IMO D4 Maintenance And Service Instructions

Screw pumps

Maintenance and Service
Instruction

D4 0617GB

December 2000

This instruction is valid for all D4 pump models shown on page 2
Contents Page

List of components 2
Exploded view 3
Ordering code/Service intervals 4
Inspection of rotors/Sectional view 5
List of tools/Inspection of shaft seal 6
Dismantling/Reassembly 7
Pressure relief valve 11

D4 1 © IMO AB

A Member of the
COLFAX PUMP GROUP

D4

2

D4 0617GB
December 2000

Before commencing any work, read this instruction carefully!
Failure to comply with these instructions may cause damage and personal injury!

!

For more information about the pumps identification code, technical data and performance we refer to the
D4 Product description.
For more information about the pumps installation, start-up and trouble shooting we refer to the IMO
Installation and Start-up instruction for medium and high pressure pumps.

List of components

Valid for all D4 pumps in sizes: D4 025/032/038/045/052/060/070; Rotor diameter and Generation: L2/K2/N2
With version codes: The version code is composed of the letters in

the 4 columns. Also valid for pump options A101.

Example of pump designations std: D4 025L2 LRBE
option: D4 038 K2 LVBP A 101

Pos No Denomination Qty G011 G012 G050 G057 P.E. Note

101 Power rotor (CCW-rot.) 1 x (x)
102 Power rotor (CW-rot.) 1 x x
113 Key 1 x x x
1030 Valve 1 x x x
124 Retaining ring 1 x 13
124A Support ring 1 x 13
124B Washer 1 x 13
139 Balancing washer 1
139A Retaining ring 1 x 13
201 Idler rotor (CCW-rot.) 2 x (x)
202 Idler rotor (CW-rot.) 2 x x
376 Balancing bush 2 x x x
382 Screw 4 7
391 Plate 1 7
395 Support plate 1 x
395A Screw 2 x
401 Pump body 1 x
423 O-ring 1 10
427 Split flange 2 10
427A Weld stud 1 10
428 Screw 4 10
428A Washer 4 10
451 Screw 4 x
451A Washer 4 x
453 Screw 4 9
453A Washer 4 9
455 Screw 4 2
463 Plug 1 x 5
463A Washer 1 x x 5
489 Strainer 1 8
491 Nut 1 1
497 Valve seat 1 11
497A O-ring 1 11
501 Front cover 1 x
506 O-ring 1 x x
507 Washer 1 x
509 Shaft seal 1 x x
520 Cover 1 x
520A O-ring 1 x x
521 Screw 3 x
521A Washer 3 x
551, 5510 Inlet chamber 1 9
556 Gasket 1 x 9
557 Plug 1 11
601 Valve cover 1 11
602 Washer 1 11

LIR

V
T

B

J

T

E
P

Explanations:

G011 = Rotor set,
CCW-rotation

G012 = Rotor set
CW-rotation (std)

G050 = Shaft seal
G057 = Joint kit
P.E. = Pump

element G102
(CW) or G101
(CCW)

3

D4 0617GB

December 2000

Exploded view

Fig. 1

Pos No Denomination Qty G011 G012 G050 G057 P.E. Note

605 O-ring 1 11
608 Valve spindle 1 6
608A Retaining ring 1 3
608B Valve spindle 1 4
608C Nut 1 4
608D Pin 1 4
609 Washer 1 2
609A Screw 2 2
611 Washer 1 2
612 Regulating nut 1 12
614 Valve piston 1 11
615 Spring 1 11

Note 1 Valid for sizes 025-060 xxJE

2 Only for xxBP size 060-070
3 Only for xxBP size 025-032
4 Only for xxBP size 038-052

5 Not for xxBP
6 Valid for xxBP size 025-032, 060-070
7 Valid for xxTE
8 Valid for xxTE, xxJE
9 Not for xxTE

10 Valid for xxJE
11 Valid for xxBP
12 Valid for xxBP sizes 025-052
13 Valid for sizes 025

xxJE

xxBE

xxTE

xxBP

025-032

038-052

060-070

520

520A

507

509

521
521A

506

463
463A
401

113
102

202

376

501

1030

451
451A

395
395A

556

551

427
428A

428

491
489

453A
453

427

427A

423

556
551

453A
453

489

556

391
382

614
615

611
602
601
455
608
605
609
609A

497A
497

453A
453

557

614
615
612
608

605
602
601
608A

5510

614

615
612
608B
605
602
601

608C
608D

4

D4 0617GB
December 2000

Service intervals

The intervals for inspection and replacement of wear
parts vary greatly with the properties of the pumped
liquid and can only be determined by experience.
All internal parts of the D4-pump are lubricated by
the pumped liquid. Pumping a liquid containing
abrasive materials, or a liquid that is corrosive, will
significantly reduce service life and call for shorter
service intervals. Wear in the pump may be indi­cated by:

• Vibration

• Noise

• Loss of capacity

• Reduction in flow or pressure

• Leakage
In installations where unplanned shut downs must

be avoided, it is advisable to have a complete pump
available for replacement, should any malfunction
occur. Furthermore we recommend planned inspec­tion and overhaul at regular intervals, not exceeding
3 years.
It is recommended always to have the spares in­cluded in the minor spare part kit available.

If the pumps operating temperature exceeds
60°C let the pump cool off before any
service, maintenance or dismantling work is
commenced to avoid burn injury.

All work carried out on the pump has to be
performed in such a manner that risks for
personal injury are observed!

When handling liquids that may harm skin
use gloves and/or protective clothing.

When handling liquids which may involve
fire hazards appropriate precautions to
avoid danger are to be taken.

In case of failure for a system with elevated
pressure, fluid jets may cause injury and/or
damage.

Oil leakage may make the floor slippery
and cause personal injury.

!

!

!

!

!

!

!

Before any maintenance work, ensure that
the driver is deenergized and the pump
hydraulically isolated.

Connecting and disconnecting of electric
cables must be done only by personnel
authorized to do such work.

Recommendation for maintenance

Every shut down for service of a plant is costly. The
time for repair should therefore be limited to a
minimum which can be accomplished by keeping a
spare pump. The changed pump can later be re­paired at a suitable place and can then be used as a
spare pump.
For maintenance the following spare parts kits are
recommended:

Pos Part numbers, sizes
no Spare part sets 025 032 038 045 052 060 070

G011 Rotor set (CCW-rot.) Contact IMO AB
G012 Rotor set N-lead 163410 150425 163428 166926 150433 186569 186585

(CW-rot.) K-lead – – 146332 154534 186551 186577 186593
" L-lead 186544 156117 – – – – –

G050 Shaft seal xRxx 128314 128314 120873 124610 124610 128728 128728

xVxx 143859 143859 190336 190338 190338 142299 142299
xTxx 168906 168906 172726 172049 170449 168914 168914

G057 Joint kit xxxE 185819 185827 185835 185843 185850 185868 185876

Major kit (pump element)
different versions Contact IMO AB

Ordering code

Kit Contents To be used for

G057 Gaskets, O-rings, etc Dismantling of the

pump.

G053 Minor kit Normal scheduled

G057+shaft seal G050 inspection.

G054 Major kit, pump element Repair after

G102 (CW) or G101 (CCW) damage or greater

wear.

Ordering For IMO pump D4
example: 025N2 LVBE
Rotor set G012 Part no. 163410
Shaft seal G050 Part no. 143859

5

D4 0617GB

December 2000

Sectional view

521
520A
521A
509

520
507
451
501

451A 376 463

463A

1002 (102) (202) 395A 395

1030

(139) 506

602
609A

453
453A
5510
557

497A 556 (497) 614 615 611 608 605 455 609

556

453
453A

551

489 382 391

391

453
453A

551
423
427A

427
428

428A
491

489

xxBE

size 025

xxTE

xxJE

602
601

608C
608D
608B

453
453A
5510
557
615
612

497A 556 (497) 614 608 605 608A

124

124A

124B

(139A)

Fig. 2

Inspection of rotors

If the pump is not able to maintain the pressure
inspect the rotor parts by following the instructions
in fig. 10-11.
Internal clearances in the pump, which are vital for
its proper function, may have been affected by wear.
Acceptable wear can be determined only by experi­ence of the actual application. As a rule of thumb the
following max clearance values may apply:

• Between rotor and bores or bushings: 0.2 mm

• Between rotor flanks: 0.2 mm
For light duties (low pressure, medium viscosity)
even bigger clearances may be acceptable whilst for
low visc. /high pressure duties the limit will be
lower. Also check if there are major scratches on
these parts. If you find any of these problems,
replace the whole pump element, otherwise reas­semble the pump by following the instructions in
fig. 12 and forward.

xxBP size 060-070

xxBP size 025-032 xxBP size 038, 045, 052

6

D4 0617GB
December 2000

GREASE

List of tools necessary for dismantling/reassembly

Fig. 3

Sliding Puller
calliper

Plastic
mallet

ACG7 © IMO AB

O-rings

All O-rings found to be hard or damaged shall be
replaced.

Inspection of shaft seal

As the seal faces of a mechanical shaft seal are
lubricated by the fluid, a certain leakage will
always be present. Up to ten drops per hour can be
considered as acceptable. An external visual
inspection of the pump is advisable at least every
two days to assure that the shaftseal is not leaking

too much. Excessively leaking shaft seals should be
changed without delay, as the leakage normally will
grow worse and cause additional damage.
Follow the instructions in the dismantling/reassembly
session.
When working with a shaft seal, cleanliness is of
utmost importance. Avoid touching the seal faces. If
necessary, the seal faces should be cleaned immedi­ately prior to assembly, using a dust free cloth and
clean solvent.
Never use grease on the seal faces.

D4 5 © IMO AB

Shaft seal – assembly drawing

520A S2 S1 S4 S5 507

521 521A

520

ATTENTION
Be careful to mount these parts in right

order and in right direction!
Look carefully at this drawing!

S1 Seat
S2 O-ring
S4 Seal ring
S5 Bellows unit

2 pcs of
screw­driver

Screw
spanner
14 mm

Allen keys
5 mm, 6 mm, 10 mm

Oil can Grease

Shaft seal

D4 4 © IMO AB

Fig. 4

7

D4 0617GB

December 2000

C. D.

Fig. 7 Fig. 8

S2

S1

D4 © IMO AB

520

501

• Remove the key 113.

• Remove the screws 521A.

• Use two screw drivers to carefully pull off
the seal cover 520.

• Remove the seal seat S1 and O-ring S2 from
the seal cover 520.

D4 10 © IMO AB

A. B.

Dismantling

Fig. 5 Fig. 6

• Note the axial position of the shaft coupling.

• Release the stop screw.

• Remove the shaft coupling with a puller.

D4 7 © IMO AB

• Turn the electricity OFF.

• Close the valves.

• Remove the pump from the system.

ATTENTION
Use appropriate vessels to collect oil spill-

age when removing and opening the pump.

521A

113

520

ATTENTION
Protect the face of S1.

8

D4 0617GB
December 2000

D4 11 © IMO AB

S5

• Remove the screws 451 and washers 451A.

• Carefully loosen the front cover 501 from the
pump body 401 with a plastic mallet.

• Remove the front cover 501 and rotor set in
one move.

• Remove the shaft seal bellows unit S5 and
the seal ring S4.

E.

F.

ATTENTION
Protect the face of S4.

S4

451A

451

401

501

Fig. 10

Fig. 9

D4 13 IMO AB

202

D4 14 © IMO AB

• Separate the front cover 501 and the power
rotor 102.

• Inspect the rotors, balancing bushes 376 and
O-ring 506 by separating them.

G.

H.

ATTENTION
Be careful not to make scratches in the

surfaces of the balancing piston bore.

506

501

102

Fig. 12Fig. 11

376

102

202

202

D4 12 © IMO AB

9

D4 0617GB

December 2000

A.

C.

Fig. 14 Fig. 15

Reassembly

D4 19 © IMO AB

• Fit the O-ring 506.

• Lubricate it with bearing grease if it is
difficult to keep it in place.

D4 17 © IMO AB

506

• A nick has been filed on the power rotor
thread on the outer diameter at the discharge
end. This marked power rotor thread should
be fitted into the female thread on the idler
rotors marked in the same manner.

• Fit the power rotor 102 in the front cover 501.
(See fig. 12).

• Lubricate the rotor set.

• Assemble it including balancing bushes 376.

D4 20 © IMO AB

• Carefully insert the rotor set into the pump
body 401.

• Watch the position of O-ring 506.

• Make sure the bolt holes match.

• Fit the screws 451 and the washers 451A.
Tight the screws crosswise.

D4 18 © IM O AB

D.

Fig. 16 Fig. 17

E.

376

501

102

451A

451

401

501

506

Fig. 13

B.

• Check prior to assembly – by mounting the
balancing bushes (376) in the pump body
(401) and by placing a ruler over their end
faces – that the balancing bushes extend
0,0 - 0,25 mm above the end face on the pump
body. If not, replace the balancing bushes.

0,0-0,25 mm

10

D4 0617GB
December 2000

H. I.

113

D4 23 © IMO AB

Fig. 21

Fig. 20

• Lubricate and fit the O-ring 520A on the seal
cover 520. Fit the seal cover onto the power
rotor shaft 102.

• Fit the screws 521 and tighten them carefully.

• Fit the shaft key 113.

• Fit the coupling half back into place and
lock with locking screw.

• Check that the axial position is the same
as before dismantling. (See fig. 6).

• Put the pump back into the system and
proceed according to instructions under
”Start-up” in the installation manual.

S4

D4 22 © IMO AB

• Fit the O-ring S2 in the seal seat S1.

• Fit the seat S1 in the seal cover 520.

• Lubricate the power rotor shaft, the bellows
unit S5 and the seal ring S4.

• Fit the bellows unit S5 into the front cover

501.

• Fit the seal ring S4. Note the position of the
drive notches on S4 and S5. They need to fit
together.

D4 21 © IMO AB

Fig. 18 Fig. 19

F. G.

S5

501

S2

520

S1

521

520

520A

102

ATTENTION
Do not use dirty fingers on the seal face.

Keep it clean and dry.

11

D4 0617GB

December 2000

Fig. 22

Pressure relief valve D4xxBP

D4 24 © IMO AB

xxBP

025-032

038-052

060-070

614
615

611
602
601
455
608
605
609
609A

614
615
612
608

605
602
601
608A

5510

614

615
612
608B
605
602
601

608C
608D

Dismantle

• Remove the valve unit from the pump.

• Release spring force by turning the spindle
CCW.

025-052

- Loosen cover 601 and remove it together
with the nut by using the valve spindle.

- Remove retainer 608A or C.

- Pull out the valve spindle (608 or 608B) and
replace the O-ring (605).

060-070

- Remove cover (601) by removing screws
(455) and remove spring washer (611).

- Remove screw (609A) and washer 609.

- Unwind the spindle (608). Replace the
O-ring (605).

• Remove spring (615) and valve piston (614).

• Replace valve piston if it is damaged.

• If the valve seat is damaged the whole inlet
chamber (5510) has to be replaced.

• Reassemble in reversed order.