Circor IMO RG3D-275 Series User manual

INSTRUCTION MANUAL
AND
PARTS LIST
FOR
PG/RG3D-275 SERIES PUMPS
(Idler Cup and Hydrostatic Thrust Designs)
WARNING
This Instruction Manual and General Instructions Manual, CA-1, should be read
thoroughly prior to pump installation, operation or maintenance.
Manual No. SRM00081 Rev. 01 August 2020

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, O-rings, shaft seal and bearings) should be kept in stock so
pump refurbishment after internal inspection can be accomplished.
CONTENTS
Safety and Table of Contents .......................................................................................................A
A. General Instructions................................................................................................................ 1
B. Introduction ............................................................................................................................. 1
C. Description of Equipment........................................................................................................ 1
D. Pump Model Identification....................................................................................................... 2
E. Ordering Instructions............................................................................................................... 2
F. Operation ............................................................................................................................... 3
G. Parts List ................................................................................................................................. 4
H. Pump Maintenance ................................................................................................................. 4
I. Troubleshooting ...................................................................................................................... 9
J. Field and Factory Service and Parts....................................................................................... 9
K. Assembly Drawings .............................................................................................................. 10
L. Mechanical Seal Drawings.................................................................................................... 11
A

A. GENERAL INSTRUCTIONS
The instructions found herein cover the disassembly, assembly and parts identification of
PG/RG3D-275 series pumps. Both the original design with idler cups and the newer design with
hydrostatic idlers are covered.
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 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 PG/RG3D-275 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
PG/RG3D-275 Series pumps are positive displacement, rotary screw pumps consisting of a precision
bored housing which encloses a driven screw (power rotor) and two 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.
1

D. PUMP MODEL IDENTIFICATION
This instruction manual covers Imo Series PG/RG3D-275 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.
Figure 1 – Model Designator Definitions
X G 3D X X X X XXX X
Series
1st Letter Designator (Seal Design)
N – Metal Bellows Seal Viton Fitted
Y – Metal Bellows Seal Neoprene Fitted
G – Design Modification
Lead and Rotation
Blank = 2D, CW ; D – 2D, CCW
E = 1.7D, CW ; J = 1.6D, CW
Rotor Size
275
4th Letter Designator
J – Silicon Carbide Seat
X – Special Material Or Construction
3rd Letter Designator
S – Steel casing
X – Special Material Or Construction
2nd Letter Designator
C – Circular Mounting Flange
R – Axial Inlet
S – Steel Casing
X – Special Material Or Construction
Basic Pump Modifiers
P – High Inlet Pressure
___for 25 to 125 psid
R – High Vacuum Service
__ for over 125 psid
E. ORDERING INSTRUCTIONS
When corresponding with Imo Pump regarding Series PG/RG3D-275 series 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 (see figure 2) 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, CA-1.
2

F. OPERATION
F.1 LIQUID LIMITATIONS
Never operate with thin liquids such as solvents or water. Pump is designed for liquids having
general characteristics of oil.
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 2500 rpm
Minimum Viscosity 32 SSU
Maximum Viscosity (figure 1) 2500 SSU
Minimum Liquid Temperature 0°F
Maximum Liquid Temperature (figure 1) 200°F
Maximum Inlet Pressure 300 Psig
Maximum Discharge Pressure (Continuous Duty) 500 psig
Filtration Refer to General Instruction Manual, CA-1
Drive Direct or Belt
Mounting Foot mounted in any attitude
3

G. PARTS LIST
Table 2 – Pump Parts List
IDP QTY DESCRIPTION KIT IDP QTY DESCRIPTION KIT
1 1 Case 18 4 Hex Bolts
2 1 Housing XX 19 2 Idle
r
Roto
r
XX
3 1 Pipe Plug 20 2 Idler Cups (Idler Cup Design
Only)
XX
4 1
A
nti-Rotation Tube XX 21 1 Thrust Plate XX
5 2 O-ring X 22 2 Thrust Space
r
6 1 O-ring X 23 2 Hex Cap Screws
7 1 O-ring X 24 2 Washe
r
9 1 Inboard Cover 25 1 Mechanical Seal X
10 16 Hex Bolts 26 1 Inlet
11 1 Power Roto
r
XX 28 1 Space
r
13 2 Retaining Rings X 38 1 Seal Spacer X
14 1 Spacer/Seal Seat Adapte
r
68 3 Pipe Plug
15 1 Bearing X 72 1 O-ring X
16 1 Key X 81 1 O-ring* X
17 1 Bearing Retainer 86 1 Bushing XX
X = Minor Repair Kit Items.
XX = Major Repair Kit Items. (Items marked (X) are included in Major 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
circled numbers shown on assembly drawing, figure 2.
De-energize driver before starting with any maintenance action.
4

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 MECHANICAL SEAL AND BEARING MAINTENANCE
The following procedures detail servicing the pump mechanical seal and ball bearings only.
Refer to pump assembly shown by figure 2 and mechanical seal assembly shown by figure
3 for the following instructions.
1. Close suction and discharge piping to pump. Vent pressure from pump. Disconnect
piping. Remove drain plug (68) and drain unit. Remove pump from driver, coupling
and base plate. Remove coupling hub and key (16).
2. Remove bearing retainer (17) from inboard cover (9) by removing bolts (18).
3. Remove assembled power rotor (11) from inboard cover (9). Removal of power rotor
(11) includes removal of snap rings (13), ball bearing (15), seal spacer (38), seal seat
adapter (14) and mechanical seal (25).
4. Disassemble power rotor (11) as follows:
a. Using a flat nosed tool, such as a screw driver, remove snap ring (13) located
on coupling side of ball bearing (15) from groove in power rotor (11).
b. Sealed ball bearing (15) is assembled to power rotor (11) with light press fit.
Ball bearing (15) 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 (14) underneath ball bearing (15) on both sides of
power rotor shaft. Key stock should be long enough to support power rotor (11)
as it is placed in press. Position press ram against power rotor (11) coupling
end face. Gently press power rotor (11) through ball bearing (15). Ensure
power rotor (11) does not fall to floor once ball bearing (15) is off of its diameter.
c. Remove thread side snap ring (13).
d. Remove seal seat adapter (14) with stationary seal seat. Remove stationary
seat with O-ring from seal seat adapter (14). Discard O-ring.
e. Remove rotating seal seat by disengaging set screw, then sliding seal seat off
shaft (11).
f. Remove spacer (38) from shaft.
5. Remove O-ring (81) from inboard end cover (9).
5

6. Inspect power rotor (11) shaft and remove any nicks or burrs which are present. Polish
power rotor shaft to remove any rust or oxidants that may be present under shaft
sleeve. Imo pump recommends replacement of ball bearing (15), mechanical seal (25),
and O-ring (81) when these parts are disturbed from their original installed position. All
parts should be coated with light lubricating oil to assist in assembly.
7. Assemble power rotor (11) and mechanical seal (25) as follows:
a. Assemble spacer (38) onto shaft (11).
b. Slide mechanical seal rotating assembly on power rotor (11) until it seats
against seal spacer (38). Tighten seal set screw on shaft.
c. 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 (14) ensuring that groove in back of stationary seat
mates to spring pin in seal seat adapter (14). 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 rotating ring running face against the stationary
seat face.
e. Install inner snap ring (13) in groove of power rotor (11).
f. Press bearing (15) on power rotor (11), pressing only on inner race of ball
bearing (15) using an installation sleeve until it is located next to inner snap ring
(13).
g. Install outer snap ring (13) in groove of power rotor (11).
8. Install O-ring (81) in seal bore of inboard cover (9).
9. Install assembled power rotor (11) in pump, centering all parts as they enter inboard
cover (9). Align one of openings in spacer (14) over drain in inboard cover (9).
10. Install bearing retainer (17) on inboard cover (9) using bolts (18) (and lockwashers (30)
if present). Torque bolts (18) to value indicated on assembly drawing, figure 2.
6

H.4 PUMP DISASSEMBLY
CAUTION
Fluid leakage from disassembly of pump may make the floor slippery and can
cause personal injury
.
NOTE: The PG/RG3D-275 pumps incorporate highly finished precision parts that must
be handled carefully to avoid damage to critical machined surfaces. The parts
removed should be tagged for identification and their exact positions in the pump
carefully noted so that new parts, or the same parts, are properly replaced
without damage.
Refer to pump assembly shown in figure 2 for the following instructions.
1. Close suction and discharge piping to pump. Vent pressure from pump. Disconnect
piping. Remove drain plug (68) and drain unit. Remove pump from driver, coupling
and base plate. Remove coupling hub and key (16).
2. Remove inlet head (26) from case (1) by removing bolts (10). Remove and discard O-
ring (72) from inlet head (26).
3. Remove thrust plate (21) and spacers (22) by removing bolts (23) and lock washers
(24).
4. If idler cup design, remove cups (20) from idlers (19).
5. Remove idlers (19) from housing (2) by unscrewing them from housing bores.
CAUTION ATTENTION
Do not permit idlers (19) to drop as they emerge from housing (2).
6. Remove housing spacer (28) from case (1).
7. Remove shaft (11) with ball bearing (15) and seal (25) by performing procedures in
paragraph H.3 steps (2) through (6).
8. Remove inboard cover (9) by removing bolts (10).
9. Press bushing (86) from cover (9). Cover may require heating to loosen Loctite before
bushing (86) can be removed. Do not heat to more than 250°F.
10. Remove and discard O-ring (7) from inboard cover (9).
11. Remove tube (4) with O-rings (5) from housing (2). Discard O-rings (5).
12. Remove housing (2) and O-ring (6) from inlet end of case (1). Discard O-ring (6).
7

H.5 PUMP ASSEMBLY
NOTE: Prior to reassembly of pump, clean and inspect all parts for nicks and burrs.
Replace all worn or damaged parts. Imo Pump recommends replacement of all
O-rings (6), mechanical seal (25), and ball bearing (15) when these parts are
disturbed from their previously installed positions. Coat all parts with light
lubricating oil to assist in assembly.
1. Install O-ring (6) in groove in housing (2). Install O-rings (5) in grooves in tube (4) and
install tube (4) in housing (2).
2. Install housing (2), O-ring end first, in pump case (1) from suction end.
3. Clean and dry inboard cover (9) and balance piston bushing (86) mating surfaces with
solvent. Wipe Loctite “T747” Primer or equivalent onto the mating surfaces of bushing
(86) and inboard cover (9). Allow 1 to 5 minutes until primer is visibly dry. Apply
Locitite 609 or equivalent to bushing (86) and inboard cover (9) mating surfaces.
4. Assemble bushing (81) into inboard cover (9). Allow 10 minutes to dry before
proceeding with assembly.
5. Install O-ring (7) on inboard cover. Install inboard cover (9) into discharge port side of
case (1) using bolts (10). Ensure pin (4) in housing mates with hole in inboard cover
(9). Torque bolts (10) to value indicated on assembly drawing, figure 2.
6. Assemble mechanical seal and ball bearings by performing procedures in paragraph
H.3, steps 7 through 10.
7. Install idlers (19) into housing (2) by meshing threads with power rotor thread.
8. If idler cup design, install cups (20) on idlers (19).
9. Install spacer (28) on discharge end of case (1) flush with edge of housing (2).
10. Install bolts (23) and lock washers (24) in thrust plate (21). Install spacers (22) on bolts
(23).
11. Install thrust plate assembly including thrust plate (21), washers (24), bolts (23) and
spacers (22) on housing (2). Torque bolts (23) to value indicated on assembly drawing,
figure 2.
12. Install O-ring (72) in groove in inlet head (26).
13. Install inlet head (26) using bolts (10). Torque bolts to value indicated on assembly
drawing, figure 2.
NOTE: Inlet head (26) can be rotated and repositioned in 90 degree increments to suit
suction piping. To change inlet position remove bolts (10) and rotate inlet head
to desired position. Install bolts (10) and torque to proper values indicated on
assembly drawing, figure 2.
14. Install coupling hub key (16). Install and align pump and driver as specified in General
Instruction Manual, CA-1.
8

I. TROUBLESHOOTING
For assistance with troubleshooting see the General Instruction Manual, CA-1.
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 the in 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 (as applicable) pump shaft seals, packing,
all O-rings/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.
9

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.