Circor IMO G12D S-137 Series User manual

1
PRODUCT SERVICE MANUAL
FOR
_G12D_ _(S)-137 and 350 PUMPS
WARNING
This Instruction Manual and General Instructions Manual, SRM00046, should be
read thoroughly prior to pump installation, operation or maintenance.
Manual No. SRM00125 Rev. 01 (20-0051) JULY, 2020

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READ THIS ENTIRE PAGE BEFORE PROCEEDING
FOR SAFETY OF PERSONNEL AND TO PREVENT DAMAGE TO EQUIPMENT, THE FOLLOWING
NOMENCLATURE HAS BEEN USED IN THIS MANUAL:
DANGER
Failure to observe precautions noted in this box can result in severe bodily injury
or loss of life.
WARNING
Failure to observe precautions noted in this box can cause injury to personnel by
accidental contact with equipment or liquids. Protection should be provided by
user to prevent accidental contact.
CAUTION ATTENTION
Failure to observe precautions noted in this box can cause damage or failure of
equipment.
Non compliance of safety
instructions identified by
the following symbol
could affect safety for
persons:
Safety instructions where
electrical safety is
involved are identified by:
Safety instructions which
shall be considered for
reasons of safe operation
of pump and/or protection
of pump itself are marked
by the sign:
ATTENTION
ATTENTION
If operation of 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.
CONTENTS
Safety and Table of Contents........................................................................................................2
A. General Instructions ................................................................................................................3
B. Introduction..............................................................................................................................3
C. Description of Equipment ........................................................................................................3
D. Pump Model Identification .......................................................................................................4
E. Ordering Instructions ...............................................................................................................4
F. Operation ................................................................................................................................5
G. Parts List..................................................................................................................................6
H. Pump Maintenance and Seal Drawing ....................................................................................7
I. Troubleshooting.....................................................................................................................11
J. Field and Factory Service and Parts .....................................................................................11
K. Assembly Drawings ......................................................................................................... 12-14
L. Mechanical Seal Drawings ....................................................................................................14

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A. GENERAL INSTRUCTIONS
The instructions found herein cover the disassembly, assembly and parts identification of _G12D_-137
and 350 pumps.
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, SRM00046, 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 equipment supplied. Every effort was made to prepare text of manual so that engineering
and design data is transformed into the most easily understood wording. Imo Pump must assume personnel
assigned to operate and maintain 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.
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 responsibility for unsatisfactory performance or
damage resulting from failure to comply with instructions.
B. INTRODUCTION
This instruction manual covers series _G12D_-137 and 350 Imo pumps. This series of pumps has been
designed for use in hydraulic, lubricating, seal, distillate, residual, fuel and crude 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
_G12D_-137 and 350 series pumps are positive displacement, rotary screw pumps consisting of
precision bored housings which enclose a driven screw (power rotor) and intermeshing following screws
(idler rotors). These screws when rotating form a succession of closures or cavities. As they rotate, fluid
is moved axially from inlet port to outlet port in a continuous, uniform flow with minimum fluid pulsation
and pump noise.
D. PUMP MODEL IDENTIFICATION
This instruction manual covers Imo Series _G12D_-137 and 350 pumps. The model of each pump is
identified on pump nameplate. Refer to figure 1 and table 1 for instructional keys when using this
manual.

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Figure 1 – Model Designator Definitions
E. ORDERING INSTRUCTIONS
When corresponding with Imo Pump regarding Series _G12D_-137 and 350 pumps, refer to pump
nameplate, this instruction manual, and assembly drawing as instructed below:
1. From pump nameplate, record pump model number, serial number, and manufactured date.
2. Record instruction manual number, revision, and date.
3. From instruction manual, record figure numbers that apply to replacement part(s).
4. From assembly drawing or parts list (see table 2) provide IDP number(s) and names for replacement
part(s).
5. Give above information to your Imo service representative.
Imo sales and service representatives are listed herein and in General Instruction Manual, SRM00046.
F. OPERATION
F.1 LIQUID LIMITATIONS
CAUTION ATTENTION
Never operate with water. Pump is designed for liquids having general characteristics of oil.

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F.2 OPERATING LIMITS
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, specific application limits may be different from operational limitations.
Equipment must not be operated without verifying system operating requirements are within
pump’s capabilities.
Under no circumstances are the following operating limits (specified in table 1) to be exceeded
without specific approval from Imo Pump.
Table 1 – Normal Pump Operating and Structural Limits
Condition Limit
Maximum Speed 4400 rpm for 137 size
2500
r
pm for 350 size
Minimum Viscosity 32 SSU
Maximum Viscosity (figure 1)
1st Letter Designator B 2500 SSU
1st Letter Designator H 20000 SSU
Minimum Liquid Temperature 0°F
Maximum Liquid Temperature (figure 1)
1st Letter Designator B 180°F
1st Letter Designator H 220°F
Maximum Inlet Pressure 75 psig for 137 size
50 psig for 350 size
Maximum Discharge Pressure (Continuous Duty) 2200 psig
Filtration Refer to General Instruction Manual,
SRM00046
Drive Direct or Belt
Mounting Foot mounted in any attitude

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G. PARTS LIST
Table 2 – Pump Parts List
IDP QTY DESCRIPTION KIT IDP QTY DESCRIPTION KIT
1 1 Case 43 2 Bearin
g
Retainer
2 1 Inlet Head 46 1 Inboard Cover
4 4 Cap Screws
(
Qt
y
. 16 on 350 Size
)
47 2 Bearing Retainer Hex Bolts
5 2 Pipe Plug
(
137 C-Face Steel Case Onl
y)
48 1 Seal Seat Adapter
6 1 Pin Stop 49 1 Ball Bearin
g
X
7 1 Fastener Seal X 63 1 Power Rotor XX
8 2 Housin
g
Snap Rin
g
s XX 67 2 Pipe Plu
g
9 2 Cover Gasket or O-rin
g
s X 68 1 Tube Fittin
g
(
350 Size Onl
y)
21 2 Suction Idlers XX 69 1 Pipe Nipple
(
350 Size Onl
y))
22 1 Balance Piston Housing
(
350 Size Onl
y)
XX 70 1 Tubing Fitting
23 2 Cups XX 71 1 Seal Pipe
24 1 Suction Housin
g
XX 73 3 Inlet Housin
g
XX
25 1 Mechanical Seal X 74 1 Pipe Fittin
g
26 3 Housing Tube
(
Qt
y
. 4 on 350 Size
)
83 1 Seal Gasket X
27 8 Tube O-Rings X 86 1 Balance Piston Bushing
(
137 C-Face Onl
y)
X
28 2 Housin
g
& BP O-Rin
g
X 90 4 Cap Screws
(
137 Size Onl
y)
29 1 Thrust Plate XX 94 1 Shoulder Bolt
(
137 C-Face Onl
y)
31 1 Ke
y
100 1 Oil Balance Tube
35 6 Dischar
g
e Idlers XX 101 2 Thrust Plate Spacer
38 2 Seal Spacer
(
350 Size Onl
y)
102 2 Thrust Plate Hex Bolt
42 2 Bearin
g
Retainin
g
Rin
g
s X
X = Minor Repair Kit Items.
XX = Ma
j
or Repair Kit Items.
(
Items marked
(
X
)
are included in Ma
j
or Repair Kit.
)
H. PUMP MAINTENANCE
WARNING
Failure to observe precautions while installing, inspecting and maintaining pump can cause
injury to personnel from accidental handling of liquids that may harm skin or clothing, or fire
hazard risks from flammable liquids, or injury from high pressure fluid jets.
DANGER
BEFORE working on equipment, make sure all power to equipment is disconnected and
locked-out.
H.1 GENERAL COMMENTS
NOTE: Part number identifiers (IDP) contained within parenthesis, such as (9), refer to assembly
drawing
De-energize driver before starting with any maintenance action.

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H.2 TOOLS REQUIRED
Procedures described in this manual require common mechanics hand tools, a torque wrench, dial
indicators for alignment and a suitable lifting device such as slings, straps, etc.
H.3 Pump Disassembly Procedure
CAUTION
Fluid leakage from disassembly of pump may make floor slippery and cause personal injury
NOTE: To service mechanical seal and ball bearing only, perform H.3, steps 1 thru 5 and H.4,
Steps 13 through 18.
Refer to appropriate assembly drawings, Figures 3, 4 an 5, for the following instructions.
1. Close suction and discharge valves. Drain pump by removing drain plugs (67). Remove seal
tubing (71). Remove pump from driver, coupling and base plate. Remove coupling hub and
key (31).
2. Remove bearing retainer (43) from inboard cover (46) by removing bolts (47).
3. Remove assembled power rotor (63) from inboard cover (46). Removal of power rotor (63)
includes removal of snap rings (42), ball bearing (49), seal (25), seal seat adapter (48) and, for
350 size spacer (38).
.

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4. Disassemble power rotor (63) as follows (See Figure 1 for seal drawings) :
a. Using a flat nosed tool, such as a screw driver, remove both snap rings (42) from groove
in power rotor (63).
b. Sealed ball bearing (49) is assembled to power rotor (63) with light press fit. Ball bearing
(49) may be removed by using bearing puller or vertical arbor press. When using press,
place two pieces of key stock through openings of mechanical seal seat adapter (48)
underneath ball bearing (49) on both sides of power rotor shaft. Key stock should be
long enough to support power rotor (63) as it is placed in press. Position press ram
against power rotor (63) coupling end face. Gently press power rotor (63) through ball
bearing (49)
CAUTION ATTENTION
Ensure power rotor (63) does not fall to floor once ball bearing (49) is off of its diameter
c. Remove seal seat adapter (48) with stationary seal seat. Remove stationary seat with O-
ring from seal seat adapter (48). Discard O-ring.
d. If seal is multi-spring type, disengage set screw and remove rotating seal seat. If seal is a
single spring rubber bellows type, remove it from shaft with a rotating motion.
e. Remove spacer (38) from shaft if size 350.
5. Remove seal gasket (83) from inboard end cover (46).
6. Remove inboard cover (46) by removing bolts (4).
7. If pump is a 137 size C-face type, remove O-ring (28) from inboard cover (46) shoulder bolt
(94) from inboard cover (46) and balance piston bushing (22) from inboard cover (46).
8. If pump is 137 foot mount type or 350 size, remove gasket (9) from inboard cover (46).
9. Remove inlet head (2) from case (1) by removing bolts (4). Remove and discard gasket (9)
from inlet head (2).
10. Remove thrust plate (29) and spacers (101) by removing bolts (102).
11. Remove seal return tube (100) with O-rings (27). Remove and discard O-rings (27).
12. Remove cups (23) from idlers (21) and idlers (21, 35) from housings (73, 24).
CAUTION ATTENTION
Do not permit idlers (19) to drop as they emerge from housing (2).
13. Remove snap rings (8) from case (1). Remove pin stop (6) with fastener seal (7) from case
(1). Discard fastener seal (7)
14. If pump is a 350 size or 137 size foot mount , remove balance piston housing (22) by pushing
it out through discharge end of case (1) with housings (73, 24). Remove and discard
balance piston housing O-ring (28).

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15. Remove housings (73, 24) by continuing to push them out through discharge end of the case
(1). Remove and discard housing O-ring (28). Remove tubes (26) and O-rings (27) from
housings (24 or 73). Discard O-rings (27)
CAUTION ATTENTION
Do not permit housings (73, 24) to drop as they are removed from pump.
H4. Pump Reassembly Procedure:
Note: Prior to reassembly, all parts should be cleaned and inspected for nicks and burrs. Replace
all worn and damaged parts. Imo pump recommends replacement of ball bearing (49), mechanical
seal (25), gaskets (9, 83, 6), fastener seal (7) and O-rings (28) when these parts are disturbed
from their original installed position. All parts should be coated with light lubricating oil to assist in
assembly.
1. Install O-ring (28) in groove in housing (24). Install O-rings (27) in grooves in all but one tube
(26 and 100). Install a tube (26) with O-rings (27) in housing (24) on opposite side of housing
O-ring (28).
2. Install housing (24), O-ring end first, in pump case (1) from suction end until stop pin (6) slot is
properly aligned. Install stop pin (6) with fastener seal (7) in case (1).
3. Inlet 1st inlet housing (73) in pump case (1) with end that has two drilled and tapped holes
facing inlet end of pump. Be sure that tube (26) in housing (24) mates to hole in housing (73).
4. Install tube (26) with O-rings (27) in back side of first inlet housing (73) and then install second
inlet housing (73) being sure that tube (26) in first housing (27) mates to hole in second
housing (73).
5. Repeat step 4 with last inlet housing (73)
6. Install snap rings (8) in case (1).
7. If pump is 350 size, proceed below. If not skip to step 12.
8. Install tube (26) without O-rings (27) in discharge housing (24) side facing outlet side of pump
and install O-ring (28) on balance piston housing (22).
9. Install balance piston housing (22) in pump case being sure that idler stops on balance piston
housing (22) are lined up with idler bores and pin hole in balance piston housing (22) lines up
with pin (26) on discharge housing (24)
10. Install gasket (9) on inboard cover.
11. Install inboard cover (46) in case (1) using bolts (4). Ensure seal vent (70) is facing up. Torque
bolts (4) to value on appropriate assembly drawing. Skip to step 16
12. If pump is 137 size, C-face type, install balance piston bushing (86) in inboard cover (46) with
shoulder bolts (94), O-ring (28) in inboard cover (46) and inboard cover (46) in case (1) with
bolts (90). Torque bolts to value on assembly drawing. Ship to step 16.
13. If pump is 137 size, foot mount type, proceed below.

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14. Install O-ring (28) on balance piston housing (22). Install balance piston housing (22) onto
inboard cover (46) being sure that roll pin in balance piston housing (22) mates to slit in
inboard cover (46).
15. Install inboard cover (46) / balance piston housing (22) assembly in case with bolts (90) being
sure that seal drain (70) in inboard cover (46) is positioned at 12 o-clock. Torque bolts (4) to
value on appropriate assembly drawing
16. Assemble power rotor (63) and mechanical seal (25) as follows (See Figure 1 for seal
drawings):
a. If size 350, assemble seal spacer (38) onto shaft (63).
b. If seal is a single spring rubber bellows type, apply light coat of system fluid to inside
diameter of bellows and slide mechanical seal rotating assembly on power rotor (63) until it
seats against the shoulder of seal spacer (38). Wipe seal face with isopropyl alcohol and a
lint free rag.
c. If seal is a multi-spring seal, coat O-ring inside of rotating seat with system fluid and slide
mechanical seal rotating assembly on power rotor (63) until it seats against the shoulder of
seal spacer (38). Tighten rotating seat set screw. Wipe seal face with isopropyl alcohol
and a lint free rag.
d. Install O-ring in groove of mechanical seal stationary seat. Install seat including O-ring in
seal seat adapter (48) ensuring that slot in back of stationary seat mates to spring pin in
seal seat adapter (48). Clean seal face with isopropyl alcohol and a lint free rag. Put a
small amount of clean system fluid or light oil on seal running face. Install the stationary
seat running face against the rotating seat face.
e. Install inner snap ring (42) in groove of power rotor (63).
f. Press bearing (49) on power rotor (63), pressing only on inner race of ball bearing (49)
using an installation sleeve until it is located next to inner snap ring (42).
CAUTION ATTENTION
Bearing service life could be significantly reduced if bearing is pushed on by its outer race.
g. Install outer snap ring (42) in groove of power rotor (63).
17. Install gasket (83) in seal bore of inboard cover (46).
18. Install assembled power rotor (63) in pump, centering all parts as they enter inboard cover
(46). Align one of openings in spacer (48) over drain in inboard cover (46).
19. Install bearing retainer (43) on inboard cover (46) using bolts (47). Torque bolts (47) to value
on appropriate assembly drawing.
20. Install idlers (35 and then 21) into housings (24, 73) by meshing threads with power rotor
thread
21. Install cups (23) on idlers (21).
22. Install bolts (102) in thrust plate (29) and spacers (101) on bolts (102).

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23. Install thrust plate assembly including thrust plate (29), bolts (102) and spacers (101) on
housing (73). Torque bolts (102) to value on appropriate assembly drawing.
24. Install gasket (9) in groove in inlet head (2), and install inlet head (2) on case (1) using hex
bolts (4). Torque bolts (4) to value on appropriate assembly drawing
NOTE: Inlet head (2) can be rotated and repositioned in 90 degree increments to suit suction
piping. To change inlet position remove bolts (4) and rotate inlet head to desired position. Install
bolts (4) and torque to proper values indicated on assembly drawing.
25. Install coupling hub key (16). Install and align pump and driver as specified in General
Instruction Manual, SRM00046.
I. TROUBLESHOOTING
For assistance with troubleshooting see the General Instruction Manual, SRM00046.
J. FIELD AND FACTORY SERVICE AND PARTS
Imo Pump maintains a staff of trained service personnel that can provide pump installation, pump start-
up, maintenance/overhaul and troubleshooting supervision as well as installation and maintenance
training.
Our factories provide maintenance as well as overhaul and test facilities in the event user prefers to
return pumps for inspection or overhaul. Factory-overhauled pumps are normally tested and warranted
“as-new” for a period of one year from date of shipment. For either field service or factory overhaul
assistance, contact your local Imo Sales Office or representative at Technical/ Customer Service
Department in Monroe, NC, USA.
Most pumps have repair kits available. Minor Repair Kits are used to repair leaking seals, bad bearings
and/or for re-assembly after pump tear-down. They include pump shaft seals all gaskets/O-rings and
bearings. Major Repair Kits are sufficient to rebuild completely worn-out pumps to “as-new” condition.
They include all parts found in Minor Repair Kits plus all major internal parts subject to wear. Since kits
have all necessary parts, kit purchase is preferred rather than selecting individual parts. When parts are
individually selected from Parts List, some needed components are often overlooked. In addition, mixing
worn or used parts with new parts risks rapid wear and shortened service life from new parts.

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CIRCOR
1710 Airport Road
PO Box 5020
Monroe, NC USA
28111.5020
Tel: [phone]
Email: [e-mail]
Web: www.circorpt.com
© 2020 CIRCOR Pumps North America, LLC. All rights reserved.