Circor IMO CIG User manual

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PRODUCT SERVICE MANUAL
FOR
CIG Lip Seal Double Pumps
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WARNING 
The Imo General Installation Operation, Maintenance, and
Troubleshooting Manual, (No. SRM00046), as well as all other component
manuals supplied with these type units should be read thoroughly prior
to pump installation, start-up, operation, maintenance or troubleshootin
g
.
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SRM00049 REV. 04 (20-0051) February 2020
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READ THIS ENTIRE PAGE BEFORE PROCEEDING
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FOR THE SAFETY OF PERSONNEL AND TO PREVENT DAMAGE TO THE EQUIP-
MENT, THE FOLLOWING NOMENCLATURE HAS BEEN USED IN THIS MANUAL:
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D A N G E R
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Failure to observe the precautions noted in this box can result in severe bodily
injury or loss of life.
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W A R N I N G
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Failure to observe the precautions noted in this box can cause injury to
personnel by accidental contact with the equipment or liquids. Protection
should be provided by the user to prevent accidental contact.
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CAUTION ATTENTION 
Failure to observe the precautions noted in this box can cause damage or
failure of the equipment.
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Non-compliance of safety in-
structions identified by the fol-
lowing symbol could affect
safety for persons:
Safety instructions
where electrical safety
is involved are identi-
fied by:
Safety instructions which shall be
considered for reasons of safe
operation of the pump and/or pro-
tection of the pump itself are
marked by the sign:
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ATTENTION
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CONTENTS
SAFETY AND TABLE OF CONTENTS ................................................................................................ A
A. GENERAL INSTRUCTIONS .................................................................................................... 1
B. INTRODUCTION ..................................................................................................................... 1
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C. DESCRIPTION OF EQUIPMENT ............................................................................................ 1
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D. PUMP MODEL IDENTIFICATION ........................................................................................... 2
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E. ORDERING INSTRUCTIONS ................................................................................................... 3
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F. OPERATION .............................................................................................................................. 3
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G. PUMP DISASSEMBLY PROCEDURES .................................................................................. 3-5
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H. INSPECTION OF PARTS ........................................................................................................ 6-7
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I. MACHINING INSTRUCTIONS ................................................................................................ 7
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J. SPARE PARTS AND KITS ....................................................................................................... 9
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K. PUMP REASSEMBLY PROCEDURES ................................................................................... 10-14
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L. TROUBLESHOOTING ....................................................................................................................................................... 14
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ATTENTION
If operation of this pump is critical to your business, we strongly recommend you
keep a spare pump or major repair kit in stock at all times. As a minimum, a minor
repair kit (O-rings, gaskets, shaft seal and bearings) should be kept in stock so
pump
refurbishment after internal inspection can be accomplished.

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A. GENERAL INSTRUCTIONS
The instructions found herein cover the disassembly, assembly and parts identification of CIG double pumps
with lip seals.
NOTE: Individual contracts may have specific provisions that vary from this manual. Should any questions arise
which may not be answered by these instructions, refer to the General Instructions Manual, CA-1, provided
with your order. For further detailed information and technical assistance please refer to Imo Pump,
Technical/Customer Service Department, at [phone].
This manual cannot possibly cover every situation connected with the installation, operation, inspection, and
maintenance of the equipment supplied. Every effort was made to prepare the text of the manual so that engineering
and design data is transformed into the most understandable wording. Imo Pump must assume the personnel assigned
to operate and maintain the supplied equipment and apply this instruction manual have sufficient technical knowledge
and are experienced to apply sound safety and operational practices which may not be otherwise covered by this
manual.
In applications where equipment furnished by Imo Pump is to become part of processing machinery, these instructions
should be thoroughly reviewed to ensure proper fit of said equipment into overall plant operational procedures.
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WARNING 
If installation, operation, and maintenance instructions are not correctly and strictly followed and
observed, injury to personnel or serious damage to pump could result. Imo Pump cannot accept
responsibilityforunsatisfactoryperformanceordamageresultingfromfailure to comply with instructions.
B. INTRODUCTION
This instruction manual covers CIG double pumps with lip seals. This series of pumps has been designed for use
in hydraulic, lubricating seal and fuel oil applications. The model and design construction of each pump can be
identified by the designator code on the pump nameplate. Definitions of model designators are identified in Figure 1.
C. DESCRIPTION OF EQUIPMENT
The CIG double pumps with lip seals are positive displacement, internal gear pumps consisting of a single shaft
that runs through the center of pump housings. This shaft drives the external gears (pinion gears) which in turn
drives the internal gears (ring gears). Fluid is carried between the internal and external gear teeth of each pump
and is discharged as the teeth mesh. The pinion and ring gears are separated in each pump by a crescent which
is a sealing element in the pump between inlet and discharge ports.

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D. PUMP MODEL IDENTIFICATION
This instruction manual covers the Imo CIG double pumps with lip seals.
Themodelofeachpumpisidentifiedonthepump nameplate.
Refer to Figure1 forinstructional keyswhenusingthis manual.
Double Pump Model Key
CIG 52 050/33 012 RL I/D/E P/W
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Series
Front Pump Frame Size
(2, 3, 4, 5, 6, 8)
Pressure Rating
1 = Single Stage (Low Pressure)
2 = Single Stage (High Pressure)
3 = 2 Stages
4 = 3 Stages
Nominal Displacement
In CM3/Rev.
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Back Pump Frame Size
(2, 3, 4, 5, 6, 8)
P – Petroleum Base Fluids (Standard)
W – Low Viscosity Fluids Modification
I – Internal Drain Standard)
D – External Drain For High Suction Pressure
E – External Drain For Low Viscosity
and Normal Suction Pressure
R – CW Rotation (Standard)
L – CCW Rotation
Nominal Displacement
In CM3/Rev.
Pressure Rating
1 = Single Stage (Low Pressure)
2 = Single Stage (High Pressure)
3 = 2 Stages
4 = 3 Stages
Figure 1 – Double Pump Configuration
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E. ORDERING NSTRUCTIONS
When corresponding with Imo Pump regarding CIG Single Series pumps, refer to the pump nameplate,
Instruction manual and the assembly drawing as instructed below:
1. From pump nameplate, record the pump model number. Also record the manufactured lot number
and date (these are stamped on the housing near the nameplate).
2. Record instruction manual number, revision and date.
3. From the instruction manual, record the figure numbers that apply to the replacement part(s).
4. From the assembly drawing or instruction manual (see Table 1, Pump Parts List) provide the IDP
Number(s) and names for the replacement parts(s).
5. Give the above information to your Imo Service Representative.
Imo sales and service representatives are listed herein and in Imo General Installation Operation, Maintenance,
and Troubleshooting Manual, (No. SRM0046).
F. OPERATION
LIQUID LIMITATIONS – Never operate with fluids that are corrosive to iron, steel, aluminum or bronze. The
pump is designed for fluids having the general characteristics of oil.
CAUTION ATTENTION 
Operating conditions, such as speed, fluid viscosity, temperature, inlet pressure, discharge
pressure, filtration, duty cycle, drive type, mounting, etc. are interrelated. Due to these variable
conditions, the specific application limits may be different from that of the operational limitations.
This equipment must not be operated without verification that operating requirements are within
its capabilities.
G. PUMP DISASSEMBLY
Refer To Assembly Drawing In Back Of Manual
1. Remove drive key (36).
2. Remove capscrews (38) and end cover (15) with O-ring (35).
3. Remove capscrews (17) and washers (18). (Washers not used on single stage units.)
CAUTION ATTENTION 
In next step, ring gear (20), pinion (19) and key (21) will be removed. If ring (20) and pinion (19)
are to be reused, identify them, with a marker or the like, so it can be determined to which housing
they belong (if there is more than one housing in pump) and which direction face of each gear
was positioned in housing. Do not mark with scribe or punch as this may leave a burr or high
spot which could lead to pump damage or seizure. If key (21) is to be reused, mark it so that it
can be assembled into its original stage and facing its original direction.
4. Remove square gear housing (7), ring gear (20), pinion gear (19) and key (21) from shaft (6). Do not permit
dowel pin (22) to drop as housing (7) is removed. Remove dowel pin (22) from either square housing (7),
intermediate flange (5) or back of round housing (14) whichever is applicable.
NOTE: If square gear housing (7) will not slide easily off shaft (6), and rear pump is a one stage unit, clamp pump in
a vise with square housing (7) free. Position a wedging device between the square housing (7) and
intermediate flange (5). Pry gap until the square housing (7) if free to slide off shaft (6). If pump has more
than one stage, clamp round housing (14) in a vise with square housing (7) free. With a soft-headed
hammer, tap alternately on corners of square housing (7) until there is sufficient gap between square
housing (7) and back of round housing (14) to insert a wedging device. Pry the gap until square housing (7)
is free to slide off shaft.

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CAUTION ATTENTION 
Take care not to damage either faces that are being pried against or 0-ring (10) with prying
device.
CAUTION ATTENTION 
If gear housing (007) will not slide off easily because its bushing (54) was seized on shaft
(006), ball bearing (031) was most likely damaged when housing (7) was pried off and must
be replaced. On the other hand, if gear housing (7) will not slide off easily because its rabbet
was jammed in housing tube (23) or intermediate cover (5) counter bore, whichever is
applicable, ball bearing (31) may not have to be replaced.
NOTE: If housing (7), ring gear (12) or pinion gear (11) cannot be removed without applying excessive force, unit
should be returned to Imo for further disassembly and inspection.
5. If rear pump has only one stage, proceed to step #9. If pump has more than one stage, continue with step #6.
6. Remove housing tube (23). Remove O-rings (10) from rabbets on square housing (7) and round housing (14).
NOTE: Neither housing tube (23) nor O-ring (10) need be removed from round housing (14) unless O-ring (10) is
to be replaced. (Replacing O-rings is good practice when a pump is disassembled after extended
service or if damaged during disassembly.
CAUTION ATTENTION 
In next step, ring gear (20), pinion (19) and key (21) will be removed. If ring (20) and pinion
(19) are to be reused, identify them, with a marker or the like, so it can be determined to
which housing they belong (if there is more than one housing in pump) and which direction
face of each gear was positioned in housing. Do not mark with scribe or punch as this may
leave a burr or high spot which could lead to pump damage or seizure. If key (21) is to be
reused, mark it so that it can be assembled into its original stage and facing its original
7. Remove round gear housing (14), ring gear (20) pinion gear (19) and key (21) from shaft (6). Do not permit dowel pin
(22) to drop as gear housing (14) is removed. Remove dowel pin (22) from either next round gear housing (14) or
intermediate flange (5), whichever is applicable.
NOTE: If round gear housing (14) will not slide off easily shaft (6), and this is the last round housing (14) to be
removed, clamp it in a vise with intermediate flange free (5). With a soft headed hammer, tap alternately on
corners of intermediate flange (5) to separate it from round housing (14). When there is sufficient gap
between intermediate flange (5) and round housing (14), insert wedging device. Pry gap until round
housing (14) is free to slide off shaft (6). If there are several round housings (14) to remove, clamp pump in
a vise with rearmost round housing (14) free. Position a wedging device between the round housings (14).
Pry gap until rearmost round housing (14) is free to slide off shaft (6).
CAUTION 
A
TTENTION 
Take care not to damage either faces that are being pried against or 0-ring (010) with prying
device.
NOTE: If gear housing (14) will not slide off easily because its bushing (53) was seized on shaft (6), ball bearing
(31) was most likely damaged when housing (14) was pried off and must be replaced. On the other hand, if
gear housing (14) will not slide off easily because its rabbit was jammed in housing tube (23) or
intermediate flange (5) counterbore, whichever is applicable, ball bearing (31) may not have to be
replaced.
NOTE: If housing (14), ring gear (20) or pinion gear (19) can not be removed without applying excessive force,
unit should be returned to Imo for further disassembly and inspection.
8. Repeat steps 6 & 7 until all round housings (14) are removed.
9. Remove O-ring (10) from intermediate flange (5) if it did not come off with last housing removed.
10. Remove capscrews (39) and washers (34). (Washers not used on single stage units.)

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11. Remove intermediate flange (5) from shaft (6). Do not permit dowel pin (37) to drop as intermediate flange (5)
is removed. Remove dowel pin (37) from either round housing (3), or square of housing (4) whichever is
applicable.
NOTE: If intermediate flange (5) will not slide easily off shaft (6) and front pump has more than one stage, clamp
rest of pump in a vise with intermediate flange (5) free. With a soft-headed hammer, tap alternately on
corners of intermediate flange (5) until there is sufficient gap to insert a wedging device between it and
front pump round (3) or square (4) housing, whichever is applicable. If front pump is a single stage pump,
insert prying device between intermediate flange (5) and square housing (4) and pry apart.
CAUTION ATTENTION 
Take care not to damage either faces that are being pried against or 0-ring (10) with
prying device.
CAUTION ATTENTION 
If intermediate flange (5) will not slide off easily because its sleeve bushing (54) was
seized on shaft (6), ball bearing (31) was most likely damaged and must be replaced.
12. If front pump has only one stage, proceed to step #17. If pump has more than one stage, continue with step #13.
CAUTION ATTENTION 
In next step, ring gear (12), pinion (11) and key (13) will be removed. If ring (12)
and pinion (11) are to be reused, identify them, with a marker or the like, so it can
be determined to which housing they belong (if there is more than one housing in
pump) and which direction face of each gear was positioned in housing. Do not mark
with scribe or punch as this may leave a burr or high spot which could lead to
pump damage or seizure. If key (13) is to be reused, mark it so that it can be
assembled into its original stage and facing its original direction.
13. Remove pinion gear (11) and key from shaft (6) and ring gear (12) from front pump round housing (3).
NOTE: If pinion gear (11) will not slide easily off shaft (6), its key (13) is most likely at least partially sheared.
In this case, the disassembly cannot be completed in the field without the chance of damaging other
good parts and the unit should be returned to Imo for further disassembly and inspection.
NOTE: If ring gear (12) will not come out of round housing (3), it is most likely seized on its OD and will not be
possible to remove. The pump can still be disassembled with the ring gear (12) in the housing (3).
14. Remove round housing (3) from shaft (6). Do not permit dowel pin (37) to drop as round housing (3) is removed.
Remove dowel pin (37) from either round housing (3), or square housing (4) whichever is applicable.
NOTE: If round gear housing (3) will not slide easily off shaft (6), clamp it in a vice with the rest of the pump free.
With a soft-headed hammer, tap on gear end of shaft (6) until there is sufficient gap to insert a wedging
device between the round housing (3) and the next round (3) or square (4) housing, whichever is
applicable. Pry the gap until round housing (3) is free to slide off shaft.
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CAUTION ATTENTION 
Take care not to damage either faces that are being pried against or 0-ring (10) with
prying device.
NOTE: If the shaft had to be hammered to remove the gear housing (3) from the shaft, the ball bearing (31) was
damaged and must be replaced.
NOTE: If housing (3) cannot be removed without applying excessive force, unit should be returned to Imo for
further disassembly and inspection.
15. Remove housing tube (8). Remove O-rings (41) from rabbets on square housing (4) or round housing (3)
whichever is applicable.

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NOTE: Neither housing tube (8) nor O-ring (41) need be removed from round housing (3) unless O-ring (41) is to
be replaced.
16. Repeat steps 13, 14 and 15 until all round housings (3) are removed.
CAUTION ATTENTION 
In next step, ring gear (12), pinion (11) and key (13) will be removed. If ring (12) and
pinion (11) are to be reused, identify them, with a marker or the like, so it can be
determined to which housing they belong (if there is more than one housing in
pump) and which direction face of each gear was positioned in housing. Do not mark
with scribe or punch as this may leave a burr or high spot which could lead to pump
damage or seizure. If key (13) is to be reused, mark it so that it can be assembled
into its original stage and facing its original direction.
17. Remove pinion gear (11) and key (13) from shaft (6) and ring gear (12) from front pump square housing (4).
NOTE: If pinion gear (11) will not slide easily off shaft (6), its key (13) is most likely at least partially sheared.
In this case the disassembly cannot be completed in the field without the change of damaging other
good parts and the unit should be returned to Imo for further disassembly and inspection.
18. Remove square housing (4) from shaft (6). Do not permit dowel pin (37) to drop as square housing (4) is removed.
Remove dowel pin (37) from either square housing (4) or front flange (2), whichever is applicable.
NOTE: If square gear housing (4) will not slide easily off shaft (6), clamp it in a vice with the front flange (2) free.
With a soft-headed hammer, tap on gear end of shaft (6) until there is sufficient gap to insert a wedging
device between the square housing (4) and the front flange (2). Pry the gap until square housing (4) is free
to slide off shaft (6).
CAUTION ATTENTION 
Take care not to damage either faces that are being pried against or 0-ring (10) with
prying device.
CAUTION ATTENTION 
If the shaft had to be hammered to remove the square gear housing (4) from the
shaft, the ball bearing (31) was damaged and must be replaced..
NOTE: If square housing (4) can not be removed without applying excessive force, unit should be returned toImo
for further disassembly and inspection.
19. Remove capscrews (42) from seal housing (9).
20. Remove shaft (6) from front flange (2). Removal of shaft also removes seal housing (9), outside lip seals (32), ball
bearing (31), and bearing retaining ring (33).
21. Remove seal housing (9), with lip seals (32), from shaft (6).
22. If lip seals (32) are to be replaced, remove them from seal housing (9) and discard.
23. If ball bearing (31) is to be replaced, remove snap ring (33) from shaft (6), press ball bearing (31) off shaft (6)
and discard.
24. If inside lip seal (51) is to be replaced remove and discard lip seal (51).
H. INSPECTION OF PARTS
1. BALL BEARING – Ball bearings should be free turning and quiet. Their grease should have a soft
consistency and not look or smell burned.

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2. GEAR FACES – Some light scratching is acceptable, but if there is any scoring, the part should be replaced.
These faces cannot be ground to remove a heavy score mark because their width is critical to performance of pump.
Grinding more than several ten thousandths of an inch will cause low capacity. If the face is not flat, pump seizure
could occur.
NOTE: Rework other than light stoning or cleaning of gears or gear housings is not recommended. New gear
housings are provided with sleeve bearing factory installed.
3. RING GEAR OD – Light scratching and polishing is acceptable. If scoring is present, ring gear should be replaced.
4. HOUSING
a. Faces – Some light scratching is acceptable, but if there is any scoring, the part should be replaced.
b. Crescent –This piece should be checkedfor gouges or scoring. If the marking is severe, housing should be
replaced.
c. ID – If any scoring is present, housing should be replaced.
5. SHAFT – Check shaft for wear, particularlyareas where lip seals and bushings are located when pump is
assembled.Any heavy wear is cause for shaft replacement. Check edges of keyways for cracks, chipping or
rounding. If any of these exists, shaft should be replaced.
6. SLEEVE BEARING – If scoring or heavy polishing is present, bearing must be pressed out of housing and replaced.
7. FRONT AND INTERMEDIATE COVERS – If faces are scored or heavily scratched, they must be machined
per machining instructions. Check ball bearing seating area in front cover after severe ball bearing failure. If ball
bearing seating OD is badly scored, deburr it before pump assembly.
8. LIP SEAL – If seal edge is flat or damaged or elastomer is deteriorated, replace lip seals.
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I. MACHINING INSTRUCTIONS
The front cover (001) and intermediate flange (005) can usually be restored to as-new condition by machining
damaged faces. Sleeve bushings (054) usually require replacement when cover is machined. To repair damage
to face of front cover (Figure 2) and to replace sleeve bushings (C) proceed as follows:
1. Press out and replace bushings (C) in front cover, ensuring that slit is positioned as shown.
NOTE: If pump is equipped with bronze bearing, consult factory.
2. Fabricate a bushing sizing tool as shown in Figure 3. Press sizing tool through bushing from same direction
bushing was originally installed to properly size bushing bore.
3. Place front cover in a lathe and indicate face (A) and counterbore (B) square and concentric with respect to
bore(C) within .0008 inch TIR.
4. Machine face (A) deep enough to remove any scored material. Ensure that face is flat within .0008 inch TIR with
a 32 microinch finish.
CAUTION ATTENTION
Being out of flat in excess of .008" can cause pump failure.
NOTE: If more than .015" is machined (removed) from face (A, Figure 2), the same amount should be
machined (removed) from G and F.

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Figure 2 – Front Cover
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Figure 3 – Sleeve Bearing (053), (054) Sizing Tool