Flowserve Durco Mark 3 ISO Frame Mounted User Manual

USER INSTRUCTIONS

Durco® Mark 3™ ISO frame mounted

Installation

Operation

Maintenance

Standard two piece bearing frame foot mounted, centerline
mounted and unitized self-priming chemical process pumps

PCN= 85392719 12-14 (E). Original instructions.

These instructions must be read prior to installing,

operating, using and maintaining this equipment.

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

CONTENTS

Page

1 INTRODUCTION AND SAFETY ........................ 4

1.1 General ......................................................... 4

1.2 CE marking and approvals ........................... 4

1.3 Disclaimer ..................................................... 4

1.4 Copyright....................................................... 4

1.5 Duty conditions ............................................. 4

1.6 Safety ............................................................ 5

1.7 Nameplate and safety labels ........................ 9

1.8 Specific machine performance ..................... 9

1.9 Noise level .................................................... 9

2 TRANSPORT AND STORAGE ........................ 10

2.1 Consignment receipt and unpacking .......... 10

2.2 Handling ...................................................... 10

2.3 Lifting .......................................................... 10

2.4 Storage ....................................................... 11

2.5 Recycling and end of product life ............... 11

3 DESCRIPTION ................................................ 11

3.1 Configurations ............................................. 11

3.2 Name nomenclature ................................... 11

3.3 Design of major parts .................................. 12

3.4 Performance and operating limits ............... 12

4 INSTALLATION ................................................ 13

4.1 Location ...................................................... 13

4.2 Part assemblies .......................................... 13

4.3 Foundation .................................................. 13

4.4 Grouting ...................................................... 14

4.5 Initial alignment ........................................... 14

4.6 Piping .......................................................... 15

4.7 Electrical connections ................................. 20

4.8 Final shaft alignment check ........................ 20

4.9 Protection systems ..................................... 20

Page

6 MAINTENANCE .............................................. 25

6.1 General ....................................................... 25

6.2 Maintenance schedule ............................... 26

6.3 Spare parts ................................................. 27

6.4 Recommended spares ............................... 27

6.5 Tools required ............................................. 27

6.6 Fastener torques ........................................ 28

6.7 Setting impeller clearance .......................... 28

6.8 Disassembly ............................................... 29

6.9 Examination of parts ................................... 30

6.10 Assembly .................................................... 31

6.11 Sealing arrangements ................................ 33

7 FAULTS; CAUSES AND REMEDIES .............. 36

8 PARTS LISTS AND DRAWINGS ..................... 38

8.1 Mark 3 ISO ................................................. 38

8.2 Centerline mounted, recessed impeller

and self-primer configurations .................... 40

8.3 Additional details ........................................ 43

8.4 Parts interchangeability .............................. 45

8.5 General arrangement drawing .................... 49

9 CERTIFICATION ............................................. 49

10 OTHER RELEVANT DOCUMENTATION AND

MANUALS ....................................................... 49

10.1 Supplementary User Instruction manuals .. 49

10.2 Change notes ............................................. 49

10.3 Additional sources of information ............... 49

5 COMMISSIONING, START-UP, OPERATION

AND SHUTDOWN ........................................... 20

5.1 Pre-commissioning procedure .................... 20

5.2 Pump lubricants .......................................... 21

5.3 Impeller clearance ...................................... 22

5.4 Direction of rotation ..................................... 22

5.5 Guarding ..................................................... 22

5.6 Priming and auxiliary supplies .................... 22

5.7 Starting the pump ....................................... 23

5.8 Running the pump ...................................... 23

5.9 Stopping and shutdown .............................. 24

5.10 Hydraulic, mechanical and electrical duty .. 25

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DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

INDEX

Page

Additional sources (10.3) ......................................... 49

Alignment of shafting (see 4.3, 4.5 and 4.8)

Assembly (6.10) ....................................................... 31

ATEX marking (1.6.4.2) ............................................. 7

Bearing sizes and capacities (5.2.2) ....................... 21

CE marking and approvals (1.2) ................................ 4

Certification (9) ........................................................ 49

Change notes (10.2) ................................................ 49

Clearances, impeller (6.7) ....................................... 28

Commissioning and operation (5) ........................... 20

Compliance, ATEX (1.6.4.1) ...................................... 6

Configurations (3.1) ................................................. 11

Copyright (1.4) ........................................................... 4

Design of major parts (3.3) ...................................... 12

Direction of rotation (5.4) ......................................... 22

Disassembly (6.8) .................................................... 29

Disclaimer (1.3).......................................................... 4

Dismantling (6.8, Disassembly) ............................... 29

Drawings (8) ........................................................... 38

Duty conditions (1.5) .................................................. 4

Electrical connections (0) ........................................ 20

End of product life (2.5) ........................................... 11

Examination of parts (6.9) ....................................... 30

Fastener torques (6.6) ............................................. 28

Faults; causes and remedies (7) ............................. 36

Foundation (4.3) ...................................................... 13

General arrangement drawing (8.5) ........................ 49

General assembly drawings (8) ............................... 38

Grouting (4.4)........................................................... 14

Guarding (5.5).......................................................... 22

Handling (2.2) .......................................................... 10

Hydraulic, mechanical and electrical duty (5.10) ..... 25

Impeller clearance (see 5.3 and 6.7)

Inspection (6.2.1 and 6.2.2) ..................................... 26

Installation (4) .......................................................... 13

Lifting (2.3) ............................................................... 10

Location (4.1) ........................................................... 13

Lubrication (see 5.1.1, 5.2 and 6.2.3)
Lubrication schedule (see 6.2.3)

Maintenance (6) ....................................................... 25

Maintenance schedule (6.2) .................................... 26

Name nomenclature (3.2) ........................................ 11

Nameplate (1.7.1) ...................................................... 9

Nozzle loads (4.6.4) ................................................. 16

Operating limits (3.4.1) ............................................ 12

Ordering spare parts (6.3.1) .................................... 27

Part assemblies (4.2) ............................................... 13

Parts interchangeability (8.4) ................................... 45

Parts lists (8) ............................................................ 38

Performance (3.4) .................................................... 12

Piping (4.6) .............................................................. 15

Pre-commissioning (5.1) .......................................... 20

Priming and auxiliary supplies (5.6) ........................ 22

Page

Protection systems (4.9) ..........................................20

Reassembly (6.10, Assembly) .................................31

Receipt and unpacking (2.1) ....................................10

Recommended fill quantities (see 5.2.2) ..................21

Recommended grease lubricants (5.2.3) .................22

Recommended oil lubricants (5.2.1) ........................21

Recommended spares (6.4) .....................................27

Recycling (2.5) .........................................................11

Replacement parts (6.3 and 6.4) ..............................27

Running the pump (5.8) ...........................................23

Safety action (1.6.3) ................................................... 5

Safety labels (1.7.2) ................................................... 9

Safety markings (1.6.1) .............................................. 5

Safety, protection systems (see 1.6 and 4.9)

Sealing arrangements (6.11) ....................................33

Sectional drawings (8) ..............................................38

Setting impeller clearance (6.7) ...............................28

Sound pressure level (1.9, Noise level) ..................... 9

Sources, additional information (10.3) .....................49

Spare parts (6.3) ......................................................27

Specific machine performance (1.8) .......................... 9

Starting the pump (5.7).............................................23

Stop/start frequency (5.8.5) ......................................24

Stopping and shutdown (5.9) ...................................24

Storage, pump (2.4) .................................................11

Storage, spare parts (6.3.2) .....................................27

Supplementary manuals or information sources ......49

Supplementary User Instructions (10.1)...................49

Thermal expansion (4.5.1) .......................................14

Tools required (6.5) ..................................................27

Torques for fasteners (6.6) .......................................28

Trouble-shooting (see 7) ..........................................36

Vibration (5.8.4) ........................................................24

Page 3 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

1 INTRODUCTION AND SAFETY

1.1 General

These instructions must always be kept

close to the product's operating location or
directly with the product.

Flowserve products are designed, developed and
manufactured with state-of-the-art technologies in
modern facilities. The unit is produced with great
care and commitment to continuous quality control,
utilizing sophisticated quality techniques and safety
requirements.

Flowserve is committed to continuous quality
improvement and being at service for any further
information about the product in its installation and
operation or about its support products, repair and
diagnostic services.

These instructions are intended to facilitate
familiarization with the product and its permitted use.
Operating the product in compliance with these
instructions is important to help ensure reliability in
service and avoid risks. The instructions may not
take into account local regulations; ensure such
regulations are observed by all, including those
installing the product. Always coordinate repair
activity with operations personnel, and follow all plant
safety requirements and applicable safety and health
laws and regulations.

These instructions must be read prior to
installing, operating, using and maintaining the
equipment in any region worldwide. The
equipment must not be put into service until all the
conditions relating to safety, noted in the
instructions, have been met. Failure to follow and
apply the present user instructions is considered
to be misuse. Personal injury, product damage,
delay or failure caused by misuse are not covered
by the Flowserve warranty.

1.2 CE marking and approvals

It is a legal requirement that machinery and equipment
put into service within certain regions of the world shall
conform with the applicable CE Marking Directives
covering Machinery and, where applicable, Low Voltage
Equipment, Electromagnetic Compatibility (EMC),
Pressure Equipment Directive (PED) and Equipment for
Potentially Explosive Atmospheres (ATEX).

Where applicable, the Directives and any additional
Approvals, cover important safety aspects relating to
machinery and equipment and the satisfactory provision

of technical documents and safety instructions. Where
applicable this document incorporates information
relevant to these Directives and Approvals.

To confirm the Approvals applying and if the product is
CE marked, check the serial number plate markings
and the Certification. (See section 9, Certification.)

1.3 Disclaimer

Information in these User Instructions is believed to
be complete and reliable. However, in spite of all of
the efforts of Flowserve Corporation to provide
comprehensive instructions, good engineering and
safety practice should always be used.

Flowserve manufactures products to exacting
International Quality Management System Standards as
certified and audited by external Quality Assurance
organizations. Genuine parts and accessories have
been designed, tested and incorporated into the
products to help ensure their continued product quality
and performance in use. As Flowserve cannot test
parts and accessories sourced from other vendors the
incorrect incorporation of such parts and accessories
may adversely affect the performance and safety
features of the products. The failure to properly select,
install or use authorized Flowserve parts and
accessories is considered to be misuse. Damage or
failure caused by misuse is not covered by the
Flowserve warranty. In addition, any modification of
Flowserve products or removal of original components
may impair the safety of these products in their use.

1.4 Copyright

All rights reserved. No part of these instructions may
be reproduced, stored in a retrieval system or
transmitted in any form or by any means without prior
permission of Flowserve.

1.5 Duty conditions

This product has been selected to meet the
specifications of your purchase order. The
acknowledgement of these conditions has been sent
separately to the Purchaser. A copy should be kept
with these instructions.

The product must not be operated beyond

the parameters specified for the application.

If there is any doubt as to the suitability of the
product for the application intended, contact

Flowserve for advice, quoting the serial number.

If the conditions of service on your purchase order are
going to be changed (for example liquid pumped,
temperature or duty) you should seek the written

agreement of Flowserve before start up.

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1.6 Safety

1.6.1 Summary of safety markings

These User Instructions contain specific safety
markings where non-observance of an instruction would
cause hazards. The specific safety markings are:

This symbol indicates electrical safety
instructions where non-compliance will involve a high
risk to personal safety or the loss of life.

This symbol indicates safety instructions where

non-compliance would affect personal safety and could
result in loss of life.

This symbol indicates “hazardous and toxic fluid”
safety instructions where non-compliance would affect
personal safety and could result in loss of life.

This symbol indicates safety instructions

where non-compliance will involve some risk to safe
operation and personal safety and would damage the
equipment or property.

This symbol indicates explosive atmosphere zone
marking according to ATEX. It is used in safety
instructions where non-compliance in the hazardous
area would cause the risk of an explosion.

This symbol is used in safety instructions to

remind not to rub non-metallic surfaces with a dry
cloth; ensure the cloth is damp. It is used in safety
instructions where non-compliance in the hazardous
area would cause the risk of an explosion.

This sign is not a safety symbol but indicates

an important instruction in the assembly process.

1.6.2 Personnel qualification and training

All personnel involved in the operation, installation,
inspection and maintenance of the unit must be
qualified to carry out the work involved. If the personnel
in question do not already possess the necessary
knowledge and skill, appropriate training and instruction
must be provided. If required the operator may
commission the manufacturer/supplier to provide
applicable training.

Always coordinate repair activity with operations and
health and safety personnel, and follow all plant
safety requirements and applicable safety and health
laws and regulations.

1.6.3 Safety action

This is a summary of conditions and actions to help
prevent injury to personnel and damage to the
environment and to equipment. For products used
in potentially explosive atmospheres section 1.6.4

also applies.

NEVER DO MAINTENANCE WORK

WHEN THE UNIT IS CONNECTED TO POWER

GUARDS MUST NOT BE REMOVED WHILE

THE PUMP IS OPERATIONAL

DRAIN THE PUMP AND ISOLATE PIPEWORK

BEFORE DISMANTLING THE PUMP
The appropriate safety precautions should be taken
where the pumped liquids are hazardous.

FLUORO-ELASTOMERS (When fitted.)

When a pump has experienced temperatures over
250 ºC (482 ºF), partial decomposition of fluoro­elastomers (example: Viton) will occur. In this
condition these are extremely dangerous and skin
contact must be avoided.

HANDLING COMPONENTS

Many precision parts have sharp corners and the
wearing of appropriate safety gloves and equipment
is required when handling these components. To lift
heavy pieces above 25 kg (55 lb) use a crane
appropriate for the mass and in accordance with
current local regulations.

THERMAL SHOCK

Rapid changes in the temperature of the liquid within
the pump can cause thermal shock, which can result
in damage or breakage of components and should be
avoided.

NEVER APPLY HEAT TO REMOVE IMPELLER

Trapped lubricant or vapor could cause an explosion.

HOT (and cold) PARTS

If hot or freezing components or auxiliary heating
supplies can present a danger to operators and
persons entering the immediate area action must be
taken to avoid accidental contact. If complete
protection is not possible, the machine access must
be limited to maintenance staff only, with clear visual
warnings and indicators to those entering the
immediate area. Note: bearing housings must not be
insulated and drive motors and bearings may be hot.

If the temperature is greater than 80 ºC (175 ºF) or

below -5 ºC (23 ºF) in a restricted zone, or exceeds
local regulations, action as above shall be taken.

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DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

HAZARDOUS LIQUIDS

When the pump is handling hazardous liquids care
must be taken to avoid exposure to the liquid by
appropriate siting of the pump, limiting personnel
access and by operator training. If the liquid is
flammable and or explosive, strict safety procedures
must be applied.

Gland packing must not be used when pumping

hazardous liquids.

PREVENT EXCESSIVE EXTERNAL

PIPE LOAD
Do not use pump as a support for piping. Do not mount
expansion joints, unless allowed by Flowserve in
writing, so that their force, due to internal pressure, acts
on the pump flange.

NEVER RUN THE PUMP DRY

ENSURE CORRECT LUBRICATION
(See section 5, Commissioning, startup, operation and
shutdown.)

ONLY CHECK DIRECTION OF

MOTOR ROTATION WITH COUPLING ELEMENT/
PINS REMOVED
Starting in reverse direction of rotation will damage the
pump.

START THE PUMP WITH OUTLET
VALVE PART OPENED
(Unless otherwise instructed at a specific point in the
User Instructions.)

This is recommended to minimize the risk of
overloading and damaging the pump or motor at full or
zero flow. Pumps may be started with the valve further
open only on installations where this situation cannot
occur. The pump outlet control valve may need to be
adjusted to comply with the duty following the run-up
process. (See section 5, Commissioning start-up,
operation and shutdown.)

INLET VALVES TO BE FULLY OPEN

WHEN PUMP IS RUNNING
Running the pump at zero flow or below the
recommended minimum flow continuously will cause
damage to the pump and mechanical seal.

1.6.4 Products used in potentially explosive
atmospheres

Measures are required to:

 Avoid excess temperature
 Prevent build up of explosive mixtures
 Prevent the generation of sparks
 Prevent leakages
 Maintain the pump to avoid hazard

The following instructions for pumps and pump units
when installed in potentially explosive atmospheres
must be followed to help ensure explosion protection.
For ATEX, both electrical and non-electrical equipment
must meet the requirements of European Directive
2014/34/EU (previously 94/9/EC which remains valid
until 20 April 2016 during the transition). Always
observe the regional legal Ex requirements eg Ex
electrical items outside the EU may be required certified
to other than ATEX eg IECEx, UL.

Scope of compliance 1.6.4.1

Use equipment only in the zone for which it is

appropriate. Always check that the driver, drive

coupling assembly, seal and pump equipment are
suitably rated and/or certified for the classification of the
specific atmosphere in which they are to be installed.

Where Flowserve has supplied only the bare shaft
pump, the Ex rating applies only to the pump. The
party responsible for assembling the ATEX pump set
shall select the coupling, driver and any additional
equipment, with the necessary CE Certificate/
Declaration of Conformity establishing it is suitable
for the area in which it is to be installed.

The output from a variable frequency drive (VFD) can
cause additional heating effects in the motor and so,
for pumps sets with a VFD, the ATEX Certification for
the motor must state that it is covers the situation
where electrical supply is from the VFD. This
particular requirement still applies even if the VFD is
in a safe area.

DO NOT RUN THE PUMP AT

ABNORMALLY HIGH OR LOW FLOW RATES
Operating at a flow rate higher than normal or at a flow
rate with no back pressure on the pump may overload
the motor and cause cavitation. Low flow rates may
cause a reduction in pump/bearing life, overheating of
the pump, instability and cavitation/vibration.

Page 6 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Temperature class

to EN13463-1

Maximum surface

temperature permitted

Temperature limit of

liquid handled

T6
T5
T4
T3
T2
T1

85 °C (185 °F)
100 °C (212 °F)
135 °C (275 °F)
200 °C (392 °F)
300 °C (572 °F)
450 °C (842 °F)

65 °C (149 °F) *

80 °C (176 °F) *
115 °C (239 °F) *
180 °C (356 °F) *
275 °C (527 °F) *
400 °C (752 °F) *

Temperature class

to EN 13463-1

Maximum surface

temperature permitted

Temperature limit of

liquid handled

T6
T5
T4
T3
T2
T1

85 °C (185 °F)
100 °C (212 °F)
135 °C (275 °F)
200 °C (392 °F)
300 °C (572 °F)
450 °C (842 °F)

Consult Flowserve
Consult Flowserve

110 °C (230 °F) *
175 °C (347 °F) *
270 °C (518 °F) *
350 °C (662 °F) *

Marking 1.6.4.2

An example of ATEX equipment marking is shown
below. The actual classification of the pump will be
engraved on the nameplate.

II 2 GD c IIC 135 ºC (T4)

Equipment Group
I = Mining
II = Non-mining

Category
2 or M2 = high level protection
3 = normal level of protection

Gas and/or dust
G = Gas
D = Dust

c = Constructional safety

(in accordance with EN13463-5)

b = Control of ignition source

(in accordance with EN13463-6)
Gas Group

IIA – Propane (typical)
IIB – Ethylene (typical)
IIC – Hydrogen (typical)

Maximum surface temperature (Temperature Class)
(see section 1.6.4.3.)

Avoiding excessive surface 1.6.4.3

temperatures

ENSURE THE EQUIPMENT TEMPERATURE

CLASS IS SUITABLE FOR THE HAZARD ZONE
Pumps have a temperature class as stated in the

ATEX Ex rating on the nameplate. These are based
on a maximum ambient of 40 ºC (104 ºF); refer to
Flowserve for higher ambient temperatures.

The surface temperature on the pump is influenced
by the temperature of the liquid handled. The
maximum permissible liquid temperature depends on
the ATEX temperature class and must not exceed the
values in the table that follows.

Maximum permitted liquid temperature for pumps

Maximum permitted liquid temperature for pumps
with self-priming casing

* The table only takes the ATEX temperature class into consideration. Pump

design or material, as well as component design or material, may further
limit the maximum working temperature of the liquid.

The temperature rise at the seals and bearings and
due to the minimum permitted flow rate is taken into
account in the temperatures stated.

The operator is responsible to ensure that the
specified maximum liquid temperature is not

exceeded.

Temperature classification “Tx” is used when the liquid

temperature varies and when the pump is required to be
used in differently classified potentially explosive
atmospheres. In this case the user is responsible for
ensuring that the pump surface temperature does not
exceed that permitted in its actual installed location.

Avoid mechanical, hydraulic or electrical overload by
using motor overload trips, temperature monitors or a
power monitor and make routine vibration monitoring
checks.

In dirty or dusty environments, make regular checks
and remove dirt from areas around close clearances,
bearing housings and motors.

Where there is any risk of the pump being run against a
closed valve generating high liquid and casing external
surface temperatures fit an external surface
temperature protection device.

Pumps with threaded/locking screw on 1.6.4.4

impellers only

Do not attempt to check the direction of rotation with the
coupling element/pins fitted due to the risk of severe
contact between rotating and stationary components.

Pumps with key drive impellers only 1.6.4.5

If an explosive atmosphere exists during the
installation, do not attempt to check the direction of
rotation by starting the pump unfilled. Even a short
run time may give a high temperature resulting from
contact between rotating and stationary components.

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DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Additional requirements for self-priming 1.6.4.6

pumps only

Where the system operation does not ensure control of
priming, as defined in these User Instructions, and the
maximum permitted surface temperature of the T Class
could be exceeded, fit an external surface temperature
protection device.

Preventing the build-up of explosive 1.6.4.7

mixtures

ENSURE THE PUMP IS PROPERLY FILLED

AND VENTED AND DOES NOT RUN DRY

Ensure the pump and relevant suction and discharge
pipeline system is totally filled with liquid at all times
during the pump operation, so that an explosive
atmosphere is prevented.

In addition it is essential to make sure that seal
chambers, auxiliary shaft seal systems and any
heating and cooling systems are properly filled.

If the operation of the system cannot avoid this
condition, fit an appropriate dry run protection device
(for example liquid detection or a power monitor).

To avoid potential hazards from fugitive emissions of
vapor or gas to atmosphere the surrounding area
must be well ventilated.

Preventing sparks 1.6.4.8

To prevent a potential hazard from mechanical

contact, the coupling guard must be non-sparking.

To avoid the potential hazard from random induced
current generating a spark, the baseplate must be
properly grounded.

Avoid electrostatic charge: do not rub non-metallic

surfaces with a dry cloth; ensure cloth is damp.

For ATEX the coupling must be selected to comply
with the requirements of European Directive

2014/34/EU (previously 94/9/EC which remains valid
until 20 April 2016 during the transition). Correct
coupling alignment must be maintained.

Additional requirement for metallic 1.6.4.9

pumps on non-metallic baseplates

When metallic components are fitted on a non­metallic baseplate they must be individually earthed.

Preventing leakage 1.6.4.10

The pump must only be used to handle liquids
for which it has been approved to have the correct
corrosion resistance.

Avoid entrapment of liquid in the pump and associated
piping due to closing of suction and discharge valves,
which could cause dangerous excessive pressures to
occur if there is heat input to the liquid. This can occur if
the pump is stationary or running.

Bursting of liquid containing parts due to freezing
must be avoided by draining or protecting the pump
and ancillary systems.

Where there is the potential hazard of a loss of a seal
barrier fluid or external flush, the fluid must be
monitored.

If leakage of liquid to atmosphere can result in a
hazard, install a liquid detection device.

Maintenance to avoid the hazard 1.6.4.11

CORRECT MAINTENANCE IS REQUIRED TO
AVOID POTENTIAL HAZARDS WHICH GIVE A
RISK OF EXPLOSION

The responsibility for compliance with maintenance
instructions is with the plant operator.

To avoid potential explosion hazards during
maintenance, the tools, cleaning and painting
materials used must not give rise to sparking or
adversely affect the ambient conditions. Where there
is a risk from such tools or materials, maintenance
must be conducted in a safe area.

It is recommended that a maintenance plan and
schedule is adopted. (See section 6, Maintenance.)

Page 8 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

1.7 Nameplate and safety labels

1.7.1 Nameplate

For details of nameplate, see the Declaration of
Conformity, or separate documentation included with

these User Instructions.

1.7.2 Safety labels

Oil lubricated units only:

1.8 Specific machine performance

For performance parameters see section 1.5, Duty
conditions. Where performance data has been supplied

separately to the purchaser these should be obtained
and retained with these User Instructions.

1.9 Noise level

Attention must be given to the exposure of personnel
to the noise, and local legislation will define when
guidance to personnel on noise limitation is required,
and when noise exposure reduction is mandatory.
This is typically 80 to 85 dBA.

The usual approach is to control the exposure time to
the noise or to enclose the machine to reduce
emitted sound. You may have already specified a
limiting noise level when the equipment was ordered,
however if no noise requirements were defined, then
attention is drawn to the following table to give an
indication of equipment noise level so that you can
take the appropriate action in your plant.

Pump noise level is dependent on a number of
operational factors, flow rate, pipework design and
acoustic characteristics of the building, and so the
values given are subject to a 3 dBA tolerance and
cannot be guaranteed.

Similarly the motor noise assumed in the “pump and
motor” noise is that typically expected from standard

and high efficiency motors when on load directly driving
the pump. Note that a motor driven by an inverter may
show an increased noise at some speeds.

If a pump unit only has been purchased for fitting with

your own driver then the “pump only” noise levels in the

table should be combined with the level for the driver
obtained from the supplier. Consult Flowserve or a
noise specialist if assistance is required in combining
the values.

It is recommended that where exposure approaches
the prescribed limit, then site noise measurements
should be made.

The values are in sound pressure level LpA at 1 m

(3.3 ft) from the machine, for “free field conditions
over a reflecting plane”.

For estimating sound power level LWA (re 1 pW) then
add 14 dBA to the sound pressure value.

The values in below table are valid for preferred
range of pump operation, 80% to 110% of B.E.P.

Page 9 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Motor size
and speed

kW (hp)

Typical sound pressure level LpA at 1 m reference 20 μPa, dBA

3550 r/min

2900 r/min

1750 r/min

1450 r/min

Pump

only

Pump and

motor

Pump

only

Pump and

motor

Pump

only

Pump and

motor

Pump

only

Pump and

motor

<0.55 (<0.75)

58

65

50

58

50

52

50

52

0.75 (1)

60

65

52

59

51

54

51

54

1.1 (1.5)

62

67

54

60

55

57

53

56

1.5 (2)

63

66

55

63

56

59

54

58

2.2 (3)

64

69

57

65

58

62

56

60

3 (4)

63

71

58

68

59

64

57

62

4 (5)

64

72

60

69

61

65

59

63

5.5 (7.5)

66

73

62

71

63

67

61

65

7.5 (10)

67

73

63

71

64

69

62

67

11 (15)

69

76

65

73

66

71

64

69

15 (20)

71

77

67

74

68

72

66

70

18.5 (25)

72

78

68

75

69

70

67

70

22 (30)

73

78

69

76

70

71

68

71

30 (40)

75

79

71

77

72

72

70

72

37 (50)

76

80

72

78

73

73

71

73

45 (60)

77

81

73

79

74

74

72

74

55 (75)

78

81

74

79

75

75

73

75

75 (100)

80

83

76

81

77

76

75

76

90 (120)

81

84

77

81

78

77

76

77

110 (150)

82

85

78

82

79

78

77

78

150 (200)

84

87

80

84

81

79

79

79

200 (270)

① ① ①

①

81

81

79

79

300 (400)

–

83

86

81

82

 The noise level of machines in this range will most likely be of values which require noise exposure control, but typical values are inappropriate.
Note: for 1 180 and 960 r/min reduce 1 450 r/min values by 2 dBA. For 880 and 720 r/min reduce 1 450 r/min values by 3 dBA.

2 TRANSPORT AND STORAGE

2.3 Lifting

2.1 Consignment receipt and
unpacking

Immediately after receipt of the equipment it must be
checked against the delivery/shipping documents for
its completeness and that there has been no damage
in transportation. Any shortage and/or damage must
be reported immediately to Flowserve and must be
received in writing within one month of receipt of the
equipment. Later claims cannot be accepted.

Check any crate, boxes or wrappings for any
accessories or spare parts that may be packed

A crane must be used for all pump sets or
components in excess of 25 kg (55 lb.). Fully trained
personnel must carry out lifting, in accordance with
local regulations.

Slings, ropes and other lifting gear should be
positioned where they cannot slip and where a
balanced lift is obtained. The angle between sling or
ropes used for lifting must not exceed 60°.

2.3.1 Bare pump

The bare pump should be lifted as shown:

separately with the equipment or attached to side
walls of the box or equipment.

Each product has a unique serial number. Check
that this number corresponds with that advised and
always quote this number in correspondence as well
as when ordering spare parts or further accessories.

2.2 Handling

Boxes, crates, pallets or cartons may be unloaded
using fork lift vehicles or slings dependent on their
size and construction.

Page 10 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

2.3.2 Pump and folded steel or polycrete
baseplate set

Where the baseplate is folded steel or polycrete there
are no specific lifting points provided for the complete
machine set. Any lifting points that can be seen are
provided only for dismantling parts for servicing.

The pump and folded steel, or polycrete, baseplate set
should be lifted as shown. With a sling around the
pump discharge nozzle, and around the outboard end
of the motor frame using choker hitches pulled tight.
The sling should be positioned so the weight is not
carried through the motor fan housing. Make sure the
completion of the choker hitch on the discharge nozzle
is toward the coupling end of the pump.

2.3.3 Pump and cast iron or fabricated,
baseplate set

The pump and cast iron, or fabricated, baseplate set
which has specific lifting points, should be lifted as
shown:

Before lifting the driver alone, refer to the
manufacturer’s instructions.

2.4 Storage

Store the pump in a clean, dry location
away from vibration. Leave piping connection covers in
place to keep dirt and other foreign material out of pump
casing. Turn pump at intervals to prevent brinelling of
the bearings and the seal faces, if fitted, from sticking.

The pump may be stored as above for up to 6
months. Consult Flowserve for preservative actions
when a longer storage period is needed.

2.5 Recycling and end of product life

At the end of the service life of the product or its
parts, the relevant materials and parts should be
recycled or disposed of using an environmentally
acceptable method and local requirements. If the
product contains substances that are harmful to the
environment, these should be removed and disposed
of in accordance with current regulations. This also
includes the liquids and/or gases that may be used in
the "seal system" or other utilities.

Make sure that hazardous substances are
disposed of safely and that the correct personal
protective equipment is used. The safety
specifications must be in accordance with the current
regulations at all times.

3 DESCRIPTION

3.1 Configurations

The pump is a modular designed centrifugal pump
that can be built to achieve almost all chemical liquid
pumping requirements. (See 3.2 and 3.3 below.)

3.2 Name nomenclature

The pump size will be engraved on the nameplate
typically as below:

1K80-50-H200A-RV

 1 = ISO frame size (1, 2, 3, 4)
 K = Durco Mark 3 family
 80 = nominal suction size in mm
 50 = nominal discharge size in mm
 Configuration modifier:

Blank or no letter = standard frame mounted
P = self-priming casing
R = recessed impeller, low shear design
N = centerline mounted high pressure casing
H = foot mounted high pressure casing

 200 = nominal impeller diameter
 A = extended flow hydraulic (B = standard hydraulic)
 RV = impeller design

(RV = reverse vane, OP = open)

Page 11 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

The typical nomenclature above is the general guide
to the Durco Mark 3 ISO configuration description.
Identify the actual pump size and serial number from
the pump nameplate. Check that this agrees with the
applicable certification provided.

3.3 Design of major parts

3.3.1 Pump casing

The pump casing is designed with a horizontal
centerline end inlet and a vertical centerline top outlet
that makes it self-venting.

In addition, the P self-priming pump casing is
designed with a self-priming action which works on
the reflux principle for suction lifts up to 7 m (23 ft).

For ease of maintenance, the pump is constructed so
that pipe connectors do not have to be disturbed
when internal maintenance is required.

Casing feet pads are provided underneath the casing
except on the N casing where they are on the shaft
centerline.

3.3.2 Impeller

Depending on the product, the impeller is either reverse
vane or open. (On the R impeller it is recessed into
the back of the casing.)

Impeller locking 3.3.2.1

Most A-OP type impellers are available with the
option of key drive impeller. Most RV type impellers
are available with the option of an impeller locking
screw to provide an additional protection from
loosening of the impeller during a reverse run.

3.3.3 Shaft

The large diameter stiff shaft, mounted on bearings,
has a keyed drive end.

3.3.4 Bearing housing

The bearing housing enables adjustment of impeller
face clearance via the bearing carrier micrometer
mechanism.

3.3.5 Pump bearings and lubrication

The pump is fitted with ball and or roller type bearings
which may be configured differently dependent on
use. The bearings may be oil or grease lubricated.

3.3.6 Adaptor

The pump is fitted with an adaptor between bearing
housing and cover for optimum interchangeability.

3.3.7 Cover (seal chamber)

The cover has spigots between the pump casing and
bearing housing for optimum concentricity.

A fully confined gasket forms the seal between the
pump casing and the cover.

The cover designs provide improved performance of
mechanical seals.

The design enables one of a number of sealing
options to be fitted.

3.3.8 Shaft seal

The mechanical seal(s) attached to the drive shaft
seals the pumped liquid from the environment. Gland
packing may be fitted as an option, except on the P
self-primer casing.

3.3.9 Driver

The driver is normally an electric motor. Different drive
configurations may be fitted such as internal combustion
engines, turbines, hydraulic motors, and driving via
couplings, belts, gearboxes, drive shafts etc.

3.3.10 IPS Beacon

The pump is fitted with a temperature and vibration
monitor as standard. For additional information see
the IPS Beacon User Instructions (26999949) which
are supplied separately.

3.3.11 Accessories

Accessories may be fitted when specified by the
customer.

Fan cooling is available for high temperature operation.
(This is a fan fitted within the coupling guard to blow
cooling air over the bearing housing and shaft.)

3.4 Performance and operating limits

This product has been selected to meet the
specifications of the purchase order. See section 1.5.

The following data is included as additional
information to help with your installation. It is typical,
and factors such as temperature, materials, and seal
type may influence this data. If required, a definitive
statement for your particular application can be
obtained from Flowserve.

3.4.1 Operating limits

Normal maximum ambient temperature:

+40 ºC (104 ºF).

Normal minimum ambient temperature:

-20 ºC (-4 ºF).

Maximum pump speed: refer to the nameplate.

Page 12 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

3.4.2 Energy efficiency operation of pumps

The pump supplied will have been selected from

Flowserve’s extensive product line to have optimum

efficiency for the application. If supplied with an electric
motor then the motor will meet or exceed current
legislation for motor efficiency. However it is the way
the pump is operated which has the greatest impact on
the amount and cost of energy used during the
operating life of the pump. The following are key points
in achieving minimum operating cost for the equipment:

 Design the pipe system for minimum friction losses
 Ensure that the control system switches off the

pump when not required

 In a multi-pump system run the minimum number

of pumps

 Try to avoid systems which by-pass excess flow
 As far as possible avoid controlling pump flow by

using throttle valves

 When commissioned, check that the pump

operates at the duty specified to Flowserve

 If it has been found that the pump head and flow

exceed that required, trim the pump impeller
diameter

 Ensure that the pump is operating with sufficient

NPSH available

 Use variable speed drives for systems that

require variable flow. A VFD for an induction
motor is a particularly effective way of achieving
speed variation and energy/cost reduction

 Notes for VFD usage:

o make sure that the motor is compatible with

VFD

o Do not over-speed the pump without

checking the power capability with Flowserve

o On systems with high static head, speed

reduction is limited. Avoid running the pump
at a speed which gives low or zero flow

o Do not run a low speed and flow rate that lets

solids settle out of suspension in the pipework

o Do not use a VFD for a fixed flow requirement;

it will introduce power losses

 Select high efficiency motors
 If replacing a standard motor with a high

efficiency motor it will run faster and the pump
could take more power. Reduce the impeller
diameter to achieve energy reduction

 If the pump system pipework or equipment is

changed or process duty is changed, check that
the pump is still correctly sized

 Periodically check that the pipe system has not

become corroded or blocked

 Periodically check that the pump is operating at

the flow, head and power expected and that the
efficiency has not reduced with erosion or
corrosion damage

4 INSTALLATION

Equipment operated in hazardous locations
must comply with the relevant explosion protection
regulations. See section 1.6.4, Products used in

potentially explosive atmospheres.

4.1 Location

The pump should be located to allow room for access,
ventilation, maintenance and inspection with ample
headroom for lifting and should be as close as
practicable to the supply of liquid to be pumped. Refer
to the general arrangement drawing for the pump set.

4.2 Part assemblies

On baseplated pump sets the coupling elements are
supplied loose. It is the responsibility of the installer
to ensure that the pump set is finally lined up as
detailed in section 4.5.2, Alignment methods.

4.3 Foundation

There are many methods of installing

pump units to their foundations. The correct method
depends on the size of the pump unit, its location and
noise and vibration limitations. Non-compliance with
the provision of correct foundation and installation
may lead to failure of the pump and, as such, would
be outside the terms of the warranty.

Ensure the following are met:

a) The baseplate should be mounted onto a firm

foundation, either an appropriate thickness of
quality concrete or sturdy steel framework. (It
should NOT be distorted or pulled down onto the
surface of the foundation, but should be
supported to maintain the original alignment.)

b) Install the baseplate onto packing pieces evenly

spaced and adjacent to foundation bolts.

c) Level with shims between baseplate and packing

pieces.

Page 13 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Pa ralle l

An gu lar

d) The pump and driver have been aligned before

dispatch however the alignment of pump and motor
half coupling must be checked. If this is incorrect, it
indicates that the baseplate has become twisted
and should be corrected by re-shimming.

e) If not supplied, guarding shall be fitted as necessary

to meet the requirements of ISO 12100 and EN953.

4.4 Grouting

Where applicable, grout in the foundation bolts.
After adding pipework connections and rechecking the

coupling alignment, the baseplate should then be
grouted in accordance with good engineering practice.
Fabricated steel, folded steel and cast iron baseplates
can be filled with grout. Polycrete baseplates cannot be
grouted in the same way, see their User Instructions
71569284 (E) for installation and use. If in any doubt,
please contact your nearest service center for advice.

Grouting provides solid contact between the pump unit
and foundation, prevents lateral movement of vibrating
equipment and dampens resonant vibrations.

Foundation bolts should only be fully tightened when
the grout has cured.

4.5 Initial alignment

4.5.1 Thermal expansion

The pump and motor will normally have

to be aligned at ambient temperature with an allowance
for thermal expansion at operating temperature. In
pump installations involving high liquid temperatures,
typically above 100 ºC (212 ºF), the unit should be run
at the actual operating temperature, shut down and the
alignment checked immediately.

4.5.2 Alignment methods

move the pump before recommencing the above
procedure.

For couplings with narrow flanges use a dial indicator
as shown. The alignment values are maximums for
continuous service.

Permissible misalignment limits at working temperature:
 Parallel alignment

- 0.25 mm (0.010 in.) TIR maximum

 Angular alignment

- 0.3 mm (0.012 in.) TIR maximum for couplings
not exceeding 100 mm (4 in.) flange diameter

- 0.5 mm (0.020 in.) TIR maximum for couplings
over 100 mm (4 in.) diameter

When checking parallel alignment, the total indicator
read-out (TIR) shown is twice the value of the actual
shaft displacement.

Align in the vertical plane first, then horizontally by
moving motor. Maximum pump reliability is obtained
by near perfect alignment of 0.05 - 0.075 mm (0.002 -

0.003 in.) parallel and 0.05 mm (0.002 in.) per 100 mm
(4 in.) of coupling flange diameter as angular
misalignment.

4.5.3 Check for soft foot

Pump and driver must be isolated

electrically and the half couplings disconnected.

The alignment MUST be checked.

Although the pump will have been aligned at the
factory it is most likely that this alignment will have
been disturbed during transportation or handling. If
necessary, align the motor to the pump, not the pump
to the motor.

Alignment is achieved by adding or removing shims
under the motor feet and also moving the motor
horizontally as required. In some cases where the
alignment cannot be achieved it will be necessary to

This is a check to ensure that there is no undue stress
on the driver holding down bolts; due to non-level
baseplate or twisting. To check, remove all shims and
clean surfaces and tighten down driver to the baseplate.
Set a dial indicator as shown in sketch and loosen off
the holding down bolt while noting any deflection
reading on the dial test Indicator - a maximum of

0.05 mm (0.002 in.) is considered acceptable but any
more will have to be corrected by adding shims.

Page 14 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

For example, if the dial test indicator shows the foot
lifting 0.15 mm (0.006 in.) then this is the thickness of
shim to be placed under that foot. Tighten down and
repeat the same procedure on all other feet until all
are within tolerance.

Complete piping as below and see sections 4.8,

Final shaft alignment check, up to and including section
5, Commissioning, startup, operation and shutdown,
before connecting driver and checking actual rotation.

4.6 Piping

Protective covers are fitted to the pipe

connections to prevent foreign bodies entering during
transportation and installation. Ensure that these
covers are removed from the pump before connecting
any pipes.

4.6.1 Suction and discharge pipework

Never use pump as a support for piping.

Maximum forces and moments allowed on the pump
flanges vary with the pump size and type. To minimize
these forces and moments that may, if excessive, cause
misalignment, hot bearings, worn couplings, vibration
and the possible failure of the pump casing, the
following points should be strictly followed:

 Prevent excessive external pipe load
 Never draw piping into place by applying force to

pump flange connections

 Do not mount expansion joints so that their force,

due to internal pressure, acts on the pump flange

Ensure piping and fittings are flushed

before use.

Ensure piping for hazardous liquids is arranged

to allow pump flushing before removal of the pump.
Take into account the available NPSH which must be

higher than the required NPSH of the pump.

Non self-primer casings 4.6.1.1

In order to minimize friction losses and hydraulic
noise in the pipework it is good practice to choose
pipework that is one or two sizes larger than the
pump suction and discharge. Typically main
pipework velocities should not exceed 2 m/s (6 ft/sec)
suction and 3 m/s (9 ft/sec) on the discharge.

Self-priming casing 4.6.1.2

The delivery pipework must permit priming air to
escape unhindered from the pump during the priming

cycle, without back pressure and prevent excessive
run-back of liquid on shutdown to minimize syphoning.

Priming air may be vented in one of the following ways:

1) The discharge pipework regulating valve, if fitted,

may be partly opened during the priming cycle to
freely vent the air.

2) An automatic air release valve may be fitted to the

discharge pipework, between the pump and any
valves, providing that gases and vapors given off
are environmentally safe and acceptable for
release into the atmosphere.

3) An air bleed pipe may be run from the discharge

pipework, between the pump and any valves, back
to the suction tank or sump. This arrangement has a
disadvantage in that manual/automatic control will be
necessary during operation to prevent continuous re­circulation of the pumped liquid.

4.6.2 Suction piping

Non self-primer casing suction piping 4.6.2.1

a) The inlet pipe should be one or two sizes larger

than the pump inlet bore and pipe bends should
be as large a radius as possible.

b) On suction lift the piping should be inclined up

towards the pump inlet with eccentric reducers
incorporated to prevent air locks.

c) On positive suction, the inlet piping must have a

constant fall towards the pump.

d) The pipe next to the pump should be the same

diameter as the pump suction and have a minimum
of two pipe diameters of straight section between
the elbow and the pump inlet flange. Where the
NPSH margin is not large, it is recommended that
the pipe straight is 5 to 10 pipe diameter. (See
section 10.3, Reference 1.) Inlet strainers, when
used, should have a net 'free area' of at least three
times the inlet pipe area.

e) Fitting isolation and non-return valves will allow

easier maintenance.

f) Never throttle pump on suction side and never

place a valve directly on the pump inlet nozzle.

Self-priming casing suction piping 4.6.2.2

a) The inlet pipe should be as short as possible,

airtight and the smallest volume as practical for the
pump flow rate so as to be able to prime quickly.
Where inlet pipe volume is large an inlet ball-foot
valve or flap valve will be required.

b) It is recommended that the pump inlet pipe is no

larger than the pump inlet bore or such that the
suction velocity is in the range of 3 to 5 m/s
(10 to 16 ft/sec). The piping should slope down
towards the pump casing suction flange.

Page 15 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

c) Take into account the available NPSH, which must

be higher than the required NPSH of the pump.

d) Allow a minimum of two pipe diameters of straight

section between the elbow and inlet flange.

e) Fitting an isolation valve will allow easier

maintenance.

f) Never throttle pump on suction side and never

place a valve directly on the pump inlet nozzle.

Suction strainer 4.6.2.3

In a new installation, great care should be taken to
prevent dirt, scale, welding beads and other items
from entering the pump, as it is particularly important
to protect the numerous close running fits from
abrasive matter present in new piping.

The suction system should be thoroughly flushed
before installing the suction strainer and making up
suction piping to the pump.

The suction strainer should be installed between 5 to 20
pipe diameters upstream from the pump suction flange.

The open area of the strainer should

have a minimum of a 3 to 1 ratio to the area of the
pump suction.

Cone type strainer

The Flowserve recommendation for suction strainers
consists of a conical shaped steel plate. The plate
has 1.6 mm (1/16 in.) perforations and is of sufficient
size and thickness for the required flow. (See figure
above.)

Other type of strainers may be used as long as they
conform to the requirements stated above.

Pressure gauges should be installed on both sides of
the screen so that the pressure drop across the
screen can be measured.

When the unit is being started, the gauges on each
side of the screen should be carefully watched. An
increase in the differential pressure between the two
gauges indicates that the screen is becoming clogged
with dirt and scale. At this point, the pump should be
shut down, and the screen cleaned and or replaced.

A spool piece should be installed in

suction line so that the suction strainer may be
installed and removed with a pressure gauge
between the strainer and pump.

4.6.3 Discharge piping

Non self-primer casing discharge piping 4.6.3.1

a) A non-return valve should be located in the

discharge pipework to protect the pump from
excessive back pressure and hence reverse
rotation when the unit is stopped.

b) Fitting an isolation valve will allow easier

maintenance.

Self-priming casing discharge piping 4.6.3.2

a) In order to minimize friction losses and hydraulic

noise in the pipework it is good practice to choose
pipework that is one or two sizes larger than the
pump discharge. Typically main pipework velocities
should not exceed 3 m/s (9 ft/sec) on the discharge.
Pipework expanders should have a maximum angle
of divergence of 9 degrees.

b) If a non-return valve is located in the discharge

pipework then a vent/bleed pipe should be fitted
from the discharge pipe back to the sump or
source tank.

c) A regulating valve should be fitted in the discharge

pipework unless pump flow is controlled by the
delivery system design.

4.6.4 Allowable nozzle loads

The pump complies with ISO 5199 shaft deflection
limits for the following flange loads. The values are
presented in the ISO 5199/ISO 13709 (API 610)
format. Please note that the values permitted may be
higher or lower than those in ISO 5199; see those
specified for the actual pump size.

The values permitted (50 mm and above) meet ISO
13709 (API610 11th edition) Table 5 values with
grouted metallic baseplates. Individual forces and
moments up to twice ISO 13709 (API610) Table 5
values may be permitted but only when applied in
accordance with the conditions in ISO 13709
(API610) Annex F.

Values are presented in compliance with the ISO
1503 sign convention.

All individual values which are greater than the
following values must be referred to Flowserve for
approval.

Page 16 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Size

Forces in N (lbf)

Moments in Nm (lbf•ft)

Suction

Discharge

Suction

Discharge

Mx

My

Mz

Fx

Fy

Fz

Mx

My

Mz

Fx

Fy

Fz

ƩM

ƩF

ƩM

ƩF

40-25-125

840

(620)

450

(330)

640

(470)

1 800

(400)

1 500

(340)

1 200
(270)

190

(140)

180

(130)

190

(140)

460

(100)

370

(80)

580

(130)

1 150

(850)

2 630

(590)

320

(240)

830

(190)

50-32-125

930

(690)

470

(350)

700

(520)

1 780

(400)

1 430

(320)

1 160
(260)

340

(250)

170

(130)

260

(190)

520

(120)

430

(100)

660

(150)

1 260

(930)

2 560

(580)

460

(340)

940

(210)

65-40-125

1 640

(1 210)

820

(600)

1 230

(910)

2 300

(520)

1 840

(410)

1 500
(340)

560

(410)

280

(210)

420

(310)

860

(190)

700

(160)

1 070

(240)

2 210

(1 630)

3 310

(740)

750

(550)

1 540

(350)

80-50-125

1 910

(1 410

960

(710)

1 430

(1 050)

2 680

(600)

2 140

(480)

1 740
(390)

620

(460)

310

(230)

460

(340)

940

(210)

770

(170)

1 150

(260)

2 570

(1 900)

3 850

(870)

830

(610)

1 670

(380)

100-80-125

2 300

(1 700)

1 150

(850)

1 720

(1 270)

3 070

(690)

2 450

(550)

1 990
(450)

1 910

(1 410)

820

(600)

1 430

(1 050)

1 840

(410)

1 740

(390)

2 680

(600)

3 090

(2 280)

4 400

(990)

2 520

(1 860)

3 690

(830)

32-20-160

470

(350)

240

(160)

350

(260)

890

(200)

710

(160)

580

(130)

150

(110)

80

(60)

120

(90)

240

(50)

210

(50)

310

(70)

630

(460)

1 280

(290)

210

(150)

440

(100)

40-25-160

840

(620)

450

(330)

640

(470)

1 800

(400)

1 500

(340)

1 200
(270)

190

(140)

180

(130)

190

(140)

460

(100)

370

(80)

580

(130)

1 150

(850)

2 630

(590)

320

(240)

830

(190)

50-32-160

930

(690)

460

(340)

700

(520)

1 800

(400)

1 500

(340)

1 200
(270)

290

(210)

210

(150)

220

(160)

500

(110)

400

(90)

590

(130)

1 250

(920)

2 630

(590)

420

(310)

870

(200)

65-40-160

1 640

(1 210)

820

(600)

1 230

(910)

2 300

(520)

1 840

(410)

1 500
(340)

560

(410)

280

(210)

420

(310)

860

(190)

700

(160)

1 070

(240)

2 210

(1 630)

3 310

(740)

750

(550)

1 540

(350)

80-50-160

1 910

(1 410)

960

(710)

1 430

(1 050)

2 680

(600)

2 140

(480)

1 740
(390)

620

(460)

310

(230)

460

(340)

940

(210)

770

(170)

1 150

(260)

2 570

(1 900)

3 850

(870)

830

(610)

1 670

(380)

100-65-160

2 670

(1 970)

1 340

(990)

2 000

(1 480)

3 570

(800)

2 850

(640)

2 320
(520)

980

(720)

490

(360)

730

(540)

1 090

(250)

890

(200)

1 370

(310)

3 600

(2 660)

5 120

(1 150)

1 320
(970)

1 960

(440)

125-80-160

4 050

(2 990)

2 030

(1 500)

3 040

(2 240)

5 400

(1 210)

4 320

(970)

3 510
(790)

1 310

(970)

710

(520)

1 010

(740)

1 850

(420)

1 500

(340)

2 300

(520)

5 460

(4 030)

7 760

(1 740)

1 800

(1 330)

3 310

(740)

125-100-160

4 050

(2 990)

2 030

(1 500)

3 040

(2 240)

5 400

(1 210)

4 320

(970)

3 510
(790)

2 300

(1 700)

1 150

(850)

1 720

(1 270)

2 450

(550)

1 990

(450)

3 070

(690)

5 460

(4 030)

7 760

(1 740)

3 090

(2 280)

4 400

(990)

32-20-200

470

(350)

340

(250)

350

(260)

890

(200)

710

(160)

580

(130)

150

(110)

80

(60)

120

(90)

240

(50)

210

(50)

310

(70)

680

(500)

1 280

(290)

210

(150)

440

(100)

40-25-200

840

(620)

450

(330)

640

(470)

1 800

(400)

1 500

(340)

1 200
(270)

190

(140)

180

(130)

190

(140)

460

(100)

370

(80)

580

(130)

1 150

(850)

2 630

(590)

320

(240)

830

(190)

50-32-200

930

(690)

470

(350)

700

(520)

1 800

(400)

1 500

(340)

1 200
(270)

290

(210)

210

(150)

220

(160)

500

(110)

400

(90)

590

(130)

1 260

(930)

2 630

(590)

420

(310)

870

(200)

65-40-200

1 790

(1 320)

860

(630)

1 220

(900)

2 680

(600)

2 140

(480)

1 740
(390)

460

(340)

230

(170)

350

(260)

710

(160)

570

(130)

880

(200)

2 330

(1 720)

3 850

(870)

620

(460)

1 270

(290)

80-50-200

1 910

(1 410)

960

(710)

1 430

(1 050)

2 680

(600)

2 140

(480)

1 740
(390)

620

(460)

310

(230)

460

(340)

940

(210)

770

(170)

1 150

(260)

2 570

(1 900)

3 850

(870)

830

(610)

1 670

(380)

100-65-200

2 670

(1 970)

1 340

(990)

2 000

(1 480)

3 570

(800)

2 850

(640)

2 320
(520)

1 210

(890)

600

(440)

900

(660)

1 350

(300)

1 100

(250)

1 690

(380)

3 600

(2 660)

5 120

(1 150)

1 620

(1 190)

2 430

(550)

125-80-200

4 710

(3 470)

1 560

(1 150)

3 540

(2 610)

4 140

(930)

5 020

(1 130)

2 690
(600)

1 310

(970)

710

(520)

1 010

(740)

1 850

(420)

1 500

(340)

2 300

(520)

6 100

(4 500)

7 040

(1 580)

1 800

(1 330)

3 310

(740)

125-100-200

4 710

(3 470)

1 560

(1 150)

3 540

(2 610)

4 140

(930)

5 020

(1 130)

2 690
(600)

2 670

(1 970)

880

(650)

2 000

(1 480)

1 880

(420)

2 320

(520)

3 570

(800)

6 100

(4 500)

7 040

(1 580)

3 450

(2 540)

4 650

(1 050)

Table of maximum forces and moments (acting simultaneously) 4.6.4.1

Page 17 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Size

Forces in N (lbf)

Moments in Nm (lbf•ft)

Suction

Discharge

Suction

Discharge

Mx

My

Mz

Fx

Fy

Fz

Mx

My

Mz

Fx

Fy

Fz

ƩM

ƩF

ƩM

ƩF

40-25-250

840

(620)

450

(330)

640

(470)

1 800

(400)

1 500

(340)

1 200
(270)

190

(140)

180

(130)

190

(140)

450

(100)

370

(80)

540

(120)

1 150

(850)

2 630

(590)

320

(240)

790

(180)

50-32-250

930

(690)

460

(340)

700

(520)

1 800

(400)

1 500

(340)

1 200
(270)

290

(210)

210

(150)

220

(160)

500

(110)

370

(80)

590

(130)

1 250

(920)

2 630

(590)

420

(310)

860

(190)

65-40-250

1 780

(1 310)

860

(630)

1 220

(900)

2 680

(600)

2 140

(480)

1 740
(390)

500

(370)

260

(190)

370

(270)

750

(170)

610

(140)

940

(210)

2 320

(1 710)

3 850

(870)

670

(490)

1 350

(300)

80-50-250

1 910

(1 410)

960

(710)

1 430

(1 050)

2 680

(600)

2 140

(480)

1 740
(390)

720

(530)

360

(270)

540

(400)

1 100

(250)

890

(200)

1 370

(310)

2 570

(1 900)

3 850

(870)

970

(720)

1 970

(440)

100-65-250

2 670

(1 970)

1 340

(990)

2 000

(1 480)

3 570

(800)

2 850

(640)

2 320
(520)

1 150

(850)

570

(420)

860

(630)

1 290

(290)

1 040

(230)

1 610

(360)

3 600

(2 660)

5 120

(1 150)

1 540

(1 140)

2 310

(520)

125-80-250

4 710

(3 470)

1 860

(1 370)

3 540

(2 610)

4 960

(1 120)

5 020

(1 130)

3 220
(720)

1 310

(970)

710

(520)

1 010

(740)

1 850

(420)

1 500

(340)

2 300

(520)

6 100

(4 500)

7 040

(1 580)

1 800

(1 330)

3 310

(740)

125-100-250

4 710

(3 470)

1 860

(1 370)

3 540

(2 610)

4 960

(1 120)

5 020

(1 130)

3 220
(720)

2 670

(1 970)

1 060

(780)

2 000

(1 480)

1 880

(420)

2 320

(520)

3 570

(800)

6 180

(4 560)

7 760

(1 740)

3 500

(2 580)

4 650

(1 050)

150-125-250

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

4 960

(1 120)

5 020

(1 130)

3 220
(720)

4 710

(3 470)

1 340

(990)

3 540

(2 610)

2 860

(640)

4 090

(920)

6 280

(1 410)

6 350

(4 680)

7 760

(1 740)

6 040

(4 460)

8 020

(1 800)

200-150-250

6 990

(5 160)

3 500

(2 580)

5 240

(3 870)

9 460

(2 130)

7 560

(1 700)

6 150

(1 380)

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

5 020

(1 130)

4 080

(920)

6 280

(1 410)

9 410

(6 940)

13 580
(3 050)

6 350

(4 680)

9 020

(2 030)

50-32-315

930

(690)

470

(350)

700

(520)

1 800

(400)

1 500

(340)

1 200
(270)

460

(340)

230

(170)

350

(260)

720

(160)

580

(130)

890

(200)

1 260

(930)

2 630

(590)

620

(460)

1 280

(290)

65-40-315

1 510

(1 110)

840

(620)

1 030

(760)

2 580

(580)

1 940

(440)

1 740
(390)

580

(430)

290

(210)

400

(300)

900

(200)

730

(160)

1 120

(250)

2 010

(1 480)

3 670

(860)

760

(560)

1 610

(360)

80-50-315

1 910

(1 410)

960

(710)

1 430

(1 050)

2 680

(600)

2 140

(480)

1 740
(390)

720

(530)

360

(270)

540

(400)

1 100

(250)

890

(200)

1 370

(310)

2 570

(1 900)

3 850

(870)

970

(720)

1 970

(440)

100-65-315

2 670

(1 970)

1 340

(990)

2 000

(1 480)

3 570

(800)

2 850

(640)

2 320
(520)

1 640

(1 210)

820

(600)

1 230

(910)

1 840

(410)

1 490

(330)

2 300

(520)

3 600

(2 660)

5 120

(1 150)

2 210

(1 630)

3 300

(740)

125-80-315

4 710

(3 470)

1 740

(1 280)

3 540

(2 610)

4 650

(1 050)

5 020

(1 130)

3 020
(680)

2 670

(1 970)

990

(730)

2 000

(1 480)

2 110

(470)

2 320

(520)

3 570

(800)

6 140

(4 530)

7 480

(1 680)

3 480

(2 570)

4 750

(1 070)

125-100-315

4 710

(3 470)

1 740

(1 280)

3 540

(2 610)

4 650

(1 050)

5 020

(1 130)

3 020
(680)

2 670

(1 970)

1 060

(780)

2 000

(1 480)

1 880

(420)

2 320

(520)

3 570

(800)

6 140

(4 530)

7 480

(1 680)

3 500

(2 580)

4 650

(1 050)

150-125-315

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

6 280

(1 410)

5 020

(1 130)

4 080
(920)

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

5 020

(1 130)

4 090

(920)

6 280

(1 410)

6 350

(4 680)

9 020

(2 030)

6 350

(4 680)

9 020

(2 030)

200-150-315

6 990

(5 160)

3 500

(2 580)

5 240

(3 870)

9 460

(2 130)

7 550

(1 700)

6 150

(1 380)

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

5 020

(1 130)

4 090

(920)

6 280

(1 410)

9 410

(6 940)

13 580
(3 050)

6 350

(4 680)

9 020

(2 030)

100-65-400

2 670

(1 970)

1 340

(990)

2 000

(1 480)

3 570

(800)

2 850

(640)

2 320
(520)

1 210

(890)

600

(440)

900

(660)

1 350

(300)

1 100

(250)

1 690

(380)

3 600

(2 660)

5 120

(1 150)

1 620

(1 190)

2 430

(550)

125-80-400

4 710

(3 470)

1 740

(1 280)

3 540

(2 610)

4 650

(1 050)

5 020

(1 130)

3 020
(680)

1 310

(970)

710

(520)

1 010

(740)

1 850

(420)

1 500

(340)

2 300

(520)

6 140

(4 530)

7 480

(1 680)

1 800

(1 330)

3 310

(740)

125-100-400

4 710

(3 470)

1 740

(1 280)

3 540

(2 610)

4 650

(1 050)

5 020

(1 130)

3 020
(680)

2 670

(1 970)

1 060

(780)

2 000

(1 480)

1 880

(420)

2 320

(520)

3 570

(800)

6 140

(4 530)

7 480

(1 680)

3 500

(2 580)

4 650

(1 050)

150-125-400

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

6 280

(1 410)

5 020

(1 130)

4 080
(920)

2 670

(1 970)

990

(730)

2 000

(1 480)

2 110

(470)

2 320

(520)

3 570

(800)

6 350

(4 680)

9 020

(2 030)

3 480

(2 570)

4 750

(1 070)

200-150-400

6 990

(5 160)

3 500

(2 580)

5 240

(3 870)

9 460

(2 130)

7 550

(1 700)

6 150

(1 380)

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

5 020

(1 130)

4 090

(920)

6 280

(1 410)

9 410

(6 940)

13 580
(3 050)

6 350

(4 680)

9 020

(2 030)

250-200-400

9 950

(7 340)

4 980

(3 670)

7 460

(5 500)

13 420

(3 020)

10 730

(2 410)

8 720

(1 960)

6 990

(5 160)

3 500

(2 580)

5 240

(3 870)

7 560

(1 700)

6 150

(1 380)

9 460

(2 130)

13 400

(9 880)

19 270
(4 330)

9 410

(6 940)

13 580

(3 050)

200-150-500

6 990

(5 160)

3 500

(2 580)

5 240

(3 870)

9 460

(2 130)

7 550

(1 700)

6 150

(1 380)

4 710

(3 470)

2 360

(1 740)

3 540

(2 610)

5 020

(1 130)

4 090

(920)

6 280

(1 410)

9 410

(6 940)

13 580
(3 050)

6 350

(4 680)

9 020

(2 030)

Casing material

Liquid temperature ºC (ºF)

-20 to 100

(-4 to 212)

101 to 200

(213 to 392)

201 to 299

(393 to 570)

300 to 350

(571 to 662)

350 to 400

(663 to 752)

Austenitic ductile iron, Alloy 20,

Titanium, Titanium Pd

0.8

0.76

0.72

0.68

0.64

Nickel

0.5

0.475

0.45

0.425

0.40

All other materials

1.0

0.95

0.9

0.85

0.80

The values in the table above must be multiplied by the following factors.

Page 18 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

4.6.5 Final checks

Check the tightness of all bolts in the suction and
discharge pipework. Check also the tightness of all
foundation bolts.

4.6.6 Auxiliary piping

The connections that are to be piped up

will have been fitted with protective metal or plastic
plugs which will need to be removed.

Pumps fitted with packed glands 4.6.6.1

When suction pressure is below ambient pressure and
differential head is less than 10 m (32.8 ft), it may be
necessary to feed gland packing with liquid to provide
lubrication and prevent the ingress of air.

Pumps fitted with mechanical seals 4.6.6.2

The Seal Sentry design of the anti-vortex chamber for
single internal seals provides excellent liquid circulation
around the seal and will not normally require a separate
flush.

Single seals requiring re-circulation will normally be
provided with the auxiliary piping from pump casing
already fitted.

Flowserve seal connections are designated as follows:

Q - quench
F - flush
D - drain outlet
BI - barrier fluid in (double seals)
BO - barrier fluid out (double seals)
H - heating jacket
C - cooling jacket

Seal chambers/covers having an auxiliary quench
connection, require connection to a suitable source of
liquid flow, low pressure steam or static pressure from a
header tank. Recommended pressure is 0.35 bar
(5 psi) or less. Check General arrangement drawing.

Double seals require a barrier liquid between the seals,
compatible with the pumped liquid.

With back-to-back double seals, the barrier liquid
should be at a minimum pressure of 1 bar (14.5 psi)
above the maximum pressure on the pump side of the
inner seal (see appropriate chart). The barrier liquid
pressure must not exceed limitations of the seal on the
atmospheric side. For toxic service the barrier liquid
supply and discharge must be handled safely and in
line with local legislation

It is important to understand the pressure at the rear of
the impeller and in the seal chamber, to have reliable
seals. Consult Flowserve or the seal manufacturer for
guidance if required.

Open impellers (OP) generated rear pressure:

Reverse vane impellers (RV) generated rear pressure:

Notes:

Differential pressure in bar = Head in meters x specific gravity

10.19
a) Total seal pressure is equal to the sum of pressure at seal (from

the applicable chart above) plus suction pressure.

b) Ensure to check the seal minimum and maximum pressure limits

are not exceeded.

Special seals may require modification to auxiliary
piping described above. Consult Flowserve if unsure of
correct method or arrangement. For pumping hot
liquids, to avoid seal damage, it is recommended that
any external flush/cooling supply be continued after
stopping the pump. Dual seals require a barrier liquid
between the seals compatible with the pumped liquid.

Pumps fitted with heating/cooling jackets 4.6.6.3

Connect the heating/cooling pipes from the site supply.
The top connection should be used as the outlet to
ensure complete filling/venting of the annulus with
heating/cooling liquids; steam is usually in at the top,
out at the bottom.

Page 19 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

4.7 Electrical connections

Electrical connections must be made by a

qualified Electrician in accordance with relevant local
national and international regulations.

It is important to be aware of the EUROPEAN

DIRECTIVE on potentially explosive areas where
compliance with IEC60079-14 is an additional
requirement for making electrical connections.

It is important to be aware of the EUROPEAN
DIRECTIVE on electromagnetic compatibility when
wiring up and installing equipment on site. Attention
must be paid to ensure that the techniques used during
wiring/installation do not increase electromagnetic
emissions or decrease the electromagnetic immunity of
the equipment, wiring or any connected devices. If in
any doubt contact Flowserve for advice.

The motor must be wired up in

accordance with the motor manufacturer's instructions
(normally supplied within the terminal box) including
any temperature, earth leakage, current and other
protective devices as appropriate. The identification
nameplate should be checked to ensure the power
supply is appropriate.

A device to provide emergency stopping must be
fitted.

If not supplied pre-wired to the pump unit, the
controller/starter electrical details will also be supplied
within the controller/starter.

For electrical details on pump sets with controllers see
the separate wiring diagram.

If there is any possibility of the system allowing the
pump to run against a closed valve or below minimum
continuous safe flow a protection device should be
installed to ensure the temperature of the liquid does
not rise to an unsafe level.

If there are any circumstances in which the system can
allow the pump to run dry, or start up empty, a power
monitor should be fitted to stop the pump or prevent it
from being started. This is particularly relevant if the
pump is handling a flammable liquid.

If leakage of product from the pump or its associated
sealing system can cause a hazard it is recommended
that an appropriate leakage detection system is
installed.

To prevent excessive surface temperatures at bearings
it is recommended that temperature or vibration
monitoring is carried out. The IPS Beacon with a local
display is fitted as standard. When a centralized
control system is required it will be necessary to
replace the IPS Beacon with appropriate temperature
and/or vibration probes.

5 COMMISSIONING, START-UP,
OPERATION AND SHUTDOWN

These operations must be carried out

by fully qualified personnel.

5.1 Pre-commissioning procedure

5.1.1 Lubrication

Determine the mode of lubrication of the pump set,
e.g. grease, oil.

See section 5.4, Direction of rotation

before connecting the motor to the electrical supply.

4.8 Final shaft alignment check

After connecting piping to the pump, rotate the shaft
several times by hand to ensure there is no binding and
all parts are free. Recheck the coupling alignment, as
previously described, to ensure no pipe strain. If pipe
strain exists, correct piping.

housing [3200] with correct grade of oil to the correct
level, i.e. by use of the sight glass [3856] or constant
level oiler bottle [3855].

For oil lubricated pumps, fill the bearing

4.9 Protection systems

The following protection systems are
recommended particularly if the pump is installed in a
potentially explosive area or is handling a hazardous
liquid. If in any doubt consult Flowserve.

Page 20 of 52 flowserve.com

When fitted with a constant level oiler [3855], the bearing
housing [3200] should be filled by unscrewing or hinging
back the transparent bottle and filling it with oil. The
standard Adams oilers and the Trico Watchdog oilers are
self-setting and internally vent balanced.

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Frame size

Grease lubricated

medium duty bearings

Grease lubricated

heavy duty bearings

Grease lubricated bearing capacities

g (oz.)

Pump end

Drive end

Pump end

Drive end *

Pump end

Drive end

1
2
3
4

6207 Z C3
6309 Z C3

6311 Z C3

6313 Z C3

3306 Z C3
3309 Z C3
3311 Z C3
3313 Z C3

6207 Z C3
6309 Z C3
6311 Z C3
6313 Z C3

7306 pair back-to-back
7309 pair back-to-back
7311 pair back-to-back
7313 pair back-to-back

6 (0.2.)
13 (0.5)
18 (0.6)
20 (0.7)

14 (0.5)
25 (0.9)
35 (1.2)
46 (1.6)

Centrifugal

pump lubrication

Oil

Splash / force feed / purge and pure **oil mist lubrication

Viscosity cSt @ 40 ºC

32

46

68

Oil temperature range *

-5 to 65 ºC

(23 to 149 ºF)

-5 to 78 ºC

(23 to 172 ºF)

-5 to 80 ºC

(23 to 176 ºF)

Designation to ISO 3448 and DIN51524 part 2

ISO VG 32

32 HLP

ISO VG 46

46 HLP

ISO VG 68

68 HLP

Oil companies and lubricants

BP Castrol †

Energol HLP-HM 32

Energol HLP-HM 46

Energol HLP-HM 68

ESSO †

NUTO HP 32

NUTO HP 46

NUTO HP 68

ELF/Total †

ELFOLNA DS 32

Azolla ZS 32

ELFOLNA DS 46

Azolla ZS 46

ELFOLNA DS 68

Azolla ZS 68

LSC (for oil mist only – long life) †

LSO 32 (synthetic oil)

LSO 46 (synthetic oil)

LSO 68 (synthetic oil)

ExxonMobil (mineral oil) †

Mobil DTE 24

Mobil DTE 25

Mobil DTE 26

ExxonMobil (oil bath only – long life) †

Mobil SHC524

(synthetic oil) ***

Mobil SHC525

(synthetic oil)

Mobil SHC526

(synthetic oil)

Q8 †

Q8 Haydn 32

Q8 Haydn 46

Q8 Haydn 68

Shell †

Shell Tellus 32

Shell Tellus 46

Shell Tellus 68

Chevron Texaco †

Rando HD 32

Rando HD 46

Rando HD 68

Wintershall (BASF Group) †

Wiolan HS32

Wiolan HS46

Wiolan HS68

Fuchs †

Renolin CL 32

Renolin CL 46

Renolin CL 68

Where an adjustable body Denco oiler is fitted this should
be set to the height shown in the following diagram.

The oil filled bottle should then be refitted so as to
return it to the upright position.

Filling should be repeated until oil remains visible within
the bottle. Approximate oil volumes are shown in
section 5.2.2, Bearing sizes and capacities.

5.2 Pump lubricants

5.2.1 Recommended oil lubricants

Grease lubricated pumps and electric motors are
supplied pre-greased.

Where the ambient temperature is very low, special
lubricants are required. Where oil lubrication is utilized
and the ambient is less than -5 °C (23 °F) ensure the oil

pour point is at least 15 °C (27 °F) lower than the
ambient, or use oil class SAE 5W-50 or API-SJ and
ensure the upper operating range of the oil is then not
exceeded. IS0 VG 46 oil is generally selected for an
initial lubrication schedule.

Other drivers and gearboxes, if appropriate, should be
lubricated in accordance with their manuals.

* Note that it normally takes 2 hours for bearing temperature to stabilize and the final temperature will depend on the ambient, r/min, pumpage

temperature and pump size. Also some oils have a very low pour point and good viscosity index which extend the minimum temperature capability
of the oil. Always check the grade capability where the ambient is less than -5 ºC (23 ºF).

** If preheated pure oil mist lubrication, LCS LSO 68 or LSO 100 synthetic oils are permitted.

†

Use LSC for oil mist. Oil parameters provide flash point >166 ºC (331 ºF), density >0.87@15 ºC (59 ºF), pour point of -10 ºC (14 ºF) or lower.

*** ExxonMobil SHC 524 synthetic oil has a pour point temperature of -54 ºC. This oil can be used for ambient temperature as low as -50 ºC.

5.2.2 Bearing sizes and capacities

* Nilos ring fitted into bearing locknut [3712.2]

Page 21 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Frame size

Oil lubricated

medium duty bearings

Oil lubricated

heavy duty bearings

Oil lubricated optional

heavy duty bearings

Frame oil capacity

(approx.) *
litre (fl.oz)

Pump end

Drive end

Pump end

Drive end

Pump end

Drive end

1
2
3
4

6207 C3
6309 C3

6311 C3

6313 C3

3306 C3
3309 C3
3311 C3
3313 C3

6207 C3
6309 C3
6311 C3
6313 C3

7306 back-to-back
7309 back-to-back

7311 back-to-back

7313 back-to-back

NUP 207 C3
NUP 309 C3

NUP 311 C3

NUP 313 C3

7306 back-to-back
7309 back-to-back

7311 back-to-back

7313 back-to-back

0.5 (17)

1.0 (34)

0.8 (27)

1.6 (54)

Note: the bearing sizes do not constitute a purchasing specification.
* Sump volume only, does not include the oil in the constant level oiler.

5.2.3 Recommended grease lubricants

NLGI grade 2 is generally advised for horizontal bearing
housings and NLGI 3 where the bearing housing is used
vertically. The bearings are pre-greased. The NLGI 2
grade fitted in the factory with grease nipples is Mobil
Polyrex EM grease which has a Polyurea soap
incorporating a mineral oil. NLGI 3 grade is
recommended for vertical applications, if vertical
orientation was specified with order, then the NLGI 3
grease fitted in the factory for vertical application is Mobil
Polyrex EM103 grease or equivalent which has a
Polyurea soap incorporating a mineral oil. These greases
are suitable for high bearing and ambient temperatures
and ambient down to at least -20 °C. Below this ambient,
specialist greases may be required and Shell Aeroshell 22
is normally required for the minimum ambient down to
nitrile limitation of -45 °C.

Different types or grades of greases must

never be mixed.

Food grade grease, when applicable 5.2.3.1

NSF H1 Klubersynth UH1 64-62 is the food grade
grease option and it is NLGI grade 2.

5.2.4 Recommended fill quantities

Refer to section 5.2.2, Bearing sizes and capacities.

5.2.5 Lubrication schedule

Refer to section 6.2.3.

5.3 Impeller clearance

The impeller clearance is set in the factory. The
clearance may require adjustment because of high
liquid temperature. If piping attachment alters the
impeller clearance then correct piping. For setting
instructions see section 6.7, Setting impeller clearance.

5.4 Direction of rotation

Serious damage can result if the pump is

started or run in the wrong direction of rotation.

The pump is shipped with the coupling element removed.
Ensure the direction of rotation of the motor is correct
before fitting the coupling element. Direction of rotation
must correspond to the direction arrow.

If maintenance work has been carried

out to the site's electricity supply, the direction of
rotation should be re-checked as above in case the
supply phasing has been altered.

5.5 Guarding

Guarding is supplied fitted to the pump set.

In member countries of the EU and EFTA, it is a legal
requirement that fasteners for guards must remain
captive in the guard to comply with the Machinery
Directive 2006/42/EC. When releasing such guards,
the fasteners must be unscrewed in an appropriate way
to ensure that the fasteners remain captive.

Whenever guarding is removed or disturbed ensure that
all the protective guards are securely refitted prior to
start-up.

5.6 Priming and auxiliary supplies

5.6.1 Filling and priming, non self-primer casing

Ensure inlet pipe and pump casing is

completely full of liquid before starting continuous duty
operation.

Priming may be carried out with an ejector, vacuum
pump, interceptor or other equipment, or by flooding
from the inlet source.

When in service, pumps using inlet pipes with foot
valves may be primed by passing liquid back from the
outlet pipe through the pump.

5.6.2 Filling and priming, self-priming casing

Fill the pump with liquid to be pumped, or

compatible liquid, via the filling hole, before starting
continuous duty operation. The pump has self-priming
action for which a separate air pump is not normally
required.

Page 22 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Pump housing
filling hole.

When the initial fill
reaches the suction
pipe, excess liquid will
flow out of the casing.

Pump size

Initial fill litre (US gal.)

40-40-125

2.5 (0.65)

80-80-125

6.0 (1.60)

40-40-160

3.0 (0.80)

80-80-160

6.5 (1.75)

40-40-200

5.0 (1.30)

65-65-200

8.5 (2.25)

80-80-250

12.0 (3.20)

d) Prime the pump. (See section

5.6.2.) The pump casing must initially be filled with
compatible liquid before starting the unit.

e) Damage will occur if the pump is run dry or for

prolonged periods with no incoming liquid.

f) Subsequent filling should not be necessary unless the

pump has been emptied or drained of fluid.

g) Start the motor and, if no specific provision has been

made in the delivery pipework for evacuating the
primed air, open the delivery valve by approximately

10 % to allow priming air to escape.
h) When the pump has primed, check outlet pressure.
i) If the pressure is satisfactory, SLOWLY open the

outlet valve.
j) It is recommended that the priming time is noted.

Priming times in excess of 5 minutes will indicate a

pump or system fault. Any noticeable increases in

priming time on subsequent starts will also indicate

a fault. Irregular use could lead to the risk of

'evaporation' of the priming fluid.

5.6.3 Auxiliary supplies

pneumatic, sealant and lubrication systems (as
applicable) are connected and operational.

5.7 Starting the pump

5.7.1 Starting the non self-primer casing pump

a) Ensure flushing and/or cooling/

heating liquid supplies are turned ON, before
starting pump.

b) CLOSE the outlet valve.
c) OPEN all inlet valves.
d) Prime the pump, ensure the air within the pump has

a route to escape.
e) Start motor and check the outlet pressure.
f) If the pressure is satisfactory, SLOWLY open the

outlet valve.
g) Do not run the pump with the outlet

valve closed for a period longer than 10 seconds.
h) If NO pressure, or LOW pressure, STOP the pump.

Refer to section 7, Faults; causes and remedies, for

fault diagnosis.

5.7.2 Starting the self-priming casing pump

a) Ensure flushing and/or cooling/

heating liquid supplies are turned ON, before

starting pump.
b) CLOSE the outlet valve.
c) OPEN all inlet valves.

Page 23 of 52 flowserve.com

Ensure all electrical, hydraulic,

k) Do not run the pump with the outlet

valve closed for a period longer than 30 seconds.

l) If the pump has to fill the system it may take a short

time before the outlet is pressurized.

m) If NO pressure, or LOW pressure, STOP the pump.

Refer to section 7, Faults; causes and remedies for
fault diagnosis.

5.8 Running the pump

5.8.1 Pumps fitted with packed gland

If the pump has a packed gland there must be some
leakage from the gland. Gland nuts should initially be
finger-tight only. Leakage should take place soon after
the stuffing box is pressurized.

The gland must be adjusted evenly to give visible
leakage and concentric alignment of the gland ring to
avoid excess temperature. If no leakage takes place
the packing will begin to overheat. If overheating takes
place the pump should be stopped and allowed to cool
before being re-started. When the pump is re-started,
check to ensure leakage is taking place at the packed
gland.

If hot liquids are being pumped it may be necessary to
slacken the gland nuts to achieve leakage.

The pump should be run for 30 minutes with steady
leakage and the gland nuts tightened by 10 degrees at a
time until leakage is reduced to an acceptable level,
normally 30 to 120 drops per minute. Bedding in of the
packing may take another 30 minutes.

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Vibration velocity –

unfiltered

Horizontal pumps

 15 kW (20 hp)

Horizontal pumps

> 15 kW (20 hp)

mm/s (in./sec) r.m.s.

Normal N

 3.0 (0.12)

 4.5 (0.18)

Alarm N x 1.25

 3.8 (0.15)

 5.6 (0.22)

Shutdown trip N x 2.0

 6.0 (0.24)

 9.0 (0.35)

Vibration velocity

– unfiltered

Vertical configurations

mm/s (in./sec) r.m.s.

Normal N

 7.1 (0.28)

Alarm N x 1.25

 9.0 (0.35)

Shutdown trip N x 2.0

 14.2 (0.56)

Motor rating kW (hp)

Maximum stop/starts

per hour

Up to 15 (20)

15

Between 15 (20) and 90 (120)

10

Above 90 (120)

6

Care must be taken when adjusting the gland on
an operating pump. Safety gloves are essential. Loose
clothing must not be worn to avoid being caught up by
the pump shaft. Shaft guards must be replaced after
the gland adjustment is complete.

Never run gland packing dry, even for a

short time.

5.8.2 Pumps fitted with mechanical seal

Mechanical seals require no adjustment. Any slight initial
leakage will stop when the seal is run in.

Before pumping dirty liquids it is advisable, if possible, to
run the pump in using clean liquid to safeguard the seal
face.

External flush or quench should be started

before the pump is run and allowed to flow for a period
after the pump has stopped.

Never run a mechanical seal dry, even

for a short time.

5.8.3 Bearings

If the pumps are working in a potentially explosive
atmosphere temperature or vibration monitoring at the
bearings is recommended.

If bearing temperatures are to be monitored it is
essential that a benchmark temperature is recorded at
the commissioning stage and after the bearing
temperature has stabilized.
 Record the bearing temperature (t) and the ambient

temperature (ta)

 Estimate the likely maximum ambient temperature (tb)
 Set the alarm at (t+tb-ta+5) ºC (t+tb-ta+10) ºF and the

trip at 100 ºC (212 ºF) for oil lubrication and 105 ºC
(220 ºF) for grease lubrication

It is important, particularly with grease lubrication, to
keep a check on bearing temperatures. After start up
the temperature rise should be gradual, reaching a
maximum after approximately 1.5 to 2 hours. This
temperature should then remain constant or marginally
reduce with time. Refer to section 6.2.3.2 for further
information.

5.8.4 Normal vibration levels, alarm and trip

For guidance, pumps generally fall under a classification
for rigid support machines within the International rotating
machinery standards and the recommended maximum
levels below are based on those standards.

Alarm and trip values for installed pumps
should be based on the actual measurements (N) taken
on the pump in the fully commissioned as new
condition. Measuring vibration at regular intervals will
then show any deterioration in pump or system
operating conditions.

Where a grease lubricated unit is utilized in a vertical
shaft configuration with a duck-foot bend onto the pump
suction, the following apply:

5.8.5 Stop/start frequency

Pump sets are normally suitable for the number of
equally spaced stop/starts per hour shown in the table
below. Check capability of the driver and
control/starting system before commissioning.

Where duty and standby pumps are installed it is
recommended that they are run alternately every week.

5.9 Stopping and shutdown

a) Close the outlet valve, but ensure

that the pump runs in this condition for no more

than a few seconds.
b) Stop the pump.
c) Switch off flushing and/or cooling/heating liquid

supplies at a time appropriate to the process.
d) For prolonged shut-downs and

especially when ambient temperatures are likely to

drop below freezing point, the pump and any cooling

and flushing arrangements must be drained or

otherwise protected.

Page 24 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

5.10 Hydraulic, mechanical and electrical
duty

This product has been supplied to meet the performance
specifications of your purchase order, however it is
understood that during the life of the product these may
change. The following notes may help the user decide
how to evaluate the implications of any change. If in doubt
contact your nearest Flowserve office.

5.10.1 Specific gravity (SG)

Pump capacity and total head in metres (feet) do not
change with SG, however pressure displayed on a
pressure gauge is directly proportional to SG. Power
absorbed is also directly proportional to SG. It is therefore
important to check that any change in SG will not overload
the pump driver or over-pressurize the pump.

5.10.2 Viscosity

For a given flow rate the total head reduces with
increased viscosity and increases with reduced
viscosity. Also for a given flow rate the power absorbed
increases with increased viscosity, and reduces with
reduced viscosity. It is important that checks are made
with your nearest Flowserve office if changes in
viscosity are planned.

5.10.3 Pump speed

Changing pump speed effects flow, total head, power
absorbed, NPSHR, noise and vibration. Flow varies in
direct proportion to pump speed, head varies as speed
ratio squared and power varies as speed ratio cubed. The
new duty, however, will also be dependent on the system
curve. If increasing the speed, it is important therefore to
ensure the maximum pump working pressure is not
exceeded, the driver is not overloaded, NPSHA > NPSHR,
and that noise and vibration are within local requirements
and regulations.

5.10.4 Net positive suction head (NPSHA)

NPSH available (NPSHA) is a measure of the head
available in the pumped liquid, above its vapor
pressure, at the pump suction branch.

NPSH required (NPSHR) is a measure of the head
required in the pumped liquid, above its vapor pressure, to
prevent the pump from cavitating. It is important that
NPSHA > NPSHR. The margin between NPSHA > NPSHR
should be as large as possible.

If any change in NPSHA is proposed, ensure these
margins are not significantly eroded. Refer to the pump
performance curve to determine exact requirements
particularly if flow has changed.

If in doubt please consult your nearest Flowserve office
for advice and details of the minimum allowable margin
for your application.

5.10.5 Pumped flow

Flow must not fall outside the minimum and maximum
continuous safe flow shown on the pump performance
curve and or data sheet.

6 MAINTENANCE

6.1 General

It is the plant operator's responsibility to ensure
that all maintenance, inspection and assembly work is
carried out by authorized and qualified personnel who
have adequately familiarized themselves with the
subject matter by studying this manual in detail. (See
also section 1.6.2.)

Any work on the machine must be performed when it is
at a standstill. It is imperative that the procedure for
shutting down the machine is followed, as described in
section 5.9.

On completion of work all guards and safety devices
must be re-installed and made operative again.

Before restarting the machine, the relevant instructions
listed in section 5, Commissioning, start up, operation
and shut down, must be observed.

Oil and grease leaks may make the ground slippery.
Machine maintenance must always begin and finish
by cleaning the ground and the exterior of the
machine.

If platforms, stairs and guard rails are required for
maintenance, they must be placed for easy access to
areas where maintenance and inspection are to be
carried out. The positioning of these accessories must
not limit access or hinder the lifting of the part to be
serviced.

When air or compressed inert gas is used in the
maintenance process, the operator and anyone in the
vicinity must be careful and have the appropriate
protection.

Do not spray air or compressed inert gas on skin.
Do not direct an air or gas jet towards other people.
Never use air or compressed inert gas to clean clothes.

Page 25 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Before working on the pump, take measures to prevent
an uncontrolled start. Put a warning board on the
starting device with the words:
"Machine under repair: do not start".

With electric drive equipment, lock the main switch
open and withdraw any fuses. Put a warning board on
the fuse box or main switch with the words:
"Machine under repair: do not connect".

Never clean equipment with inflammable solvents or
carbon tetrachloride. Protect yourself against toxic
fumes when using cleaning agents.

6.2 Maintenance schedule

It is recommended that a maintenance plan and
schedule is adopted, in line with these User
Instructions, to include the following:
a) Any auxiliary systems installed must be monitored, if

necessary, to ensure they function correctly.

b) Gland packings must be adjusted correctly to give

visible leakage and concentric alignment of the
gland follower to prevent excessive temperature of
the packing or follower.

c) Check for any leaks from gaskets and seals.

The correct functioning of the shaft seal must be
checked regularly.

d) Check bearing lubricant level, and if the hours run

show a lubricant change is required.

e) Check that the duty condition is in the safe

operating range for the pump.

f) Check vibration, noise level and surface temperature at

the bearings to confirm satisfactory operation.

g) Check dirt and dust is removed from areas around

close clearances, bearing housings and motors.

h) Check coupling alignment and re-align if necessary.

Our specialist service personnel can help with
preventative maintenance records and provide
condition monitoring for temperature and vibration to
identify the onset of potential problems.

If any problems are found the following sequence of
actions should take place:
a) Refer to section 7, Faults; causes and remedies, for

fault diagnosis.

b) Ensure equipment complies with the

recommendations in this manual.

c) Contact Flowserve if the problem persists.

6.2.1 Routine inspection (daily/weekly)

The following checks should be made

and the appropriate action taken to remedy any
deviations:

a) Check operating behavior. Ensure noise, vibration

and bearing temperatures are normal.

b) Check that there are no abnormal fluid or lubricant

leaks (static and dynamic seals) and that any
sealant systems (if fitted) are full and operating
normally.

c) Check that shaft seal leaks are within acceptable

limits.

d) Check the level and condition of oil lubricant. On

grease lubricated pumps, check running hours
since last recharge of grease or complete grease
change.

e) Check any auxiliary supplies eg heating/cooling (if

fitted) are functioning correctly.

Refer to the manuals of any associated

equipment for routine checks needed.

6.2.2 Periodic inspection (six monthly)

a) Check foundation bolts for security

of attachment and corrosion.

b) Check pump running records for hourly usage to

determine if bearing lubricant requires changing.

c) The coupling should be checked for correct

alignment and worn driving elements.

Refer to the manuals of any associated

equipment for periodic checks needed.

6.2.3 Re-lubrication

Lubricant and bearing temperature analysis can be
useful in optimizing lubricant change intervals. In
general however, the following is recommended.

Oil lubricated bearings 6.2.3.1

Normal oil change interval for mineral oil lubricated
pumps is every six months.

When synthetic oils are used the lubrication interval can
increase to 18 months, and up to 36 months for the ISO
3A construction of pumps.

For pumps on hot service or in severely damp or
corrosive atmosphere, the oil will require changing more
frequently. Lubricant and bearing temperature analysis
can be useful in optimizing lubricant change intervals.

The lubricating oil should be a high quality mineral oil
having foam inhibitors or synthetic without foam
inhibitors for oil mist. Synthetic oils may also be used if
checks show that the rubber oil seals will not be
adversely affected.

Page 26 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Part

no.

Designation

Number of pumps

(including stand-by)

2 3 4 5 6/7

8/9

10(+)

2200

Impeller 1 2 3 30%

2100

Shaft 1 2

3

30%

3712.1

Bearing locknut

1 2 3 4 50%

2400

Sleeve (if fitted)

2 3 4

50%

3011

Radial ball bearing

1 2 3 4 50%

3013

Thrust bearing

1 2 3 4 50%

4590.1 *

Gasket

4 6 8 9 12

150%

4610.1

O-ring

4 6 8 9 12

150%

4610.2

O-ring

4 6 8 9 10

100%

4610.6

O-ring

4 6 8 9 10

100%

2540

Deflector 1 2

3

30%

4130

Gland packing

2 3 4

40%

4134

Lantern ring

1 2 3

30%

4200

Mechanical seals

1 2 3

30%

4305

V-ring 1 2

3

30%

-

Power end

- - - - - 1 2

4590.1

Gasket

8

12

16

18

24

300%

2912.1 /

2912.2

Impeller nut

1 2 3

30%

4610.4

O-ring
(if sleeve fitted)

2 3 4

50%

4610.5

O-ring

4 6 8 9 12

150%

6700.2

Key 1 2

3

30%

The bearing temperature may be allowed to rise to
50 ºC (90 ºF) above ambient, but should not exceed
82 ºC (180 ºF) (API 610 limit). A continuously rising
temperature, or an abrupt rise, indicate a fault.

Pumps that handle high temperature liquids may
require their bearings to be cooled to prevent bearing
temperatures exceeding their limits.

Grease lubricated bearings 6.2.3.2

When grease nipples are fitted, one charge between
grease changes is advisable for most operating
conditions; ie 2 000 hours interval. Normal intervals
between grease changes are 4 000 hours.

For food grade grease the grease change and
relubrication intervals are half those of conventional
greases.

The characteristics of the installation and severity of
service will determine the frequency of lubrication.
Lubricant and bearing temperature analysis can be useful
in optimizing lubricant change intervals.

The bearing temperature may be allowed to rise to
55 ºC (99 ºF) above ambient, but should not exceed
95 ºC (204 ºF).

To ensure continued satisfactory operation, replacement
parts to the original design specification should be obtained
from Flowserve. Any change to the original design
specification (modification or use of a non-standard part) will
invalidate the pump safety certification.

6.3.2 Storage of spares

Spares should be stored in a clean dry area away from
vibration. Inspection and re-treatment of metallic
surfaces (if necessary) with preservative is
recommended at 6 monthly intervals.

6.4 Recommended spares

For two years operation (as per VDMA 24296).

Never mix greases containing different

bases, thickeners or additives.

6.2.4 Mechanical seals

When leakage becomes unacceptable the seal [4200]
will need replacement.

6.2.5 Gland packing

The stuffing box split gland can be completely removed for
re-packing or to enable the addition of extra rings of
packing. The stuffing box is normally supplied with a
lantern ring to enable a clean or pressurized flush to the
center of the packing. If not required, this can be replaced
by an extra 2 rings of packing.

6.3 Spare parts

6.3.1 Ordering of spares

Flowserve keeps records of all pumps that have been
supplied. When ordering spares the following
information should be quoted.

1) Pump serial number.

2) Pump size.

3) Part name – taken from section 8.

4) Part number – taken from section 8.

5) Number of parts required.

(The pump size and serial number are shown on the
pump nameplate.)

* Note: for recessed impeller version replace with the following part:

Additional spares for keyed impeller option

6.5 Tools required

A typical range of tools that will be required to maintain
these pumps is listed below.

Readily available in standard tool kits, and dependent
on pump size:

 Open ended spanners (wrenches) to suit up to

M 48 screws/nuts

 Socket spanners (wrenches), up to M 48 screws
 Allen keys, up to 10 mm (A/F)
 Range of screwdrivers
 Soft mallet

Page 27 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Fastener

Screw size

Torque Nm (lbf•ft)

All except where
otherwise stated

M8
M10
M12
M16
M20

16 (12)
25 (18)
35 (26)
80 (59)

130 (96)

Impeller nut

M12
M16
M22
M24

16 (12)
41 (31)

106 (79)

135 (100)

Temp

ºC

(ºF)

Clearance mm (in.)

Impellers

up to

210 mm

Impellers

211 mm to

260 mm

Impellers

over 260 mm

(except *)

(*) 150-400
(*) 200-400
(*) 150-500

50 (122)
100 (212)
150 (302)
200 (392)
250 (482)

0.3 (0.012)

0.4 (0.016)

0.5 (0.020)

0.6 (0.024)

0.7 (0.028)

0.4 (0.016)

0.5 (0.020)

0.6 (0.024)

0.7 (0.028)

0.8 (0.032)

0.5 (0.020)

0.6 (0.024)

0.7 (0.028)

0.8 (0.032)

0.9 (0.036)

1.0 (0.040)

1.0 (0.040)

1.1 (0.044)

1.2 (0.048)

1.3 (0.052)

Indicator pattern

Rotation equivalent to

0.1 mm axial movement

More specialized equipment:

 Bearing pullers
 Bearing induction heater
 Dial test indicator
 C-spanner (wrench) - for removing shaft nut.

(If difficulties in sourcing are encountered, consult
Flowserve.)

 Coupling grip/shaft spanner

6.6 Fastener torques

For the tightening sequence also refer to good

industry practice. See section 10.3, Reference 6, for more
detail.

Non-metallic gaskets incur creep
relaxation - before commissioning the pump check and
retighten fasteners to tightening torques stated.

6.7 Setting impeller clearance

This procedure may be required after the pump has
been dismantled or a different clearance is required.

Before carrying out this procedure ensure that the
mechanical seal(s) [4200] fitted can tolerate a change in
their axial setting, otherwise it will be necessary to
dismantle the unit and reset the seal axial position after
adjusting the impeller clearance.

a) Disconnect the coupling if it has limited axial flexibility.
b) The impeller adjustment is easily made externally

by loosening the screws [6570.1/2] and rotating the
bearing carrier [3240] to obtain the proper
clearance.

6.7.1 Setting open impeller (OP) front clearance

a) Turn the bearing carrier [3240] clockwise until the

impeller [2200] comes into light contact with the
front profile on the casing [1100]. Rotating the shaft
[2100] at the same time will accurately determine
when a detectable rub is obtained. This is the zero
clearance setting.

b) Rotating the bearing carrier [3240] the width of one of

the indicator patterns cast into the bearing carrier
moves the impeller [2200] axially 0.1 mm (0.004 in.).

Example: for an impeller setting of 0.4 mm, (0.016 in.)
simply move the bearing carrier [3240]
counterclockwise four indicator patterns for the
required clearance.

c) Use the indicator pattern closest to the top center of

the bearing housing as the reference point to begin
adjustment.

d) After obtaining the proper clearance, listed in the

table above, tighten the screws [6570.1] evenly to
lock the impeller [2200] and shaft [2100] assembly.
Tightening the set screws [6570.1] will cause the
impeller to move 0.05 mm (0.002 in.) closer to the
rear cover because of the internal clearance in the
bearing carrier threads. This must be considered
when setting the impeller clearance.

e) Check that the shaft [2100] can turn freely without

binding.

f) If a cartridge seal [4200] is fitted it should be reset

at this point.

g) Ensure the coupling distance between shaft ends

(DBSE) is correct. Reset/re-align if necessary.

6.7.2 Setting reverse vane (RV) impeller rear
clearance

a) Reverse vane impellers are set off the cover. This

allows the impeller to be set without the casing.

Page 28 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

b) Turn the bearing carrier [3240] counter-clockwise

until the impeller [2200] comes into light contact
with the rear cover [1220]. Rotating the shaft
[2100] at the same time will accurately determine
when a detectable rub is obtained. This is the zero
clearance setting.

c) Rotating the bearing carrier [3240] the width of one of

the indicator patterns cast into the bearing carrier
moves the impeller [2200] axially 0.1 mm (0.004 in.).
Example: for an impeller setting of 0.4 mm (0.016 in.)
simply move the bearing carrier clockwise four indicator
patterns for the required clearance.

d) Use the indicator pattern closest to the top center of

the bearing housing as the reference point to begin
adjustment.

e) After obtaining the proper clearance, listed in the table

above, tighten the set-screws [6570.1] evenly to lock
the impeller [2200] and shaft [2100] assembly.
Tightening the screws [6570.1] will cause the impeller
to move 0.05 mm (0.002 in.) closer to the rear cover
because of the internal clearance in the bearing
carrier threads. This must be considered when setting
the impeller clearance.

f) If a cartridge seal [4200] is fitted it should be reset

at this point.
g) Check that the shaft can turn freely without binding.
h) Ensure the coupling distance between shaft ends

(DBSE) is correct. Reset/re-align if necessary.

6.7.3 Setting recessed impeller rear clearance

a) Recessed open impellers are set off the cover. This

allows the impeller to be set without the casing.

b) Turn the bearing carrier [3240] counter-clockwise

until the impeller [2200] comes into light contact
with the cover [1220]. Rotating the shaft [2100] at
the same time will accurately determine when a
detectable rub is obtained. This is the zero
clearance setting.

c) Rotating the bearing carrier [3240] the width of one of

the indicator patterns cast into the bearing carrier
moves the impeller [2200] axially 0.1 mm (0.004 in.).
Example: for an impeller setting of 1.5 mm (0.059 in.)
simply move the bearing carrier clockwise fifteen
indicator patterns for the required clearance.

d) Use the indicator pattern closest to the top center of

the bearing housing as the reference point to begin
adjustment.

e) After obtaining the proper clearance of 1.5 mm

(0.059 in.) to 2 mm (0.079 in.), tighten the set­screws [6570.1/2] evenly to lock the impeller [2200]
and shaft [2100] assembly. Tightening the screws

will cause the impeller to move 0.05 mm (0.002 in.)
closer to the rear cover because of the internal
looseness in the bearing carrier threads. This must
be considered when setting the impeller clearance.

If possible, check results with a feeler gauge.

f) If a cartridge seal [4200] is fitted it should be reset

at this point.
g) Check that the shaft can turn freely without binding.
h) Ensure the coupling distance between shaft ends

(DBSE) is correct. Reset/re-align if necessary.

6.8 Disassembly

Refer to Safety section before dismantling the

pump.

Before dismantling the pump for

overhaul, ensure genuine Flowserve replacement parts
are available.

Refer to sectional drawings for part numbers and
identification. (See section 8, Parts lists and drawings.)

6.8.1 Bearing housing disassembly

To remove, proceed as follows:
a) Disconnect all auxiliary pipes and tubes where

applicable.
b) Remove coupling guard and disconnect coupling.
c) If oil lubricated frame, drain oil by removing drain plug.
d) Record the gap between the bearing carrier [3240]

and bearing housing [3200] so that this setting can

be used during workshop assembly.
e) Place hoist sling through bearing housing adaptor

window.
f) Remove casing nuts [6582.1] and support foot

[3134] to baseplate screws.

Page 29 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

g) Remove bearing housing assembly from pump

casing [1100].

h) The two threaded holes in the adaptor flange can

be used for jacking screws to assist with removal.

i) Remove pump casing gasket [4590.1] and discard. A

replacement gasket will be required for assembly.

j) Clean gasket mating surfaces.

6.8.2 Impeller removal

NEVER APPLY HEAT TO REMOVE THE

IMPELLER. TRAPPED OIL OR LUBRICANT MAY
CAUSE AN EXPLOSION.

Impeller removal with threaded on 6.8.2.1

impeller/locking screw

a) Ensure the pump bearing housing assembly is

firmly fixed to the work bench.

b) Fit a chain wrench or bolt a bar to the holes in the

coupling half, or fit a keyed shaft wrench directly to
the shaft. Make sure the wrench or bar cannot slip.

c) Unscrew the locking screw [6570.6] in the impeller

hub completely (applicable only on the locking
screw configuration).

d) Turn the shaft [2100] counter-clockwise as viewed

from the drive end of the shaft with the wrench.

e) Give the shaft a quick turn clockwise to sharply

strike the wrench handle against the work bench
surface or a wooden block. A few sharp strikes by
the handle onto the bench/wooden block will free
the impeller from the shaft.

f) Alternatively, twist the impeller by firmly grabbing

hold of the impeller and twist it counter-clockwise.
To make the wrench handle impact on the work
bench. This method requires the use of metal
mesh reinforced gloves.

g) Remove and discard the impeller O-ring [4610.1].

Use a new O-ring for assembly.

Impeller removal with key drive impeller 6.8.2.2

c) Remove impeller nut [2912.1/2912.2] complete with

O-ring [4610.5], which should be discarded. (A new

O-ring will be required for assembly.)
d) Pull impeller [2200] off shaft [2100].
e) Remove impeller key [6700.2].
f) Remove impeller sealing gasket [4590.4] and discard.

(A new sealing gasket will be required for assembly.)

6.8.3 Cover and seal

The seal manufacturer's instructions should be followed
for dismantling and assembly, but the following guidance
should assist with most seal types:
a) Remove shaft guard (if fitted).
b) Remove the seal gland nuts, if a separate seal

gland is fitted, and slide the seal gland away.

Remove the two cover nuts [6580].

c) Loosen the grub screws (used in most mechanical

seals).

d) Carefully pull off the cover and mechanical seal

rotating element(s).

e) Remove the seal cover.
f) Remove shaft sleeve (if fitted).
g) On non-cartridge seals the stationary seat remains

in the cover/mechanical seal gland with its sealing
member. Remove only if damaged or worn out.

h) On pumps fitted with gland packing, the packing

and lantern ring should be removed only if the
packing is to be replaced.

6.8.4 Bearing housing

a) Take grub screw(s) out of the pump half coupling and

pull off this coupling and remove the coupling key.
b) Remove support foot [3134] (if necessary).
c) Remove the pump side liquid deflector [2540] and/or

labyrinth seal rotary half (depending on option fitted).
d) Slacken the bearing carrier screws to initiate bearing

carrier release.
e) Remove bearing carrier [3240] and shaft [2100]

assembly from the bearing housing [3200] by pulling it

towards the coupling end.
f) Remove bearing circlip [6544] (or bearing lock nut

[3712.2] if paired angular contact bearings are fitted).

Bearing carrier locking rings are left-hand

thread.
g) Remove drive side v-ring [4305] and/or labyrinth

seal rotary half (depending on option fitted).
h) Remove bearing carrier [3240].
i) Remove pump side bearing [3011].
j) Release the self-locking drive side bearing nut

[3712.1] and remove drive side bearing [3013].
k) When pressing bearings off the shaft, use force on

the inner race only.

6.9 Examination of parts

Used parts must be inspected before

assembly to ensure the pump will subsequently run
properly. In particular, fault diagnosis is essential to

enhance pump and plant reliability.

6.9.1 Casing, cover and impeller

Inspect for excessive wear, pitting, corrosion, erosion or
damage and any sealing surface irregularities. Replace
as necessary.

6.9.2 Shaft and sleeve (if fitted)

Replace if grooved or pitted. With the bearing mounting
diameters (or bearing outer) supported by V-blocks, check
that the shaft runouts are within 0.025 mm (0.001 in.) at
the coupling end and 0.050 mm (0.002 in.) at the
sleeve/impeller end.

Page 30 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Grease

retainer

[3864]

6.9.3 Gaskets, O-rings and V-ring when fitted

After dismantling, discard and replace.

6.9.4 Bearings

It is recommended that bearings are not re-used after
any removal from the shaft.

6.9.5 Bearing labyrinths/isolators

Labyrinth seals and bearing isolators should be
inspected for damage but are normally non-wearing
parts and can be re-used.

The lubricant, bearings and bearing housing seals are to
be inspected for contamination and damage. If oil bath
lubrication is utilized, these provide useful information on
operating conditions within the bearing housing. If bearing
damage is not due to normal wear and the lubricant
contains adverse contaminants, the cause should be
corrected before the pump is returned to service.

Bearing seals are not totally leak free devices. Oil from
these may cause staining adjacent to the bearings.

6.9.6 Bearing housing and carrier

Inspect the bearing carrier circlip groove. Ensure it is
free from damage and that housing lubrication
passages are clear. Replace grease nipples or the filter

breather (where fitted) if damaged or clogged. On oil
lubricated versions, the oil level sight glass should be
replaced if oil stained.

6.10 Assembly

To assemble the pump consult the sectional drawings.
See section 8, Parts lists and drawings.

Ensure threads, gasket and O-ring mating faces are
clean. Apply thread sealant to non-face-sealing pipe
thread fittings.

6.10.1 Bearing housing and rotating element
assembly

a) Clean the inside of the bearing housing [3200],

bearing carrier [3240] and bores for bearings.

b) Attach bearing housing support foot [3134].
c) Fit the thrust ball bearing [3013] on to shaft [2100].

Grease retainer (clearance type) is only

fitted on grease lubricated units

The following methods are recommended for fitting

the bearings onto the shaft:

Method 1: Use a hotplate, hot bath, oven or

induction heater to heat the bearing race so it can

easily be placed in position then allowed to shrink

and grip the shaft. It is important that the

temperature is not raised above 100 ºC (212 ºF).

Method 2: Press the bearing onto the shaft using

equipment that can provide a steady, even load to

the inner race. Take care to avoid damaging the

bearing and shaft.

d) With bearings at ambient temperature, screw on the

self-locking bearing locknut [3712.1] (with its

polyamide insert facing away from the bearing) until

tight.
e) With the double row thrust bearing place the

bearing circlip [6544] over the shaft, with the

tapered face facing the impeller end.
f) With the heavy duty thrust bearing option, the lock nut

[3712.2], [3864] grease retainer and [3712.2] if grease

lubricated, should be placed on the shaft with the

larger diameter end facing the impeller end.
g) Fit pump radial ball bearing [3011] onto the shaft

using Method 1 or 2 above.
h) With the NUP roller bearing option, the loose ring

should be against the shaft shoulder.
i) Fit O-ring [4610.2] on the bearing carrier. Lightly

lubricate the bearing carrier bore and O-ring.
j) Ensure the shaft keyway edges are free of burrs.

During installation, use shimming or tape over the

keyway to avoid damaging the drive side bearing

seals.

k) On grease lubricated pumps, ¾ fill the space between

bearing races with the appropriate grease.
l) Slide the bearing carrier [3240] onto the shaft/bearing

The double row thrust bearing must not

have a filling slot, as such bearings are limited to
taking thrust in only one direction. If the pair of
angular contact thrust bearings are to be fitted,
these must be mounted back-to-back, as shown
below:

assembly and insert inner circlip [6544] into the carrier

groove or screw up the bearing locking ring.
m) Check shaft [2100] for free rotation.
n) Fit the labyrinth ring [4330] into the bearing housing

[3200] ensuring the drain hole faces the bearing

and is at the 6 o'clock position.

Page 31 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Bearing housing

Dia. X mm (in.)

Z mm (in.)

Frame 1

24 (0.945)

9 (0.354)

Frame 2

32 (1.260)

17 (0.669)

Frame 3

42 (1.654)

9 (0.354)

Frame 4

48 (1.890)

22 (0.866)

0.5 to 2 mm
(0. 02 to 0.08 in.)

o) Install the shaft assembly into the bearing housing

[3200] until the gap is approximately 5 mm (0.2 in.).

Fit the bearing carrier screws [6570.1] but do not
tighten.

p) Press drive side v-ring [4305] and pump side liquid

deflector [2540] onto shaft [2100] where applicable.
The V-ring type shall be fitted with light contact with
the bearing carrier [3240].

q) The pump side deflector [2540] (this feature is

integral with some proprietary labyrinth seals)
should only be set in its final position after setting
the shaft axial position.

r) Temporarily fit the cover [1220] to the power-end.

The cover, above 125 size, is retained by studs
[6580] and their nuts. The shaft [2100] may now be
positioned in relation to the cover face, by rotating
the carrier, position as shown below:

t) The pump side deflector [2540] may then be moved

towards the bearing housing [3200] and set with its
clearance.

6.10.2 Seal cover and seal assembly

a) Extreme cleanliness is required. The sealing faces

and shaft [2100] or sleeve [2400] surface must be

free from scratches or other damage.
b) Refer to section 6.11, Seal arrangements, for seal

diagrams.
c) Carefully press the stationary seat into the cover

[1220] or mechanical seal cover [4213], ensuring

that the seating ring is not deformed. Where an

anti-rotation pin is fitted ensure that correct

engagement with the slot is achieved.

d) Place any separate seal covers over the shaft [2100].
e) Refer to manufacturer's instructions to position the

mechanical seal rotating elements. Tighten any

drive screws in the seal drive collar. For precise

compression most cartridge seals should be set

after complete pump assembly.
f) Fit the cover [1220] into the bearing housing [3200]

and tighten all fasteners.

6.10.3 Gland packed stuffing box assembly

a) Assemble the gland packing [4130] into the cover

before fitting on to the shaft [2100], see 6.11.6.
b) Stagger the joints in the gland packing by 90

degrees to each other.
c) The lantern ring halves [4134], if required, should be

positioned mid-way along the packing.
d) Position the gland [4120] squarely against the last

ring and tighten the gland nuts finger-tight only.

Install into bearing housing assembly, fit the two

studs and nuts to hold the cover [1220] in place.
e) Check that the shaft [2100] rotates freely.

6.10.4 Impeller assembly and setting

Impeller assembly and setting - screwed 6.10.4.1

on impeller/locking screw

a) Fit a new O-ring [4610.1] into the impeller [2200]

using a small amount of grease to hold it in place.

Apply anti-galling compound (which does not

contain copper) to the impeller thread to help

subsequent removal.
b) Assemble impeller [2200] onto the shaft [2100].
c) Tighten the impeller. Use the same method as in

disassembly but rotating in opposite direction. A

few sharp strikes will tighten it to the correct level.
d) Fit a new O-ring [4610.6] into the locking screw

[6570.6] using a small amount of grease to hold it in

place. Apply anti-galling compound (which does

not contain copper) to the impeller thread to help

subsequent removal (applicable only on the locking

screw configuration).
e) Tighten the locking screw (left hand thread) to the

predefined torque. Refer to section 6.6 (applicable

only on the locking screw configuration)

Page 32 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Bearing housing

Setting dimension mm (in.)

X

Y

Frame 1

23.5 (0.925)

11.0 (0.433)

Frame 2

34.0 (1.339)

19.0 (0.748)

Frame 3

33.5 (1.319)

11.0 (0.433)

Frame 4

51.5 (2.028)

24.0 (0.945)

Bearing housing

Setting dimension mm (in.)

X

Y

Frame 1

23.5 (0.925)

11.0 (0.433)

Frame 2

34.0 (1.339)

19.0 (0.748)

Frame 3

33.5 (1.319)

11.0 (0.433)

Frame 4

51.5 (2.028)

24.0 (0.945)

Impeller assembly with key drive impeller 6.10.4.2

a) Fit a new impeller sealing gasket [4590.4] against

shaft shoulder.

b) Fit impeller key [6700.2].
c) Assemble impeller [2200] onto the shaft [2100].
d) Fit a new O-ring [4610.5] into the impeller nut

[2912.1/2912.2] groove.

e) Apply anti-galling compound (which does not

contain copper) to the impeller nut threads to help
any subsequent removal.

f) Fit impeller nut [2912.1/2] onto the shaft [2100] and

torque up.

6.10.5 Assembly of power-end into casing

a) Fit a new gasket [4590] into the casing [1100].

On the recessed impeller a new gasket is

required each side of the distance ring [2510.2].

b) Ensure bearing housing and adaptor concentricity

and squareness.

c) Install the power-end assembly into the pump

casing. Coat the studs [6572.1] with anti-galling
compound and tighten nuts [6580.1] onto casing.

d) Check impeller clearance against original setting or

process requirement and adjust as necessary. (See
section 6.7, Setting impeller clearance.)

e) Ensure that all other items have been re-attached

and all fasteners tightened to the correct torques,
then follow the instructions in the sections on
Installation and Commissioning.

6.11 Sealing arrangements

The following section shows details of the seal
arrangements. The dimensions provided are for non-step
balanced mechanical seals conforming to EN 12757 L1K
and L1N. Contact your nearest Flowserve sales office or
service center if you require further information, such as a
mechanical seal dimensional drawing, or are unsure of the
specific arrangement supplied. Refer also to section

4.6.5, Auxiliary piping.

6.11.1 Single seal types

Single stepped balanced seal 6.11.1.1

Single unbalanced (or inherently balanced) 6.11.1.2

seal

Single seal with external neck bush 6.11.1.3

Page 33 of 52 flowserve.com

Q - Rp ¼ in. quench

D - Rp ¼ in. drain

F - Rp ¼ in. flush

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Bearing housing

Setting dimension mm (in.)

X

Y

Frame 1

23.5 (0.925)

11.0 (0.433)

Frame 2

34.0 (1.339)

19.0 (0.748)

Frame 3

33.5 (1.319)

11.0 (0.433)

Frame 4

51.5 (2.028)

24.0 (0.945)

Pump

size

Setting dimension Z mm (in.)

Frame 1

Frame 2

Frame 3

Frame 4

125

41.5 (1.634)

- - -

160

41.5 (1.634)

49.0 (1.929)

- - 200

36.5 (1.437)

49.0 (1.929)

- - 250

-

44.0 (1.732)

45.0 (1.771)

-

315

-

44.0 (1.732)

45.0 (1.771)

65.0 (2.559)

400 - -

36.5 (1.437)

57.0 (2.244)

500

-

44.0 (1.732)

45.0 (1.771)

65.0 (2.559)

EN12 757 L1N
EN12 757 L1K

Pump

size

Setting dimension mm (in.)

Frame 1

Frame 2

Frame 3

Frame 4

X Y X Y X Y X

Y

125

12.5

(0.492) 0 (0)

- - - - - - 160

12.5

(0.492) 0 (0)

5.5

(0.217)

-9.5

(-0.374)

- - -

-

200

17.5

(0.689)

5.0

(0.197)

5.5

(0.217)

-9.5

(-0.374)

- - - - 250 - -

10.6

(0.417)

-4.4

(-0.173)

18.3

(0.720)

-4.3

(-0.169)

- - 315 - -

10.6

(0.417)

-4.4

(-0.173)

18.3

(0.720)

-4.3

(-0.169)

-4.7

(-0.185)

-32.3

(-1.272)

400 - - - -

27.0

(1.063)

-4.3

(-0.169)

3.5

(0.138)

-24.0

(-0.945)

500 - -

10.6

(0.417)

-4.4

(-0.173)

18.3

(0.720)

-4.3

(-0.169)

-4.7

(-0.185)

-32.3

(-1.272)

Pump

size

Setting dimension mm (in.)

Frame 1

Frame 2

Frame 3

Frame 4

X Y X Y X Y X

Y

125

20.0

(0.787)

31.5

(1.240)

- - - - -

-

160

20.0

(0.787)

31.5

(1.240)

28.0

(1.102)

41.5

(1.634)

- - -

-

200

20.0

(0.787)

26.5

(1.043)

28.0

(1.102)

41.5

(1.634)

- - -

-

250

-

-

28.0

(1.102)

36.4

(1.433)

27.5

(1.083)

33.7

(1.327)

-

-

315

-

-

28.0

(1.102)

36.4

(1.433)

27.5

(1.083)

33.7

(1.327)

45.5

(1.791)

56.7

(2.232)

400

- - -

-

27.5

(1.083)

25.3

(1.996)

45.5

(1.791)

48.3

(1.902)

500

-

-

28.0

(1.102)

36.4

(1.433)

27.5

(1.083)

33.7

(1.327)

45.5

(1.791)

56.7

(2.232)

Q - Rp ¼ in. quench

D - Rp ¼ in. drain
F - Rp ¼ in. flush
Z - Position of lip seal hard sleeve

Q - Rp ¼ in. quench
D - Rp ¼ in. drain
F - Rp ¼ in. flush

BI - Rp ¼ in. barrier liquid inlet
BO - Rp ¼ in. barrier liquid outlet
F - Rp ¼ in. flush

Single seal with external lip seal 6.11.1.4

NB: Lever flange away after fitting hard sleeve to shaft.

Single internal seal with internal and 6.11.1.5

external neck bush

6.11.2 Cartridge seal types

Cartridge seal in Seal Sentry conical cover 6.11.2.1

Hooked sleeve' cartridge seal 6.11.2.2

For S see seal supplier's instructions

6.11.3 Tandem seal types

Tandem seal with Flowserve eccentric 6.11.3.1

pumping annulus circulation

Page 34 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Pump

size

Setting dimension X mm (in.)

Frame 1

Frame 2

Frame 3

Frame 4

125

11.0 (0.433)

- - -

160

11.0 (0.433)

17.5 (0.689)

- - 200

6.0 (0.236)

17.5 (0.689)

- - 250

-

12.4 (0.488)

14.4 (0.567)

-

315

-

12.4 (0.488)

14.3 (0.563)

32.3 (1.272)

400 - -

5.7 (0.224)

24.0 (0.945)

500

-

12.4 (0.488)

14.3 (0.563)

32.3 (1.272)

4120

4130

4134

BI - Rp ¼ in. barrier liquid inlet
BO - Rp ¼ in. barrier liquid outlet

6.11.4 Double seal types

Double back-to-back seal with Flowserve 6.11.4.1

eccentric pumping annulus circulation

6.11.5 External seal types

External seal 6.11.5.1

D - drain

6.11.6 Packed gland seal types

Packed gland with fiber packing 6.11.6.1

Page 35 of 52 flowserve.com

F - Rp ¼ in. flush

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

FAULT SYMPTOM

P u m p ov e rh ea ts an d s ei ze s



Be a ri ng s h ave s ho r t l if e



P u m p vi b ra te s o r is no i sy



M e c ha ni ca l s ea l h a s sh o rt li f e



M e c ha ni ca l s ea l l e ak s ex ce s si v el y



P u m p re q ui re s e xc e ssi v e po w er



P u m p lo s es p ri m e a fte r s ta rt i ng



I n s uf fi ci e nt p re ss u re de v el o pe d



I n s uf fi ci e nt c ap ac it y de li ve r ed



P u m p do e s no t d el iv er l iq ui d



POSSIBLE CAUSES

POSSIBLE REMEDIES

A. System troubles





Pump not primed or filled with liquid.

Check complete filling.

 





Pump or suction pipe not completely filled with
liquid. (Where not a self-priming arrangement.)

Vent and/or prime.

  



Suction lift too high or level too low.

Check NPSHA > NPSHR, proper submergence,
losses at strainers and fittings.

 





Insufficient margin between suction pressure and
vapor pressure.

  

Excessive amount of air or gas in liquid.

Check and purge pipes and system.

 



Air or vapor pocket in suction line.

Check suction line design for vapor pockets.

 

Air leaks into suction line.

Check suction pipe is airtight.

 

Air leaks into pump through mechanical seal,
sleeve joints, casing joint or pipe lugs.

Check and replace faulty parts.
CONSULT FLOWSERVE.

 

Foot valve too small.

Investigate replacing the foot valve.

 

Foot valve partially clogged.

Clean foot valve.

  



Inlet of suction pipe insufficiently submerged.

Check out system design.

 



Speed too low.

CONSULT FLOWSERVE.



Speed too high.

CONSULT FLOWSERVE.

  

Total head of system higher than differential head
of pump.

Check system losses.
Remedy or CONSULT FLOWSERVE.



Total head of system lower than pump design head.



Specific gravity of liquid different from design.

Check and CONSULT FLOWSERVE.







Viscosity of liquid differs from that for which
designed.

 

Operation at very low capacity.

Measure value and check minimum permitted.
Remedy or CONSULT FLOWSERVE.







Operation at high capacity.

Measure value and check maximum permitted.
Remedy or CONSULT FLOWSERVE.

B. Mechanical troubles

    



Misalignment due to pipe strain.

Check the flange connections and eliminate strains
using elastic couplings or a method permitted.



Improperly designed foundation.

Check setting of baseplate: tighten, adjust, grout
base as required.

    

Shaft bent.

Check shaft runouts are within acceptable values.
CONSULT FLOWSERVE.

7 FAULTS; CAUSES AND REMEDIES

Page 36 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

FAULT SYMPTOM

P u m p ov e rh ea ts an d s ei ze s



Be a ri ng s h ave s ho r t l if e



P u m p vi b ra te s o r is no i sy



M e c ha ni ca l s ea l h a s sh o rt li f e



M e c ha ni ca l s ea l l e ak s ex ce s si v el y



P u m p re q ui re s e xc e ssi v e po w er



P u m p lo s es p ri m e a fte r s ta rt i ng



I n s uf fi ci e nt p re ss u re de v el o pe d



I n s uf fi ci e nt c ap ac it y de li ve r ed



P u m p do e s no t d el iv er l iq ui d



POSSIBLE CAUSES

POSSIBLE REMEDIES

   

Rotating part rubbing on stationary part internally.

Check and CONSULT FLOWSERVE, if necessary.

    

Bearings worn

Replace bearings.

  

Wearing ring surfaces worn.

Replace worn wear ring/surfaces.







Impeller damaged or eroded.

Replace or CONSULT FLOWSERVE for improved
material selection.



Leakage under sleeve due to joint failure.

Replace joint and check for damage.

 

Shaft sleeve worn or scored or running off center.

Check and renew defective parts.

  

Mechanical seal improperly installed.

Check alignment of faces or damaged parts and
assembly method used.

  

Incorrect type of mechanical seal for operating
conditions.

CONSULT FLOWSERVE.

    

Shaft running off center because of worn bearings
or misalignment.

Check misalignment and correct if necessary. If
alignment satisfactory check bearings for excessive
wear.

    

Impeller out of balance resulting in vibration.

Check and CONSULT FLOWSERVE.

  

Abrasive solids in liquid pumped.





Internal misalignment of parts preventing seal ring
and seat from mating properly.





Mechanical seal was run dry.

Check mechanical seal condition and source of dry
running and repair.





Internal misalignment due to improper repairs
causing impeller to rub.

Check method of assembly, possible damage or
state of cleanliness during assembly.
Remedy or CONSULT FLOWSERVE, if necessary.

  

Excessive thrust caused by a mechanical failure
inside the pump.

Check wear condition of impeller, its clearances and
liquid passages.

 

Excessive grease in ball bearings.

Check method of regreasing.





Lack of lubrication for bearings.

Check hours run since last change of lubricant, the
schedule and its basis.





Improper installation of bearings (damage during
assembly, incorrect assembly, wrong type of
bearing etc).

Check method of assembly, possible damage or
state of cleanliness during assembly and type of
bearing used. Remedy or CONSULT
FLOWSERVE, if necessary.





Damaged bearings due to contamination.

Check contamination source and replace damaged
bearings.

C. Motor electrical problems

   

Wrong direction of rotation.

Reverse 2 phases at motor terminal box.

 

Motor running on 2 phases only.

Check supply and fuses.

  

Motor running too slow.

Check motor terminal box connections and voltage.

Page 37 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description

1100

Casing

1220

Cover

1340

Adaptor

2100

Shaft

2200

Impeller

2540

Deflector (liquid)

3011

Radial ball bearing

3013

Thrust ball bearing

3134

Support foot

3200

Bearing housing

3240

Bearing carrier

3712.1

Bearing locknut

3712.2

Bearing locknut

3853.1

Grease nipples (grease lubrication only) *

3853.2

Grease nipples (grease lubrication only) *

3855

Constant level oiler *

3856

Oil sight gauge

4200

Mechanical seal

4305

Shaft seal ring

4330

Labyrinth ring

4590.1

Gasket

4590.2

Gasket *

4610.1

O-ring

4610.2

O-ring

6544

Circlip

6569.1

Plug (filler)

6569.2

Plug *

6569.3

Plug (magnetic)

6570.1

Screw

6570.2

Screw

6570.3

Screw

6570.4

Screw

6572.1

Stud

6572.2

Stud

6580.1

Nut

6580.2

Nut

6700.1

Key

9035

Guard

8 PARTS LISTS AND DRAWINGS

8.1 Mark 3 ISO

8.1.1 Open impeller (OP) sectional drawing

8.1.2 Open impeller (OP) parts list

* Standard option

Drawing taken from B731/2082

Page 38 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description

1100

Casing

1220

Cover

1340

Adaptor

2100

Shaft

2200

Impeller

2540

Deflector (liquid)

3011

Radial ball bearing

3013

Thrust ball bearing

3134

Support foot

3200

Bearing housing

3240

Bearing carrier

3712.1

Bearing locknut

3712.2

Bearing locknut

3853.1

Grease nipples (grease lubrication only) *

3853.2

Grease nipples (grease lubrication only) *

3855

Constant level oiler *

3856

Oil sight gauge

4200

Mechanical seal

4305

Shaft seal ring

4330

Labyrinth ring

4590.1

Gasket

4590.2

Gasket *

4610.1

O-ring

4610.2

O-ring

6544

Circlip

6569.1

Plug (filler)

6569.2

Plug *

6569.3

Plug (magnetic)

6570.1

Screw

6570.2

Screw

6570.3

Screw

6570.4

Screw

6572.1

Stud

6572.2

Stud

6580.1

Nut

6580.2

Nut

6700.1

Key

9035

Guard

8.1.3 Reverse vane (RV) impeller sectional drawing

8.1.4 Reverse vane (RV) impeller parts list

* Standard option

Drawing taken from B731/2081

Page 39 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description

1100

Casing

1220

Cover

1340

Adaptor

2100

Shaft

2200

Impeller

2540

Deflector (liquid)

3011

Radial ball bearing

3013

Thrust ball bearing

3134

Support foot

3200

Bearing housing

3240

Bearing carrier

3712.1

Bearing locknut

3712.2

Bearing locknut

3855

Constant level oiler

3856

Oil sight gauge

4200

Mechanical seal

4305

Shaft seal ring

4330

Labyrinth ring

4590

Gasket

4610.1

O-ring

4610.2

O-ring

6544

Circlip

6569.1

Plug (filler)

6569.2

Plug (magnetic)

6570.1

Screw

6570.2

Screw

6570.3

Screw

6570.4

Screw

6572.1

Stud

6572.2

Stud

6580.1

Nut

6580.2

Nut

6700.1

Key

9035

Guard

2400

Sleeve *

8.2 Centerline mounted, recessed impeller and self-primer configurations

8.2.1 Centerline mounted sectional drawing

8.2.2 Centerline mounted casing parts list

Items not illustrated

* Standard option

Drawing taken from C128/002

Page 40 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description

1100

Casing

1220

Cover

1340

Adaptor

2100

Shaft

2200

Impeller

2400

Sleeve

2510

Distance ring

2540

Deflector (liquid)

3011

Radial ball bearing

3013

Thrust ball bearing

3134

Support foot

3200

Bearing housing

3240

Bearing carrier

3712.1

Bearing locknut

3712.2

Bearing locknut

3853.1

Grease nipples (grease lubrication only) *

3853.2

Grease nipples (grease lubrication only) *

3855

Constant level oiler (oil lubrication only) *

3856

Oil sight gauge

4200

Mechanical seal

4305

Shaft seal ring

4330

Labyrinth ring

4590.1

Gasket

4590.2

Gasket *

4610.1

O-ring

4610.2

O-ring

6544

Circlip

6569.1

Plug (filler)

6569.2

Plug *

6569.3

Plug (magnetic)

6570.1

Screw

6570.2

Screw

6570.3

Screw

6570.4

Screw

6572.1

Stud

6572.2

Stud

6580.1

Nut

6580.2

Nut

6700.1

Key

9035

Guard

8.2.3 Recessed impeller pump sectional drawing

8.2.4 Recessed impeller pump parts list

* Standard option

Drawing taken from B731/2083

Page 41 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description

1100

Casing

1220

Cover

1340

Adaptor

2100

Shaft

2200

Impeller

2400

Sleeve *

2540

Deflector (liquid)

3011

Radial ball bearing

3013

Thrust ball bearing

3134

Support foot

3200

Bearing housing

3240

Bearing carrier

3712.1

Bearing locknut

3712.2

Bearing locknut

3853.1

Grease nipples (grease lubrication only) *

3853.2

Grease nipples (grease lubrication only) *

3855

Constant level oiler *

3856

Oil sight gauge

4200

Mechanical seal

4305

Shaft seal ring

4330

Labyrinth ring

4590.1

Gasket

4590.2

Gasket *

4610.1

O-ring

4610.2

O-ring

6544

Circlip

6569.1

Plug (filler)

6569.2

Plug *

6569.3

Plug (magnetic)

6569.4

Plug (filler)

6570.1

Screw

6570.2

Screw

6570.3

Screw

6570.4

Screw

6572.1

Stud

6572.2

Stud

6580.1

Nut

6580.2

Nut

6700.1

Key

9035

Guard

8.2.5 Self-priming casing pump sectional drawing

8.2.6 Self-priming casing pump parts list

* Standard option

Drawing taken from C665/076

Page 42 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description

2100

Shaft

2200

Impeller

2400

Sleeve (if fitted)

2912.1

Impeller nut

2912.2

Impeller nut

4590.4

Gasket

4610.4

O-ring (if sleeve fitted)

4610.5

O-ring

6570.6

Screw

6700.2

Key

2100 2400 6700.2 2200 4610.5

2912.1

4590.4

6570.6

2912.2

4610.4

(includes
heli-coil 6589)

SOLID SHAFT
SHOWN BELOW
CENTRE-LINE.

SLEEVED SHAFT
SHOWN ABOVE
CENTRE-LINE.

8.3 Additional details

8.3.1 Bearing housing sealing details

Frame 1 and 2

8.3.2 Open impeller (OP) key drive impeller
option

Frame 3 and 4

Frame 1 to 4 proprietary labyrinth/face seals (where fitted)

Key drive design for 304/316 stainless steel and

above, secure screw with PTFE sealant (Loctite 577)

Page 43 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Item

Description (sleeved and solid shaft)

2100

Shaft

2200

Impeller

2400

Sleeve (if fitted)

4610.6

O-ring

6570.6

Screw (LH thread for impeller locking)

8.3.3 Reverse impeller (RV) - screwed locking
bolt drive impeller option

Drawing taken from B731/2221

Page 44 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

8.4 Parts interchangeability

8.4.1 Durco Mark3 ISO A hydraulic parts interchangeability

Drawing taken from E576/159, issue date 16/04/14

Page 45 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

8.4.2 Durco Mark3 ISO B hydraulic parts interchangeability

Drawing taken from E576/159, issue date 16/04/14

Page 46 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

8.4.3 Durco Mark 3 ISO self-priming pump parts interchangeability

Drawing taken from E576/159, issue date 16/04/14

Page 47 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

8.4.4 Durco Mark 3 ISO recessed impeller pump parts interchangeability

Drawing taken from E576/159, issue date 16/04/14

Page 48 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

8.5 General arrangement drawing

The typical general arrangement drawing and any
specific drawings required by the contract will be sent

to the Purchaser separately unless the contract
specifically calls for these to be included into the User
Instructions. If required, copies of other drawings
sent separately to the Purchaser should be obtained
from the Purchaser and retained with these User
Instructions.

9 CERTIFICATION

Certificates determined from the Contract requirements
are provided with these Instructions where applicable.
Examples are certificates for CE marking, ATEX
marking etc. If required, copies of other certificates sent
separately to the Purchaser should be obtained from
the Purchaser for retention with these User Instructions.

10 OTHER RELEVANT
DOCUMENTATION AND MANUALS

10.1 Supplementary User Instruction
manuals

Supplementary instruction determined from the contract
requirements for inclusion into User Instructions such as
for a driver, instrumentation, controller, sub-driver, seals,
sealant system, mounting component etc are included

under this section. If further copies of these are
required they should be obtained from the purchaser for
retention with these User Instructions.

Where any pre-printed set of User Instructions are
used, and satisfactory quality can be maintained only
by avoiding copying these, they are included at the
end of these User Instructions such as within a
standard clear protection envelope.

10.2 Change notes

If any changes, agreed with Flowserve Solution
Group, are made to the product after its supply, a
record of the details should be maintained with these
User Instructions.

10.3 Additional sources of information

Reference 1:

NPSH for Rotordynamic Pumps: a reference guide,
Europump Guide No. 1, Europump & World Pumps,
Elsevier Science, United Kingdom, 1999.

Reference 2:

Pumping Manual, 9th edition, T.C. Dickenson,
Elsevier Advanced Technology, United Kingdom, 1995.

Reference 3:

Pump Handbook, 2nd edition, Igor J. Karassik et al,
McGraw-Hill Inc., New York, 1993.

Reference 4:

ANSI/HI 1.1-1.5. Centrifugal Pumps - Nomenclature,
Definitions, Application and Operation.

Reference 5:

ANSI B31.3 - Process Piping.

Reference 6:

ESA – Guidelines for safe seal usage (flanges and
gaskets).

Page 49 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Notes:

Page 50 of 52 flowserve.com

Notes:

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Page 51 of 52 flowserve.com

DURCO MARK 3 ISO FRAME MOUNTED ENGLISH 85392719 12-14

Your Flowserve factory contact:

Nominal pump discharge <=350:
Flowserve Pumps
Flowserve GB Limited
Lowfield Works, Balderton
Newark, Notts NG24 3BU
United Kingdom

Telephone (24 hours) [phone]
Sales & Admin Fax [phone]
Repair & Service Fax [phone]
Email [e-mail]

Nominal pump discharge > 350:
Flowserve Pompes
13 rue Maurice Trintignant, CS10001
72234 Arnage Cedex, France

Telephone (24 hours) [phone]
Sales & Admin [phone]
Repair & Service Fax [phone]

Your local Flowserve representative:

North America:
Flowserve Pump Division
5310 Taneytown Pike, PO Box 91
Taneytown, MD 21787-0091, USA

Telephone [phone]
Customer Service Fax [phone]
Parts inquiry/order PH [phone]

South America:
Flowserve do Brasil Ltda
Av. Don Hélder Camara 5451
20771-001 Rio de Janerio, Brasil

Telephone [phone]
Fax [phone]

To find your local Flowserve representative please
use the Sales Support Locator System found at
www.flowserve.com

FLOWSERVE REGIONAL
SALES OFFICES:

USA and Canada

Flowserve Corporation
5215 North O’Connor Blvd.
Suite 2300
Irving, Texas 75039-5421, USA
Telephone: [phone]

Europe, Middle East, Africa
Flowserve Corporation
Parallelweg 13
4878 AH Etten-Leur
The Netherlands
Telephone: [phone]

Latin America
Flowserve Corporation
Martín Rodriguez 4460
B1644CGN-Victoria-San Fernando
Buenos Aires, Argentina
Telephone: [phone]
Telefax: [phone]

Asia Pacific
Flowserve Pte. Ltd.
10 Tuas Loop
Singapore 637345
Telephone: [phone]
Telefax: [phone]

Page 52 of 52 flowserve.com