox are
not mounted, the flexible coupling should be pre-heated to 100-

0

C approx. in an oil bath before mounting on the stub shafts.

120
The flexible elements should be removed beforehand.

8.1 Description of Site prior to Commencement of

Erection

When our erection staff arrive on site, the pump foundation
must have been checked for dimensional conformity with our
foundation drawing data by the site management, and cleared
for erection to preceed. The foundation and its immediate
surroundings must be in a suitable condition to enable the
efficient and speedy erection of the pump and accessories to
proceed with out hindrance.

Our erection staff must be able to make use of customer’s
hoisting gear, e.g. the engine room crane etc. for transport
and erection if required.

Caution : Never drive the half coupling onto the shaft by
hammer blows. Always use a pusher device to mount it on the
shaft. (see Fig. 39).

In order to align the shafts, the pump and driver should be
pushed towards each other until the two coupling halves are
separated by the axial gap specified in the foundation or
installation drawing.

The preliminary alignment of the coupling is effected by means
of a short steel straight edge and feeler gauge.

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Wrong

Right

Fig. 39 Mounting the coupling

Straight edge

A

B

C

Max. clearance 0.04 mm

Fig. 42 Coupling alignment jig

Spacer type coupling

a

1

ab

Straight edge Gauge

E

b

1

Fig. 40 Aligning the coupling bby means of a straight edge
and gauge

Check the axial gap ‘‘E’’ at various points around the periphery,
with the aid of a feeler gauge, and place a short straight edge
across the outer diameter of the two coupling havles, forming
bridge. If the gap ‘‘E’’ remains constant around the periphery,
and if the straight edge lies flush at all points, the preliminary
alignment can be considered satisfactory (see Fig. 40 and 41).

The accurate coupling alignment requires the manufacturer of
a coupling alignment jig. This can be made from 20 x 20 flat
bar steel or similar, the jig should be attached to the shafts
(see Fig. 42).

Straight

D

edge

D

The coupling can be considered correctly aligned with the aid
of the jigs illustrated if the difference measured does not exceed

0.04 mm both in the radial and axial directions, measurements
being taken in 4 planes at 90

0

intervals. The coupling alignment
check should be repeated after the piping has been connected
to the pump.

8.4 Grouting in the Baseplate

After alignment of the coupling, the holes for the foundations
bolts and the baseplate should be grouted in with a quicksetting
cement mortar in 1:2 ratio (1 part of cement on 2 parts sand
and gravel). Make sure that all the boxes in the baseplate are
completely filled with the cement mortar and that no cavities
remain.

The foundation bolts should be tightened evenly and firmly
after the grout has set firmly. Then check with the aid of a dial
micrometer that the alignment is still correct.

8.5 Final Alignment

After all the pipelines have been connected and the direction
of rotation check has been carried out (with the pump
disconnected from the driver), the final alignment of the
pumping set should be effected. The same procedure would
be followed as for the preliminary alignment, i.e. the relevant
alignment jigs with 3 dial micrometers should be used and the
measurements previously described should be carried out at
the various shaft position (see section 8.3 ‘‘Aligning the
Couplings’’).

Gauge

Fig. 41 Aligning the spacer-type coupling by means of a
straight edge and gauge

Caution : The pump feet must be pulled tight against their
seating on the baseplate. The alignment can be considered
satisfactory if the dimensional deviations do not exceed 0.04
mm both in the case of the radial measurement and in the
case of the axial difference measurement (see section
‘‘Alignment’’).

The final measurement readings should be entered in the
system of coordinates on the erection check list. Any necessary
height adjustments should be effected by inserting shims of
appropriate thickness under the feet of the individual machines.

10

9. Piping

The main piping should be connected to the pump without
transmitting any stresses or strains onto the latter. Any
appreciable piping forces which are transmited to the base­plate via the PUMP can detrimentally affect the alignment and
the running of the pump. Such forces should therefore be kept
to a minimum at all costs.

9.1 Suction Lift Line and Positive Suction Head Line

The pipe line connected to the suction casing (106) is called
either a suction lift line or a (positive) suction head line,
depending on whether the pressure at the pump inlet is below
or above atmospheric pressure. This line should be kept as
short as possible. (see Figs. 43 and 44)

Suction lift lines should rise all the way towards the pump,
they should also be absolutely leak tight and be laid in such a
way as to prevent the formation of air pockets at any point.
(see Fig. 43).

Eccentric reducer (fitted belly down)

>0.5m

Suction strainer basket

>0.5m

Fig. 43 Suction lift line

The nominal size of the pump suction flange is no accurate
guide to the size of the suction lift line. The latter should be
sized, as a first approximation to give a velocity of 2m/sec.
approx. In principle, every pump should be equipped with its
own individual suction lift line. If this is not feasible for particular
reasons, the common suction lift line should be sized for a s
low a velocity as possible and preferably for a constant velocity
right up to the last pump on the line (see Fig. 45).

WK

Correct

Wrong

Fig. 45 Common suction lift line for several pumps

In addition, pumps connected to a common suction lift line
should be equipped with VSM stuffing boxes.

If the suction lift line is buried, it should be hydrostatically tested
at 3 to 4 bar before burial.

The same remarks as above apply to the nature and laying of
(positive) suction head lines. Horizontal lenngths of suction
head lines should however be laid with a slightly rising slope
towards the suction vessel. If it is not feasible to avoid apexes
in the suction head line, each apex should be equipped with a
vent cock. It is also advisable to avoid any appreciable length
of horizontal suction head line laid close beneath the suction
vessel because of the danger of evaporation (see Fig. 44).

9.1.1 Strainers in Suction Head Line/Suction Lift Line

Before a new pumping installation is commissioned, all the
vessels, piping and connections should be thoroughly cleaned,
flushed through and blown though. It often happens that welding
beads, pipe scal and other dirt only become detached from
inside the piping after a considerable period of service; they
must therefore be prevented from penetrating inside the pump
by the provision of a strainer in the suction head or suction lift
line. This strainer should have a free area of holes equal to 3
times the pipe cross section area approx., in order to avoid an
excessive pressure drop when foreign bodies tend to clog the
strainer.

Conical (hat shaped) strainers have given good results in
service (see DIN 4189), they should have a woven wire insert
of corrosion-resistant material with a 1.0 mm. mesh width of

0.5 mm. diameter wire. The fine strainer should precede the
coarse strainer in respect of direction of flow of the fluid. During
the initial period of commissioning, the suction pressure should
be kept under frequent observation. If the NPSH available is
found to decrease, this may be due to clogged strainers (the
pressure drop acros the strainer should be measured with the
aid of a differential pressure gauge). The strainers should then
be cleaned. (see Figs. 46 and 47).

Fig. 44 Suction head line

Unless anything to the contrary has been specified, the max.
permissible pressure drop across the strainer should not
exceed 3 meters.

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1. Strainer holder

2. Fine strainer

3. Coarse strainer

4. Pump

1

Fig. 46 Conical strainer
for suction head line

2

3

4

Fig. 47 Conical strainer with
monitoring of pressure drop.

min.

max.

9.2 Isolating Valves

An isolating valve (gate valve) should be provided in the suction
lift line, to enable the supply of fluid to a pump to be shut off if
necessary. An isolating valve should also be incorporated in
the discharge line of every pump, as close as possible to the
pump itself. This valve can be used to adjust the operating
point (rate of flow) apart from its function of isolating the
discharge line. Isolating valves in suction head lines should
only be used to isolate the line (in the event of repairs etc.).
They must always remain fully open when the pump is running.
If the pump operates under vacuum or suction lift, the isolating
valve should be provided with a sealing liquid connection or
with a closed water seal, to prevent any ingress of air into the
stuffing box of the valve stem. To facilitate venting the isolating
valves should be fitted in the line with their stems horizontal.

9.3 Non-Return Valves (in the discharge line)

A check valve or non-return valve should be incorporated
between the pump and isolating valve. Depending on the
circumstances, this can be either a check valve, or a non return
valve or an automatic recirculation valve. The object ofthe non
return valve is to prevent a reflus of fluid through the pump
when the latter stops suddenly. A blocked or leaky non return
valve may cause the pump to rotate in reverse, slackening the
shaft protection sleeves and damaging the pump.

2
15
6
18
16
21
3
8
19
11

10
20

9
23
22
13
12
17
14
1

24 25

‘‘Construction with manual
operation nozzle’’

Fig. 48 Automatic recirculation valve

The greater the flow of fluid, the higher the valve cone is lifted
by the fluid pumped. A connecting rod in the shape of a lever
the slide valve lever is connected at one end to the valve cone
and at the other end to the shut-off valve (slide valve) on the
bypass (leak-off) outlet. As the valve cone rises and falls, the
shut-off valve is actuated by this lever, and the opening of the
bypass is controlled in such a way that the bypass closes when
the rate of flow has attained a given value, and opens when it
drops below this value. The minimum flow rate is calculated
and adjusted so as to avoid any excessive overheating inside
the pump (see Fig. 49).

9.3.1 Automatic Recirculation Valve

The schroeder system automatic recirculation valve (minimum
flow device) is a safety device, the purpose of which has already
been explained in section 2 ‘Mode of Operation of Pump’. It
should always be installed immediately downstream of the
pump, always upstream of the isolating valve, and always
vertical, with the direction of flow from bottom to top (see Fig.

48).

Each automatic recirculation valve is supplied in accordance
with the operating conditions of the pump concerned.

Fig. 49

Part No. Designation

1 Bottom half of body
2 Top half of body
3 Valve cone
6 Guide shank
8 Slide valve head
9 Nozzle
10 Throttle
11 Rotary slide valve

12

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12 Lever
13 Taper grooved dowel pin
14 Bottom spider
15 Top spider
16 Cylindrical helical spring
17 Socket head cap screws
18 Socket head cap
19 Taper grooved dowel pin
20 O-ring
21*) O-ring
22 Valve
23 Cylindrical helical spring
24 Manual operation nozzle
25 Multistage throttle

0

*) Not applicable for temperature above 130
pressure rating above PN 100 (Metal to metal sealing provided).

Parts 8-13 (Complete leak-off nozzle) can be replaced
individually.

9.4 Final Coupling Check

After completion of the piping assembly, the coupling alignment
should be checked once more (See Section 8.3 ‘‘Aligning the
Coupling’’). It must be possible to rotate the pump rotor without
effort by hand at the coupling, when the stuffing boxes are not
packed. If the alignment is satisfactory (no misalignment having
taken place), the driver can be dowelled with cylindrical dowel
pins.

9.5 Measuring Instruments

Each pump should be equipped with two pressure gauges,
one at suction nozzle and the other at the discharge nozzle;
their measuring range should be suitable for the prevalent
pressure conditions, and they should be provided with a stop
cock or stop valve. If the suction conditions demand it (e.g.
suction lift operation), the gauge on the suction nozzle should
be pressure vacuum gauge (measuring instruments can be
supplied by us on request see Fig. 50).

C and valve

Even a relatively short start up run in reverse rotation may
result in damage to the pump. The overspeed trip check
of the turbine or turbine driven pumps should also be
carried out with the turbine disconnected from the pump.

2. Check correct coupling alignment again.

3. Dismantle pump bearings, clean them and reassemble
them (as described in section 11, ‘‘Dismantling the
Pump’’).

4. Fill-in oil, or check grease fill respectively.

5. Pack the stuffing boxes (see section 1.5.1 ‘‘Stuffing
Boxes’’).

10.2 Start-up

1. Check oil level in pump bearings, if necessary top up the
oil fill until oil starts pouring out of the over flow hole.

2. Check condition of stuffing boxes (451.1 / 451/2). The
stuffing box gland should penetrate deep enough in the
stuffing box to ensure positive guidance, and must not be
tightened askew (see section 1.5.1 ‘‘Stuffing Boxes’’).

3. In the case of a mechanical seal with internal circulation,
open flow controller fully (only applies to the initial start­up).

4. Turn on cooling liquid supply and check that it flows away
freely.

5. Open suction valve fully.

6. Leave isolating valve in discharge line closed for the time
being.

7. The pump must be completely primed with the product
pumped. Before it is started up for the first time, the pump
should be vented through the connection on the discharge
pressure gauge, or through the vent valves, if provided.
The discharge line should also be vented through valves
situated at the apex of the line.

Fig. 50 Arrangement of measuring instruments

10. Commissioning

10.1 Preliminary Remarks regarding Commissioning

If the initial start up does not take place immediately after the
erection of the pumping set, but only weeks or even months
later, it will be necessary to carry out the following checks once
again before start up :

1. Renewed direction of rotation check of driver with pump
disconnected from the driver.

8. Open the shut off valve on the minimum flow line of the
automatic recirculation valve and lock it open, to prevent
unintentional closure. If the automatic recirculation valve
is equipped with a manual operation line, open the valve
in this line.

If the pump is only equipped with a manually controlled
minimum flow (by pass) line, open the isolating valve in
this line.

If a check valve or non return valve is incorporated and if
the pump is to be started up against an open discharge
valve, make sure that the non return valve is closed as a
result of the back pressure (e.g. the boiler pressure). If
the full back pressure does not reign at the time of start
up the pump should only be started up against a closed
discharge valve.

9. Check suction pressure and temperature. Check whether
the saturation condition of the fluid pumped reigns inside
the pump with the aid of the saturation curve. No vapour
formation must be allowed to take place inside the pump.

10. When starting up for the first time, and also after a
prolonged plant shutdown, start up the driver with the
pump coupled to it, then switch off the driver again
immediagely. Check that the rotor runs down to a standstill

13

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smoothly and lightly, and check that the pump bearings
are being supplied with oil. The pump rotor must not stop
with a sudden jerk.

11. In the case of a turbine driven pump, run the pump up to
full sped rapidly.

12. Watch the discharge pressure, to make such the pump
attains the prescribed discharge pressure.

13. If applicable, close the manually operated minimum flow
line when the operating rotational speed has been
attained. Check whether minimum flow line becomes
warm.

14. Adjust rate of flow of cooling liquid for the mechanical
seal by means of the flow controller. The temperature at
the mechanical seals should not exceed 70

0

C.

15. Open isolating valve in the discharge line.

Caution : If the pump is commissioned on hot fluid, the casing
will heat up more rapidly than the connection rods (905)
because of its direct contact with the fluid pumped. The casing
will become longer as a result of thermal expansion. The pre­stressing of the connection rods will increase and the surface
pressure (contact pressure) on the flat gaskets will attain a
maximum value. Under such stress conditions, the gaskets
which are still new will bed themselves down. When the pump
has warmed up all over, the connection rods (905) may suffer
such a reduction in prestressing that the pump may start leaking
at the stage casings, especially in the case of pumps with a
large number of stages. In order to avoid such leakage, the
connection rods (905) should be tightened up after the first
few ‘‘hot’’ starts on a new or reconditioned pump.

10.3 Operation and Supervision of Pump

1. Pumps operating at constant speed may usually be
operated at the point of optimum efficiency, at total heads
up to 90% of design head providing that suction head
and the motor horsepower are adequate.

2. Pumps operating at constant speed may usually be
operated within the range indicated in the pump operating
diagram below. It should be noted that the throughout
which can be achieved decreases with decreasing speed
and pressure (see Fig. 51).

3. When filling the boiler, the operating limits specified in 1
and 2 above should not be exceeded i.e. the discharge
valve should be partially closed to ensure that the pressure
does not fall below the minimum discharge pressure
corresponding to the particular speed or capacity at which
the pump is operated at the time. If the rate of flow drops
below the minimum flow, the minimum flow device starts
operating. Any prolonged operation within the response
range of the minimum flow device should be avoided as
far as possible, because this will cause premature wear
on the control and throttling organs.

10.4 Shutting the pump down

1. Close isolating valve (gate valve or globe valve) in the
discharge line. If applicable, check the opening point of
the minimum flow device from time to time.

2. Switch off driver and watch the pump run down smoothly
to a standstill. The pump rotor should not stop with a
sudden jerk.

3. If applicable, turn off the sealing, circulation or flushing
liquid.

4. The cooling liquid supply can be partially throttled, but it
should only be turned off completely when the temperature
inside the pump measured at the pump nozzle, has
dropped below 80

0

C. The suction valve should remain
open unless the pump is being taken out of service of a
prolonged period and it being drained.

10.5 Preserving the Pump

If the pump is taken out of service for a prolonged period, it is
advisable to dismantle it completely. Proceed as described in
section 11 ‘‘Dismantling’’. All components should be thoroughly
cleaned, dried and all bright parts coated with grease.
Thereafter the pump should be reassembled. All apertures on
the pump should be plugged with wooden stoppers soaked in
oil or blanked off with wooden cover plates fitted with O-rings.
A sachet filled with silicagel (silicagel absorbs moisture) should
be attached to the inside faces of the oil soaked wooden cover
plates on the suction and discharge nozzles (i.e. inside the
nozzles).

The packing should be removed from the stuffing box
compartments and these should be sealed by oil-soaked
wooden half tubes, each provided with two O-rings, in order to
prevent the penetration of moisture (not applicable to pumps
fitted with mechanical seals).

Fig. 51 Pump operating diagram

Caution : Only use acid free oils and greases when preserving
the pump.

Fig. 52 Transport frame, Pump feet at shaft centreline heigh

14

10.6 Sending the Pump back to our Works

If the pump is sent back to our Works for repairs or overhaul, it
should be despatched completely assembled in order to
prevent any possible damage to the sealing faces during
transport. All pipe connections and flanges should be plugged
or blanked off, after the pump has been drained. The pump
should be securely mounted on a transport frame for despatch
(see Figs. 52 and 53).

WK

Fig. 55 Pulling off the coupling hub

2. Remove bearing cover (360).

3. Bend back tab washer between ring nut of adaptor sleeve
and cylindrical roller bearing (322) (see Fig. 56).

Fig. 53 Transport frame, Pump feet at bottom

11. Dismantling the Pump

11.1 Preparations prior to Dismantling

1. Close all isolating valves in the suction and discharge
lines, and also, if applicable, in the cooling liquid, sealing
liquid or flushing liquid lines, and drain the pump via the
drain apertures (6B) in the suction and discharge casings
(106 and 107).

2. Dismantle and remove cooling liquid, sealing liquid or
flushing liquid lines.

3. Pull out stuffing box gland (452) and remove stuffing box
packing (461.1).

4. Disconnect coupling (see section 1.6 ‘‘Couplings’’). Check
pump alignment at the coupling and make a note of the
measurements (see section 8.3 ‘‘Alignment’’).

5. If the pump is to be dismantled completely, unscrew the
fixing bolts on the suction and discharge lines and on the
pump feet, and remove the pump from the baseplate.

6. Drain off the oil fill in the bearing housing by unscrewing
drain plug (903.4/.5).

11.2 Dismantling the Bearings

Fig. 56 Bending back the locking washer

4. Slacken withdrawal nut of adaptor sleeve (52.1) by a few
turns (see Fig. 57).

11.2.1 Dismantling the Drive End Bearing

1. Pull off the half coupling with the aid of an extractor (see
Figs. 54 and 55).

Fig. 54 Wheel puller

Fig. 57 Pulling off the coupling hub

5. Loosen adaptor sleeve (52.1) on shaft (210) by gentle
taps on the end face of the withdrawal nut.

15

Fig. 58 Forcing out the inner components of the cylindrical
roller bearing

6. Pull out inner race of cylindrical roller bearing (322)
together with adaptor sleeve (52.1) from bearing housing
(350) (see Figs. 58 and 59)

WK

Fig. 61 Removing the bearing housing (350) together with
outer race of cylindrical roller bearing (322)

Fig. 59 Dismantled inner components of cylindrical roller
bearing

7. Unscrew and remove hex. nuts (920.2) from studs bolts
(902.1) in the suction casing (106) in order to dismantle
the bearing housing and stuffing box housing (see Figs.
60 and 61).

Fig. 60 Forcing off the bearing housing

Fig. 62 Stripping off the splash ring

8. On pump size 150 which is fitted with a cylindrical roller
bearing without adaptor sleeve, the bearing housing (350),
including the outer race of the bearing and the other
distance ring (543) are removed after unscrewing the hex.
nuts (920.4), then the inner race of the bearing and the
inner distance ring (525.4) are pulled off the shaft, and
the circlip (932) removed.

11.2.2 Dismantling the End side Bearing

11.2.2.1 Standard Bearing Construction

1. Remove bearing end cover (361) together with gasket
(400.4).

2. Unscrew hex. shaft nut (920.4) and remove it from the
shaft.

3. Unscrew and remove hex. nuts (920.2) from studs (902.1)
in discharge casing (107), in order to dismantle the bearing
housing and stuffing box housing.

4. Force off bearing housing together with deep groove ball

16

bearing (321) by means of loan forcing screws until the
bearing housing and bearing can be pulled off the shaft
without effort.

5. Inspect condition of deep groove ball bearing (321) and if
necessary remove it form bearing housing (350).

6. Strip splash ring (507) off the shaft.

11.2.2.2 Heavy Duty Bearing Construction

1. Remove bearing end cover (361) including O-ring (412.7).

2. Unscrew shaft nut (923) and remove it from the shaft
together with lubricating ring (644).

3. Unscrew hex. nuts (920.2) from studs (920.3) in outlet
cover (107), in order to dismantle bearing housing (350).

4. Force off (with the aid of forcing screws) bearing housing
(350.2) together with angular contact ball bearing (320),
inner distance ring (525.8), outer distance ring (543), guide
bush (508) and lubrication ring (644), and pull the bearing
assembly off the shaft with the aid of an extractor.

5. Remove distance bush (525.5), circlip (932) and splash
ring (507) from the shaft.

6. Inspect condition of angular contact ball bearing (320)
and if necessary remove it form bearing housing (350.2).

11.3 Removing the Shaft Seal

11.3.1 Soft-packed Stuffing Box Construction

WK

Fig. 64 Slackening shaft protection sleeve (524.2)

11.4 Dismantling the Pump Body

1. The stage casings (108) should be numbered
consecutively in respect of their positions in relation to
one another before dismantling, to ensure that the suction
casing (106), the stage casing (108) and the discharge
casing (107) are all reassembled in the correct sequence
in relation to one another during reassembly (see Fig.

68).

1. Pull stuffing box gland (452) off the shaft.

2. Force off and remove stuffing box housing (451). On
pumps equipped with cooled stuffing boxes, force off and
remove the stuffing box housing (451) including cooling
cover (165) (see Fig. 63).

Fig. 63 Removing the stuffing box housing (451)

3. Slacken shaft protection sleeve (524.2) and remove it from
shaft (210) (see Fig. 64)

Fig. 68 Identification of casing components and removal of
tie rods

2. Unscrew nuts (920.1) at discharge end or connection rods
(905) and pull the connection rods out of the suction and
discharge casing (see Fig. 68).

3. Underpin the pump at the stage casing (108) with wooden
blocks or an erection trestle, so as to free the component
which is to be dismanntled next.

4. Force discharge casing (107) together with diffuser/last
stage (171.2) off stage casing (108) and lift it off (see Fig.
69 and 70).

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Fig. 69 Forcing off the stage casing

Fig. 70 Lifting off the stage casing

5. Dismantle in sequence impellers (230), stage casings
(108) together with diffusers (171.1), keys and stage
sleeve (521) (see Figs. 71 and 72)

Fig. 72 Slackening and removing the stage casing

6. When the last stage casing (108) has been dismantled,
pull shaft (210) together with last impeller (230), spacer
sleeves (525.1) and shaft protection sleeve (524.1) out
of the suction casing (see Fig. 73).

Fig. 73 Removing the shaft together with first stage
impeller

7. Pull impeller (230), spacer sleeve (525.1) and shaft
protection sleeve (524.1) off the shaft (see Fig. 74).

Fig. 71 Forcing off the impeller

Fig. 74 Dismantled shaft with impeller spacer sleeve and
shaft protection sleeve.

8. Stack the stage casings on top of one another in correct
order. The contact faces should be protected by wooden
strips or thick cardboard during stacking, to avoid any
damage. (see Fig. 75)

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Fig. 75 Stacking the stage casings on top of one another

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Fig. 76 Inserting the outer race of the roller bearing

Observe the greatest cleanliness when mounting the
bearings (322). If the existing bearings are to be used
again, they should be cleaned with petrol gasoline or
benzol. After washing, they should immediately be
sparyed with oil.

11.5 Inspection of individual Pump Components

1. Shaft (210)

Check true running (out-of-round) between centres on a
lathe. Max. permissible out-of-round (shaft whip) : 0.03
mm. In principle, a bent shaft should never be straightened
out, either warm or cold, but replaced by a new shaft if
the permissible shaft whip is exceeded.

Caution : Make sure the shaft is accurately centred on
the lathe as otherwise erroneous measurement results
will be obtained.

2. Stage Casings (108)

Examine al contact faces for flawless condition. The plane
parallelism of the contact faces must be checked at 4
points around the circumference. The deviation should
not exceed 0.05 mm. Touch up any damage contact faces
on a lathe. The surface roughness must not exceed
Ra = 1.6 m.

3. Bearings (322)

The bearings should be replaced by new ones even if
there are only slight discolorations or rust specks, or signs
of damage on the contact faces tracks and ball or rollers.
The outer race of the cylindrical roller bearing should be
inserted as illustrated in Fig. 76.

4. Impellers (230) spacer sleeve suction/discharge (525),
stage sleeve (521), Casing Wearing Rings (502) and
Diffusers (171).

Inspect the impellers (230) for signs of damage by solids
entrained with the fluid pumped.

540.2 503 171.2 400.2 541 521 106 210
107

412.2 230 108 171.1 502 540.3

525.2

525.1

Fig. 77 Alternative material construction in chrome steel
throughout (e.g. CA6NM)

The impeller necks -- in the case of material construction
CA6NM (chrome steel construction throughout) these are
provided with impeller wearing rings (503) -- and the
casing wearing rings (502, stage sleeve diffusers in the

As new clearance Max. permissible clearance

for material alternative value for material alternative

Chrome steel Chrome steel

C.I. Bz throughout C.I. Bz throughout

and bronze and bronze

mm on dia. mm on dia. mm on dia. mm. on dia.

Casing Wearing ring Impeller neck 0.30 0.40 1.0 1.0

Diffuser -- stage sleeve 0.30 0.35 1.0 1.0

Discharge casing -- spacer sleeves 0.30 0.35 1.0 1.0

Suction head

Shaft -- Suction casing 1.0 1.0 2.0 2.0

operation

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case of chrome steel construction throughout the latter
and provided with inter stage bushes (541) should all be
examined for signs of radial galling (seizure). The spacer
sleeve (525.1) should be examined for signs of galling in
the suction casing (see Fig. 77). If any galling has been
ascertained, and if it can be eliminated by touching up on
a lathe, the increase in clearance which results must not
exceed the max. permissible values listed in Fig. 78 ‘‘Rotor
Clearances’’. If the touching up work on the components
results in a clearance in excess of the max. permissible
value, new components should be fitted, and the ‘‘as new’’
clearances listed in Fig. 78 should be re-established.

The increase in clearance must be adjusted to the same
valve at all the throttling gaps on the pump, in principle if
the clearances have been exceeded at one or more places
inside the pump body, and new wear parts have to be
fitted at those places, it is advisable to fit new parts at all
the other places as well.

Assembly from Drive End

Slip shaft protection sleeve (524.1) onto the shaft without O­ring (421.3) and pull it tight against the shaft shoulder. Mount
coupling half with the aid of a pusher device.

Assembly from End Side

Mount spacer sleeve (521), keys and impellers (230) of the
remaining stages onto the shaft in their correct sequence.

Caution : Remember to mount the impellers in accordance
with their correct stage sequence.

Slip spacer sleeve (525.2) shaft protection sleeve (524)
respectively onto shaft (921) without O-ring (412.3), and pull
them tight against the hub of the last stage impeller (230).

5. Shaft Protection Sleeves (524.1/.2)

These may only be touched up very slightly, if the damage
is more than superficial, new shaft protection sleeves
should be fitted.

6. Cooling Compartments of Stuffing Box Housings (451)

If applicable, and if a cooling liquid supply is connected
to them, inspect the compartments and clean them.

reverse sequence to the assembly described above.

Fig. 79 Rotor assembly for dynamic balancing

12. Assembly of Pump

12.1 Preparations prior to Reassembly

Before reassembly of ring section pumps, the axial face-to­face length ‘‘E’’ of each stage casing (108) and of the
corresponding impeller (230) with stage sleeve (521) must be
measured. Any discrepancy in lengths must be compensated
by machining the stage sleeve (521) only, and the end result
must be E1 = E2 taking the thickness of glat gasket (400.2)
into account (see Fig. 80).

If machining of the stage sleeve is required, it should be
shortened at both end faces in one and the same clamping on
the machine too. The permissible end face wobble (deviation
from plane parallelism) is 5 m. Make sure not to damage the
contact faces on the casing components, diffusers impellers,
spacer sleeves and stage sleeves before and during assembly.
All pump components, particularly the end contact faces, should
be thoroughly cleaned. If new impellers are fitted, or if the old
ones are touched up, the rotor must be balanced dynamically.

12.2 Assembling the Pump Body

1. Before assembly of the rotor components, coat the shaft
(120) with molybdenum disulphide.

E

1

7. Coupling

If the flexible elements show signs of wear after a
prolonged period of operation, replace same by new ones
in good time.

11.6 Dynamic Balancing of Pump Rotor

If certain rotor components are replaced by new ones or are
touched up, or if a new shaft is fitted, the pump rotor of pump
sizes 40 to 100 must be subjected to an out-of-round check,
and in addition, the pump rotor of pump sizes 125 and 150
must be dynamically balanced, if possible at max. operatings
speed, but in any event at 1000 1/min. The max. permissible
residual eccentricity should not exceed 5 m.

For the dynamic balancing test, the rotor should be assembled
as follows :

Before dynamic balancing, the pump rotor should be checked
for out-of-round in the region of the impeller necks (230), of
the spacer sleeves and distance stage sleeve (525.1 and 521)
and of the bearings (see Fig. 79). The measured out-of-round
value at any of these places should not exceed 0.03 mm. Before
final assembly in pump, the rotor must be dismantled again, in

E

2

Fig. 80 Measuring the stages

2. Slip the shaft protection sleeve (524.1) onto shaft (210)
after inserting O-ring (412.3) and pull it tight against the
shaft shoulder. Mount spacer sleeve (525.1), key and first
stage impeller (230) onto shaft (210) (see Fig. 81).

20

Fig. 81 Shaft with first stage impeller

3. Insert shaft (210) together with spacer sleeve (525.1) and
impeller (230) into discharge casing (106) (see Fig. 82).

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Fig. 84 Mounting the stage casings

6. After assembly of each individual stage, check the total
axial clearance ‘‘Sa 1 + Sa 2’’ of the pump rotor (approx.
6 mm. see Fig. 85).

Fig. 82 Shaft with first stage impeller inserted into suction
casing

Fig. 83 Mounting the impeller

4. Mount stage casing (108) together with inserted diffuser
(171.1) and flat gasket (400.2), and slip stage sleeve (521)
onto the shaft (see Fig. 84).

Sa2

Sa1

Fig. 85 Checking the total axial clearance.

7. Mount discharge casing (107) with inserted last stage
diffuser (171.2) and O-ring (412.2) (see Fig. 86).

5. Mount all the following stages in similar fashion each stage
consists of stage casing 9108), diffuser (171.1), casing
wearing ring (502), flat gasket (400.2), impeller (230), key
and stage sleeve (521). Underpin the stage casings (108)
in turn after assembly (see Fig. 84).

Fig. 86 Inserting the diffuser in the discharge casing

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Size Number Torque Number Torque

of stages of stages

40 1-10 7.5 kpm 11-16 8.0 kpm

50 1-10 8.5 kpm 11-15 10.0 kpm

65 1-10 12.0 kpm 11-14 15.0 kpm

80 1-8 20.0 kpm 9-12 23.0 kpm

100 1-8 25.0 kpm 9-11 27.0 kpm

125 1-6 30.0 kpm 7-10 32.0 kpm

150 1-6 35.0 kpm 7-8 37.0 kpm

Fig. 87 Tightening torque for the connection rods

1kgm = 1 kpm

8. Insert tie rods (905) with nuts (920.1) and washers (550)
from the suction end.

9. At the suction end, screw on at the hex. nuts (920.1) on
connection rods (905) and screw them down to median
position. Insert the tie rods (905) from the suction end,
after having slipped on the washers.

9a. PUmps which operate under conditions of extreme

temperature fluctuations (in excess of 50

0

C within a 30
minute interval) can be subjected to unequal thermal
expansion at the casings and tie rods, which can result in
leakage. In order to compensate these expansions, a
stack of cup springs should be inserted between the nut
and suction casing on each connection rod. The number
of cup springs in the stack will depend on the compression
pressure required, and is determined by the pump
manufacturer (see Fig. 88).

by hand with a standard short spanner to ensure intimate
contact of the stage casings (108) at their sealing faces.

11. Slip the spacer sleeve onto the shaft until it abuts against
the hub of the last stage impeller.

12. Place the pump on the baseplate. The pump feet must
seat flush on the baseplate. Tighten hex. nuts (920.1) on
the tie rods at the discharge end evenly on the cross.

13. Tighten nuts (920.1) on the tie rods (905) at the discharge
end. Then slacken the nuts at the discharge end again
until the seating is loose, and tighten them again by hand
with the aid of a short hammering spanner until contact is
established. Then tighten the nuts firmly with the aid of a
torque spanner (see Fig. 87).

12.3 Assembly of Shaft Seal

12.3.1 Pump construction with Soft packed Stuffing Box

1. Slip shaft protecting sleeve (524.2) onto shaft (210) after
insertion of O-ring (412.3), and pull it tight against spacer
sleeve (525.2) (see Fig. 89).

483 520.1 550.1

Part No. Designation
106 Suction casing
483 Spring cage

520.1 Sleeve

550.1 Washer
905 Tie rod

920.1 Hex. nut
950 Stack of cup springs

920.1 950 106 905

Fig. 88 Stack of cup springs.

9b. The washer (550.1), sleeve (520.1), stack of cup springs

(950) and spring cage (483) are all mounted on the tie
rods (905) between the suction casing (106) and the hex.
nut (920.1). The cup springs should be lightly coated with
oil before insertion. The hex. nut (920.1) should be
screwed on by hand. The tie rods (905) should be fitted
as described under point 10 below. The hex. nut (920.1)
at the suction end should be tightened until abbutment is
achieved.

Fig. 89 Mounting the shaft protection sleeve

2. Mount stuffing box housing (451) with flat gasket (400.3).
In the case of pumps equipped with cooled stuffing boxes,
mount the stuffing box housing (451) together with cooling
cover (165) (see Fig. 90).

If the pump should become slightly distorted by uneven
tightening, the hex. nuts (920.1) at the suction end should
be slackened slightly.

10. At the discharge end, the screw threads of the tie rods
and the washers should be coated with molybdenum
disulphide. The hex. nuts (920.1) should bbe tightened

Fig. 90 Mounting the stuffing box housing

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3. Slip the stuffing box gland (452) loosely on shaft (210)
but do not insert it in the stuffing box compartment.

4. Slip splash ring (507) onto the shaft.

12.4 Assembly of Bearings

12.4.1 Assembly of End Side Bearing

Standard Bearing Construction 1

1. Mount splash ring (507) onto shaft (210).

2. Slip bearing housing (350) onto the shaft and onto the
studs on discharge casing (107), and fasten it with the
nuts (920.2) (see Fig. 107).

920.4 321 350 903.12 400.4 920.4 350 525.4

361

3. Slip spacer sleeve (525.5) onto the shaft until it abuts
against circlip (932).

4. Slip inner guide bush (508) and lubricating (644) onto the
shaft.

901.3 361 913 350.2 412.7 507

903.5

412.7

(13B)

400.5

644

160

543

525.8

901.4

720.3

644

(8B)

360.2

210350508320320923

525.5

902.3

Fig. 109 Heavy duty bearing bracket construction on pump
size 150.

400.4

903.4
(13B)

507

932321543361

507

Fig. 107 Bearing
construction, pump
sizes 40 to 125

Fig. 108 Bearing
construction, pump size 150

3. Mount deep groove ball bearing (321).

4. Screw hx. shaft nut (920.4) onto the shaft and tighten it.

5. Mount bearing end cover (361) and gasket (400.4).

6. Seal the oil drain apertures (13B) by means of threaded
plug (903.4).

7. In the case of pump size 150, assembly should proceed
as follows :

Mount splash ring (507), circlip (932) and inner spacer
sleeve (525.4) on the shaft.

Insert deep groove ball bearing (321) and outer spacer
sleeve (543) into the bearing bracket (see Fig. 108).

Mount bearing bracket (350) together with inserted
components.

Caution : The angular contact ball bearings must be mounted
in ‘‘X’’ arrangement. To facilitate mounting, it is advisabble to
pre-heat the angular contact ball bearings in an oil bath before
they are slipped onto the shaft.

5. Mount inner angular contact ball bearing (320), inner
distance ring (525.*0, outer spacer sleeve (543) and outer
angular contact ball bearing (320) onto shaft (210).

6. Screw shaft nut (923) onto shaft, and pull it tight. Insert
lubricating ring (644).

7. Mount bearing end cover (361) with O-ring (412.7) and
pull it tight with the aid of hex. bolts (901.3).

12.4.2 Assembly of Drive End Bearing

1. Mount splash ring (507) on shaft (210).

2. If necessary, insert outer race of cylindrical roller bearing
(322) in the bearing housing (see Fig. 76).

731.2 322 400.4 901.2

350

Mount lock washer and hex. shaft nut (920.4) on the shaft.

Pull the nut tight and lock it with the aid of the lock washer.

Mount bearing end cover (361) with gasket (400.4).

Heavy Duty Bearing Construction (see Fig. 109).

1. Mount splash ring (507) and circlip (932) on the shaft.

2. Slip bearing housing (350.2) together with cover (160)
and bearing cover (360.2) onto the shaft and studs (902.3)
on the discharge casing and fasten it with the nuts (920.2).

507 52-1 360 210

Fig. 110 Bearing construction, pump sizes 40 to 125

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3. Mount bearing housing (350) together with outer race of
cylindrical roller bearing (322) and tighten hex. nuts
(920.2) evenly (see Fig. 111).

Fig. 111 Mounting the bearing housing

4. Slip adaptor sleeve (52-1) together with bearing inner race,
lock washer and withdrawal nut onto shaft (210) until the
rear end face of the inner bearing race lies in the same
plane as the outer end face of the oter race of cylindrical
roller bearing (322). Then tighten the withdrawal nut and
make sure that the components of the cylindrical roller
bearing do not slide out of position in relation to each
outer whilst the nut is being tightened (see Figs. 112 and

113).

5. Bend down the tabs on the locking washer (see Fig. 114).

6. Mount bearing cover (360) and flat gasket (400.4) (see
Fig. 115).

Fig. 112 Mounting the inner race of the cylindrical roller
bearing with adaptor sleeve

Fig. 113 Tightening the withdrawal nut

7. On pump size 150, assembly should proceed as follows
(see Fig. 116).

507

525.4 350 360

932 322 543

Fig. 116 Bearing construction, pump size 150

Mount splash ring (507) and circlip (932) on the shaft.
Insert outer race of cylindrical roller bearing (322) and
outer distance ring (543) in the bearing housing. Mount
bearing housing (350).

Slip inner distance ring (525.4) and bearing inner race
(322) onto the shaft.

Mount locking washer and shaft nut (920.4) on the shaft.

Pull nut tight and lock it with the locking washer.

Mount bearing cover (360) and gasket (400.4).

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8. Mount coupling hub on the shaft with the aid of a pusher
device.

9. Align pump at the coupling (see section 8.3, ‘‘Coupling
Alignment’’).

10. Pull fixing bolts tight on pump feet (see section 8.5, ‘‘Final
Alignment’’).

11. Pack the stuffing boxes in accordance with section 12.3.1
‘‘Assembly of Shaft Seal’’.

12. Connect all the pipelines to the pump.

13. Carry out a final coupling alignment check in accordance
with section 8.5 ‘‘Final Alignment’’.

14. Fill the bearing housing (350) with oil (see sections 1.3
‘‘Bearings’’ and 1.4 ‘‘Lubrication’’).

15. Open isolating valve in suction line fully.

16. Start up the pump (see section 10 ‘‘Commissioning’’).

13. Operating Troubles, Causes and

Remedies

Caution : Before remedying operating troubles, check all
measuring instruments used for reliability and accuracy.

13.1 Operating Troubles Cause and suggested remedy see

section 13.2 & 13.3

1. Pump fails to deliver liquid 1, 2, 3, 4, 5, 6, 8, 12,

13

2. Pump delivers insufficient 1, 2, 3, 4, 5, 8, 12, 13,
liquid 19, 20, 21

3. Total head is too low 3, 4, 5, 7, 8, 10, 12, 19,

20, 21

4. Sudden interruption of 1, 2, 3, 4, 9, 11, 13
delivery shortly after start-up

5. Absorbed power is 6, 7, 9, 10, 17, 19
excessively high

6. Excessive leakage at 14, 16, 18, 22, 23, 24,
stuffing box 28, 29

7. Life of packing is too short 14, 16, 18, 22, 23, 24,

25, 26, 27, 28, 29

8. Pump vibrates or runs noisily 2, 3, 4, 11, 13, 14, 15,

16, 17, 18, 20, 24, 32,
33

9. Life of bearing is too short 14, 16, 17, 25, 31, 32,

33, 34

10. Excessively high temperature 1, 3, 4, 7, 9, 11, 13, 14,
inside the pump. 16,
Rotor fouls the casing or 18, 19, 20, 24, 30, 32
seizes

11. Too high a rate of leakage 14, 16, 18, 24, 25, 35,
liquid at the mechanical seal 36, 37, 38, 39, 40
or too short a mechanical
seal life

13.2 Cause of Damage (the numbers listed below

correspond with the code numbers of section 13.1).

Faults at the Suction End

1. Pump not properly vented, air pocket in suction line,
vapour bubble at suction end, lines not properly vented.

2. Pump or suction line incompletely primed with fluid.

3. Insufficient pressure differential between suction pressure
and vapour pressure, NPSH required is not attained
(observe rate of pressure decrease).

4. Mouth of suction line too close to surface of liquid level in
the suction vessel, or liquid level in vessel too low.

General Faults in the Installation

5. Rotational speed to low, or rate or minimum flow through
by-pass excessive.

6. Rotational speed too high.

7. Reverse rotation.

8. Total head required for the system is higher than total
head generated by the pump at duty point (back pressure
too high).

9. Total head required for the system is lower than total head
generated by the pump (pump operates beyond the
performance limit curve).

10. Specific gravity of fluid pumped is different from figure
specified originally (different operating temperature).

11. Operation at very low rate of flow (fault in minimum flow
device, rate of minimum flow is too low).

12. Pumps cannot possibly operate in parallel under these
conditions.

Mechanical Faults

13. Foreign bodies lodged in impeller.

14. Pump misaligned or incorrectly aligned, or shifting of
foundation.

15. Resonance, or interference by other machines via the
foundation.

16. Shaft is bent.

17. Rotating elements foul the stationary elements, pump runs
very rough.

18. Bearings badly worn.

19. Casing wearing rings badly worn.

20. Impeller damaged or disintegrated.

21. Fault casing seal (excessive internal loss at throttling gap,
rotor clearances exceeded due to wear), so that an
excessive loss arises or water leaks through the casing
partition. Water leaks out of metallic sealing face to
atmosphere.

22. Shaft or shaft protection sleeves worn or scored, O-ring
damaged.

23. Stuffing box badly packed. Packing material of unsuitable
quality.

24. Shaft chatters because bearings are worn or because
shaft is misaligned.

25. Rotor vibrates.

26. Stuffing box gland is tightened excessively, no fluid
available to lubricate the packing.

27. Defect in cooling liquid supply to water-cooled stuffing
box gland.

28. Excessive clearance gap between stuffing box gland and
shaft protection sleeve. Packing is squeezed into gap
beneath the gland.

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29. Dirt or sand in cooling liquid fed to stuffing box gland
causes scoring of shaft protection sleeve.

30. Excessively high axial thrust.

31. Insufficient quantity of oil in bearing housing, unsuitable
oil quality, dirty oil, water in the oil.

32. Faulty bearing assembly (damage during assembly,
wrong, assembly).

33. Dirt in the bearings.

34. Ingress of water into bearing housing.

35. Rubbing faces of mechanical seal worn or scored. O-rings
damaged.

36. Seal incorrectly assembled. Materials unsuitable.

37. Surface pressure in sealing gap too high, no fluid available
for lubrication and cooling.

38. Fault in cooling liquid supply system to mechanical seal.

39. Excessively large gap between cooling housing and
spacer sleeve. Temperature in the cooling circuit rises
excessively.

40. Dirt in cooling circuit of mechanical seal leads to scoring
of mechanical seal rubbing faces.

13.3 Suggested Remedies

If, after a breakdown has occurred, one of the cause listed in
section 13.2 has been established as the cause, and the matter
has been put right or the cause of the trouble eliminated, it is
recommended, prior to recommissioning the set, to check the
effortless rotation of the pump rotor by hand, with the driver
disconnected (unless the pump had to be dismantled in any
case, because of the damage). Check that the pump runs
smoothly and quietly after recommissioning.

Cause 1. Open vent valves or pressure gauge vent screws,

open isolating valves in minimum flow device
circuit. Check layout of pipelines to ensure that fluid
flows smoothly.

Cause 2. Prime pumps and piping again, and vent them

thoroughly. Check layout of pipelines.

Cause 3. Check isolating valve and strainers in suction line.

The instrument readings taken must be accurate.
Consult manufacturer.

Cause 4. Check water level in reservoir and examine

possibility of altering it. Raise water level, alter
mouth of suction line. The nozzle should not project
too high inside the reservoir, and it should be
shaped so as to promote favourable flow
characteristics.

Cause 5. Increase speed, if pump it turbine-driven. Refer to

manufacturer, if pump is motor-driven. Check
operation of minimum flow device.

Cause 6. Decrease speed, if pump is turbine-driven. Refer

to manufacturer, if pump is motor driven.

Cause 7. Cross over two phase leads on the motor.

Cause 8. Increase rotational speed. Fit larger diameter

impellers. Increase number of stages. Refer to
manufacturer.

Cause 9. Adjust pressure conditions by means of discharge

valve. Alter rotation speed, alter impeller diameter.
Refer to manufacturer.

Cause 10. Check temperature of fluid pumped, take steps

outlined in 9, above.

Cause 11. Check operation of minimum flow device. Refer to

manufacturer.

Cause 12. Check condition of individual machines. Refer to

manufacturer.

Cause 13. Clean out pump, check condition of suction system

(check suction line and strainers).

Cause 14. Realign pumping set when cold.

Cause 15. Refer to manufacturer.

Cause 16. Fit a new shaft. On no account straighten outt a

bend shaft.

Cause 17. Dismantle pump.

Cause 18. Check quiet running of pumps. Check coupling

alignment (when cold). Check oil quality and
cleanlines.

Cause 19. Fit new casing wearing rings, Check out-of-round

(true running of) rotor. Check presence of foreign
bodies in the pump (see also item 16).

Cause 20. Fit new impeller. Check suction head (cavitation).

Check system for presence of foreign bodies (see
also item 16).

Cause 21. Replace damaged components by new ones.

Cause 22. Replace damaged components by new ones.

Check shaft protection sleeves for true running
(out-of-round). Check suitability of packing material
used. Check that gland is not tightened askew and
observe rate of leakage.

Cause 23. Carefully repack stuffing box. Check suitability of

packing material used.

Cause 24. Realign coupling (when cold). Fit new bearings.

Check rotor for signs of damage.

Cause 25. Check suction pressure (cavitation). Check

coupling alignment. Check pump internals for
presence of foreign bodies.

Cause 26. Repack stuffing box. Tighten gland lightly only.

Alow slightly higher rate of gland leakage. Check
suitability of packing material used.

Cause 27. Check unobstructed flow through cooling liquid

feed line.

Cause 28. Fit an end ring or a new stuffing box gland. Check

condition of shaft protection sleeve.

Cause 29. Use treated cooling liquid. Fit filters in cooling liquid

lines.

Cause 30. Check rotor clearances. Check axial adjustment

(position) of rotor.

Cause 31. Check oil quality and quantity.

Cause 32. Check bearing components for signs of damage

and assemble them correctly.

Cause 33. Throughly clean bearings, bearing housings and

check condition of bearing of seal.

Cause 34. Remove all rus t from bearings and bearing

brackets. Change the oil fill.

Cause 35. Replace damaged components by new ones.

Check rotating components for out-of-round. Check
suitability of materials used. Make sure all seal
components seat accurately, and lookout for
leakage.

Cause 36. Carefully insert seal. Check materials for suitability.

Cause 37. Measure the seal anew. Refer to manufacturer.

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Cause 38. Check unobstructed flow through cooling liquid

supply line.

Cause 39. Fit a new bush or a spacer sleeve in the cooling

housing.

Cause 40. Use treated cooling liquid. Incorporate filters in

cooling liquid line.

Quantity for pump

construction with

14. Spare Parts

When ordering spare parts, always please quote the item
numbers, and designations of the items concerned, and the
Works serial number of the pump, in order to avoid any queries
and delays in delivery. The Works serial number of the pump
can be obtained from the title page of the present instruction
manual, or from the rating plate on the pump.

We recommend keeping the following spare parts in stock in
order to be in a position to remedy rapidly any operating trouble
which might arise.

Remark

Standard

Part No.

210 Shaft with keys 1 1 1 *)
230 Impeller S S S *)
320 Angular contact ball bearing 2 2 2 Only on heavy duty bearing bracket
321 Deep groove roller bearing 1 1 1
322 Cylindrical roller bearing 1 1 1

400.1 Flat gasket 1 1 1

400.2 Flat gasket S S S

400.3 Flat gasket 2 4 4

400.4 Flat gasket 2 2 2

400.5 Flat gasket 1 1 1 Only on heavy duty bearing bracket

400.6 Flat gasket - - 2

412.2 O-ring 1 1 1

412.3 O-ring 2 2 2 *)

412.4 O-ring - 2 2

412.7 O-ring 2 2 2 Only on heavy duty bearing bracket

422.1 Felt ring 3 3 3 Only on heavy duty bearing bracket

422.2 Felt ring 1 1 1 Only when bearing is sealed

461.1 Stuffing box packing (in metres) 2 2 ­472 Mechanical seal, complete - - 2
502 Casing wearing ring S S S
521 Stage sleeve S-1 S-1 S-1

523.1 Shaft protection sleeve - - 1 *)

524.1 Shaft protection sleeve 1 1 - *)

524.2 Shaft protection sleeve 1 1 - *)

525.1 Spacer sleeve 1 1 1 *)

525.2 Spacer sleeve 1 1 1 *)

540.1 Stage bush 1 1 1 Only on pump size 150

540.2 Stage bush 1 1 1 Only on material alternative chrome steel

540.3 Stage bush 1 1 1 Only on material alternative chrome steel
541 Stage bush S-1 S-1 S-1 Only on material alternative chrome steel

52.1 Adaptor sleeve, complete 1 1 1

stuffing box

Special stuffing

boxes HW

V, VSM, VSH

Mechanical seal

S = Number of stages
*) Parts for complete pump rotor.
The latter should be assembled and dynamically balanced, and kept in stock as a complete spare parts.

27

WK

15. Check List

15.1 Pre-requisites for Initial Commissioning

Check direction of rotation of driver with pump disconnected.
Check correct alignment of pumping set with appropriate
alignment jigs and dial micrometers.

Check that the stuffing box gland seats squarely and has
sufficient guidance (with the aid of a feeler gauge, check that
the gap between the shaft protection sleeve and the stuffing
box gland remains the same around the circumference). If
mechanical seals are fitted, check that the circulation lines are
vented at the apex.

Check that the system is primed with the fluid pumped, and
thoroughly vented via the vent valve in the discharge line (if
provided), and via the vent screws of the pressure gauge valve
(suction pressure-discharge pressure).

Check that the valves in the minimum flow line are opened.
Check that the valve in the manually-operated line of the
minimum flow device is opened.

Check that oil has been filled in the bearing bracket and that
the required oil level has been attained (by oil pouring out of
the overflow holes).

Observe the start-up procedure for the driver.

0

If the operating temperature exceed 150
valve in the cooling liquid supply line is fully open, and that the
fluid flows through freely, also check that the throttling valves
in the cooling liquid lines are fully open.

Check that the isolating valve in the suction head line is fully
open.

Check that the isolating valve in the discharge line is closed.

C, check that the main

15.4 Initial Operation with Hot Fluid

When the nominal temperature of the fluid pumped has been
attained, adjust the flow rate of the cooling liquid supply. This
should be done by throttling the individual valves in the internal
cooling liquid piping system in such a way that a temperature
differential of 10

0

C max. is set up between the cooling liquid

inlet and outlet.

During operation, check the pressure drop across the strainer
in the suction lift or suction head line. When the max.
permissible pressure drop value has been reached, switch off
the pumping set and clean the strainer.

15.5 Supervision of Operations & Maintenance

During operation, the pump should be kept under careful
observation. The following measurement values should be
checked at frequent intervals :

Suction pressure

Suction temperature

Pump discharge pressure

Temperature at pump discharge nozzle

Bearing temperature

Stuffing box leakage

Temperature of mechanical seals

Cooling liquid temperature at cooler outlet (Max. temperature
differential 10

0

C)

Check that the pump runs smoothly and quietly at all times,
and check the pressure drop across the suction head line by
differential pressure measurement.

15.2 Initial Start-up with Cold Water

Switch on driver for a short instant, and switch it off again
immediately. Check that rotor runs down smoothly and evenly
to a standstill.

Switch driver on again. Check quiet running of pump.

Observe the stuffing boxes (they should not run too hot).

Make sure that the pump runs smoothly and quietly, and that
the stuffing boxes function correctly.

On pumps fitted with mechanical seals, keep a check on the
temperature in the circulation lines.

Keep a check on the pressure gauge indications (suction and
discharge pressures).

If the pump is turbine driven, run up turbine to full operating
speed as rapidly as possible, and make sure the pump runs
quietly during this time.

15.3 Priming the Boiler

Crack the isolating valve in the discharge line open slowly
(remember lag of servo-actuated valves). Run the pump within
the confines of the limitation curve of the operating diagram
(see section 10.3 ‘‘Pump Operation and Supervision’’).

We recommend keeping a log book on pump operation, to
supervise the pumps more closely; the following data should
be entered in this log book at hourly intervals : rate of flow,
suction pressure, discharge pressure, temperature of fluid
pumped, rotational speed and axial rotor position. The times
of start-up and shutdown should also be recorded, so that the
total number of hours of operation of the feed pump can be
ascertained at any time.

The oil level and oil quality should be checked, respectively
tested, after the first 200 hours of operation. Thereafter, the oil
level and oil quality should be checked at least once a month.

28

WK

16. Sectional Drawings and List of Components

ç

903.1

920.4

350 920.2

361

903.4

321

902.1 400.3

720.3

903.2

ç

400.3

731.2

322

901.2

350

52-1

360

210

903.2

920.3

902.2

507

412.3 451

400.4

452

461.1

550

524.2

905

920.1

Qty. Part Designation
per No.
pump

1 106 Suction casing
1 107 Discharge casing
S-1 108 Stage casing
1 160 Cover 5)
2 165 Cooling cover
S-1 171.1 Diffuser
1 171.2 Last stage
1 (210) Shaft
S (230) Impeller
2 (320) Contract ball bearing 5)
1 (321) Deep groove ball bearing
1 (322) Cylindrical roller bearing
2 350 Bearing housing
1 350.2 Heavy bearing housing
1 360 Bearing cover
1 360.2 Bearing cover/End side5)
1 361 Bearing cover/End side
S-1 (400.2) Flat gasket
2 (400.3) Flat gasket
2 (400.4) Flat gasket
2 (400.5) Flat gasket 5)
2 (412.2) O-ring
2 (412.3) O-ring
2 (412.4) O-ring
2 (412.7) O-ring 5)
2 (422.1 Felt ring 2)

107

525.2

171.2

412.2

108

Qty. Part Designation
per No.
pump

1 (422.2) Felt ring 2)
2 451 Stuffing box housing
2 452 Stuffing box gland
2 458 Lantern ring
2 (461.1) Stuffing box packing
2 500.1 End ring 2)
1 500.2 End ring 2)
2 500.4 Ring
Sx2 (502) Casing wearing ring 1)
Sx2 503 Impeller wearing ring 1)
2 507 Splash ring
1 508 Guide bush
S-1 (521) Stage sleeve
1 (524.1) Shaft protection sleeve
1 (524.2) Shaft protection sleeve
1 (525.1) Spacer sleeve
1 (525.2) Spacer sleeve
1 525.43/.8 Spacer sleeve
1 525.5 Spacer sleeve
1 (540.2) 1) Bush
1 (540.3) 1) Bush
1 (541) 1) Stage bush
S-1 550 Washer
2 (52-1) Adaptor sleeve
16 636 Grease nipple
1 638 Constant level oiler
2
2
2 644 Lubricating ring 5)
1 680 Cover sheet

171.1
521

680

500.4

230

400.2

502

524.1

525.1

106

451

412.3

507

461.1

452

400.4

Basic construction WK 40 to 125

Qty. Part Designation
per No.
pump

2 720.3 Double nipple
2 731.2 Plug
8 901.2 Hex. bolt
4 901.3 Hex. bolt 5)
4 901.4 Hex. bolt
16 902.1 Stud
4 902.2 Stud
8 902.3 Stud
2 903.1 Plug
2 903.2 Plug
2 903.4 Plug
1 903.5 Plug
1 903.12 Plug
8 905 Tie rod
2 913 Vent plug
16 920.1 Hex. nut
16 920.2 Hex. nut
4 920.3 Hex. nut

920.4 Shaft nut
1 923 Shaft nut 5)
1 932 Circlip 3) 5)
2 7A Cooling liquid outlet

7E Cooling liquid inlet
10A Sealing liquid outlet
10 E Sealing liquid inlet
11 E Flushing liquid inlet
13 B Oil drain

( ) Recommended spare parts
S Number of stages

1) Material alternative with CA6NM (special chrome steel with emergency running characteristics, approximately 14% Cr)

2) For out door execution felt ring Part No. 422.1/2 or Oil seal 421.1/2.

3) WK 150

4) Only supplied in conjunction with Part No. 230 (Impeller)

5) For heavy duty bearing construction

29

WK

Construction with constant level oiler
and bearing housing seal

913

X

500.1

422.1

WK 150 bearing construction

903.12 361 543 920.4 321 525.4 350

Constant level oiler
(viewed from X)

638

350 322 360

Grease-lubricated
construcion

638

731.2

Hot water stuffing box
HW.

350

165

452

412.3

412.4

Construction with bearing
housing seal

422.2 500.2 932

7A/7E

400.3 4003

451

524.2
(524.1)

461.1

Front end Drive end

Bearing construction incorporatingheavy-duty bearing housing WK 40 to 150

901.3 361 913 350.2 412.7 507

903.5
(13B)

412.7 644

400.5 543 901.4
160

525.8

720.3
(8B)

644 360.2

210932508320320923

525.5

902.3

Construction with CA6NM material alternative

540.2
107

503

412.2

171.2
230

400.2
108

541

171.1

521

502

106

210

540.3

Special stuffing boxes

165

452

VSM

165

452

VSH

412.3

412.3

350

350

412.4

412.4

7A/7E

400.3 4003

461.1

10A/10E

400.3 4003

458

461.1

451

524.2
(524.1)

451

524.2
(524.1)

Impeller wear rings and bushes

11E

400.3 4003

525.1525.2

165

452

412.3

350

412.4

461.1

458

451

524.2
(524.1)

30

WK

Balancing Liquid Piping

1. Field of Application

Balancing liquid piping is a must for WL pumps. However
for WK/WKS pumps balancing liquid piping is required
whenever the discharge pressure exceeds 20 bar for sizes
40 to 65 and for sizes 80 to 150 when this pressure
exceeds 15 bars.

2. Requirement and Connection

In case of WK/WKS pumps, the balancing of major portion
of axial thrust is achieved by means of balancing liquid
holes provided on each stage impeller. With this, the
pressure equalization on either side of impeller is attained.
Due to this, a certain quantity of liquid being pumped flows
towards the pressure side, which ultimately enters the
balancing chamber, formed between the walls of stuffing
box housing and discharge casing. This balancing liquid
quantity has to be drawn off from the balancing chamber,
which otherwise will accumulate there only and hamper
the performance of the pump. For this purpose a pipe
line is provided, which connects this high pressure
chamber to the low pressure region of suction casing (fig.
A). By this the pressure relieving of the discharge side
stuffing box housing is also achieved.

In case of WL pumps, the balancing of major portion of
axial thrust is achieved by means of balancing device.

Pipe line size Valve Size Size of

Safety Valve

16 x 1.5 DN15

20 x 2 DN20 DN20 x 32

25 x 2 DN25

Accessory Purpose Pressure Rating

Pressure gauge Indication of 0-6, 0-10 kg/cm2

balancing line reading
pressure

Check Valve Restrication of PN 40

back flow of
balancing liquid

Globe Valve Isolation of PN 40

balancing piping
for the purpose
of maintenance

Safety Valve To safe guard the PN 40 x 10

balancing piping

Fig. A

Balancing piping

This also involves the flow of balancing liquid into the
balancing chamber, which again has to be drawn off. In
case of WL pumps, this piping is either connected back
to the suction casing (fig. A) or to the feed water tank (fig.
B) depending upon the temperature and differential head
of the pumping liquid.

3. Size

The tapping size provided on the balancing chamber of
discharge casing and the recommended pipe line sizes
are given in the following table :

Pump Size Tapping on Pipeline size

Balancing Chamber mm

40, 50, 65 R 3/8’’ 16 x 1.5

80, 100 R 3/4’’ 20 x 2

125, 150 R 1’’ 25 x 2

4. Accessories

Whenever the balancing liquid piping is connected back
to the suction casing, no accessories are required.

When this connection is given back to feed water tank
(fig. C) then the following accessories are necessary.

Balancing piping from balancing chamber to suction casing

Fig. B

Balancing liquid in the deareator

Balancing piping in the feed water tank.

The sizes of the valves are to be considered as the
corresponding size of the pipeline given in article 3 above.

31

Feed water tank

Globe valve

Check valve

WK

Fig. C

Pressure Gauge

Z = End of KSB Supply

Safety valve

5. Illustrations

i) Balancing liquid fed back to suction casing. Fig. A

ii) Balancing liquid fed back to feed water tank. Fig. B

iii) Arrangement of valves in balancing line. Fig. C

6. Precautionary Notes

i) Connection of balancing liquid piping whether to

suction casing or to the feed water tank is indicated
on the front page (Technical Data Sheet) of the order
acceptance. This is to be strictly adhered to.

ii) Size of the balancing liquid piping should be exactly

as given in article 3 above.

iii) Whenever the balancing liquid line is fed back to

feed water tank, and if more than one pumps are
operating in parallel, the individual balancing liquid
lines should be independently connected to the feed
water tank, without joining them together, or even
putting them into a common header.

iv) The globe valve in the balancing liquid line back to

feed water tank should always remain in fully open
condition, and on no account should it be closed even
by accident.

v) The piping for safety valve has to be branched prior

to the check valve, so that all the further piping is
safe guarded against the increase in pressure.

32

NOTES

WK

NOTES

WK

NOTES

WK

WK

Operating Instructions

WK

Manufactured in technical collaboration with KSB Aktiengesellschaft., Germany by :

PUMPS LIMITED

Works : Telephone No. Telefax

Pimpri - Irrigation and Process Division, [phone], 770990 [phone]

Chinchwad - Power Projects Division,

Coimbatore - Water Pumps & Valves Division, NSN Palayam Post, [phone] - 9, 892647 [phone]

Vambori - Foundry Division, Ahmednagar - 413 704 (02426) 72528, 34, 50 (02426) 72443
Sinnar - Water Pumps Division, (02551) 30252, 53, 30255, 30256 (02551) 30254

Regd. Office :

Mumbai - 126, Maker Chamber III, Nariman Point - 400 021 [phone] - 42 [phone]

Zonal Offices :

Mumbai - 126, Maker Chamber III, Nariman Point - 400 021 (022) 2854237 - 42 (022) 2873299
Calcutta - 30, Circus Avenue, 2nd Floor, 700 017 (033) 2470473, 2400117 - 8 (033) 2470588
NOIDA - KSB House, A-96, Sector IV, NOIDA (0118) 54091 - 93 (0118) 525627, 550567

Chennai - Guindy House, 2nd Floor, 95 Anna Salai, 600 032 [phone] - 2, 2300629 [phone]

Branch Offices :

! Ahmedabad - [phone], 7543427 ! Aurangabad - [phone] ! Bangalore - [phone], 3493925 ! Baroda - [phone], 333226 ! Bareilly - [phone]
! Bhubaneshwar - [phone] ! Chandigarh - [phone], 549021 ! Durgapur - [phone] ! Guwahati - [phone] ! Hubli - [phone]
! Indore - [phone], 529704 ! Jaipur - [phone], 381206 ! Jamshedpur - [phone], 433471 ! Kochi - [phone] ! Lucknow - [phone], 274492
! Nagpur - [phone] ! Pune - [phone], 5536347 ! Raipur - [phone] ! Secunderabad - [phone] ! Vijayawada - [phone], 433384

Service Stations :

Odhav - Shed 22, G.V.M. Estate, Amedabad 382 410 (079) 2870372
NOIDA - A - 96, Sector IV, 201 301 (0118) 91 - 525626, 550567
Howrah - 142, Foreshore Road, Ramkrishnapur [phone]

Mumbai-Pune Road, Pune - 411 018

D-II Block, MIDC, Pune - 411 019 [phone], 774213, 774389 [phone]

151, Mettupalayam Road - 641 031

Plot No. E - 3, MIDC Sinnar, Malegaon, Dist. Nashik - 422 103

Dist. Gautam Budh Nagar, 201 301

Technical matter subject to change without notice.

Operating Instructions

0011.81 / 00 - 18 G3

WK

High Pressure Centrifugal Pumps

Works Order No. : ________________________________________________

Pump Type & Size : ________________________________________________

These operating instructions contain fundamental
information and precautionary notes. Please read the

manual thoroughly prior to installation of unit, electrical
connection and commissioning.
It is imperative to comply with all other operating instructions
referring to components of individuals units.