Wright flow Classic+ User manual

I NSTALLATION , O PERATION
A ND
M AINTENANCE M ANUAL
F OR T HE
Range of Pumps

Page 2
Installation, Operation & Maintenance Manual
For The Classic+ Range Of Rotary Lobe Pumps
1.0
Safety Information. 5
1.1 Risk assessment relating to the use of Wright Flow Technologies Limited.
Classic+ rotary lobe pumps and pump units in potentially explosive
atmospheres. 8
2.0 Introduction. 9
2.1 General. 9
2.2 Wright Flow Technologies Limited Distributors. 9
2.3 Receipts and Storage. 9
2.4 Cleaning. 10
2.5 Pump Model Designation. 10
2.5.1 ATEX Information 11
2.5.2 Equipment Groups & Categories 11
2.6 Pump Model and Serial Number. 12
3.0 General. 14
3.1 Classic+ Pumping Principal. 14
3.2 Classic+ Range Operating Parameters. 15
3.3 System Design. 17
3.3.1 System Design and Installation. 17
3.3.2 Installations with CIP Systems. 19
3.4 Start Up Procedure. 20
3.5 Shutdown Procedure. 21
3.6 Routine Maintenance. 22
3.7 Heating and Cooling Jackets 22
3.8 Integral Pressure Relief Valves 25
3.8.1 Setting and Operating Spring Loaded Valves 26
3.8.2 Setting and Operating Air Loaded Integral Pressure Relief Valves 27
4.0 Classic+ Disassembly and Assembly. 30
4.1 CP10, CP20 and CP30 Pump - Disassembly and Assembly. 32
4.1.1 CP10, CP20 and CP30 Front Cover and Rotor Removal 32
4.1.2 CP10, CP20 and CP30 Rotorcase Removal 35
4.1.2.1 CP10, CP20 and CP30 Rotorcase Removal for Pumps fitted with Single Un-
Flushed Mechanical Seals and Single O-Ring Seals 35
4.1.2.2 CP10, CP20 and CP30 Rotorcase Removal for Pumps Fitted with Single
Flushed or Double Flushed Mechanical Seals. 37
4.1.3 CP10, CP20 and CP30 Gearbox Disassembly 38
4.1.3 CP10, CP20 and CP30 Gearbox Assembly 42
4.1.4 CP10, CP20 and CP30 Rotorcase, Rotor and Front Cover Assembly 46
4.2 CP40 Pumps - Disassembly and Assembly 48

Page 3
4.2.1
CP40 Front Cover and Rotor Removal 48
4.2.2 CP40 Rotorcase Removal 50
4.2.2.1 CP40 Rotorcase Removal for Pumps fitted with Single Un-flushed
Mechanical Seals and O-Ring Seals 50
4.2.2.2 CP40 Rotorcase Removal for Pumps Fitted with Single Flushed or Double
Flushed Mechanical Seals. 52
4.2.4 CP40 Gearbox Assembly 55
4.2.5 CP40 Rotorcase, Rotor and Front Cover Assembly 58
4.3 CP50 Pumps - Disassembly and Assembly 59
4.3.1 CP50 Front Cover and Rotor Removal 59
4.3.2 CP50 Rotorcase Removal 61
4.3.2.1 CP50 Rotorcase Removal for Pumps fitted with Single Un-flushed
Mechanical Seals and O-Ring Seals 61
4.3.2.2 CP50 Rotorcase Removal for Pumps fitted with Single Flushed and Double
Flushed Mechanical Seals 63
4.3.3 CP50 Gearbox Disassembly 64
4.3.4 CP50 Gearbox Assembly 66
4.3.5 CP50 Rotorcase, Rotor and Front Cover Assembly 69
5.0 Classic+ Mechanical Seal Removal & Replacement. 71
5.1 General Procedures for Installing Mechanical Seals. 71
5.2 CP10, CP20, CP30 and CP40 Mechanical Seals 72
5.2.1 CP10, CP20, CP30 and CP40 Single Mechanical Seal Removal 72
5.2.2 CP10, CP20, CP30 and CP40 Single Mechanical Seal Replacement 73
5.2.3 CP10, CP20, CP30 and CP40 Single Flushed Mechanical Seal Removal 74
5.2.4 CP10, CP20, CP30 and CP40 Single Flushed Mechanical Seal Replacement 75
5.2.5 CP10 Double Flushed Mechanical Seal Removal 76
5.2.6 CP10 Double Flushed Mechanical Seal Replacement 77
5.2.7 CP20, CP30 and CP40 Double Flushed Mechanical Seal Removal 78
5.2.8 CP20, CP30 and CP40 Double Flushed Mechanical Seal Replacement 79
5.3 CP50 Mechanical Seals 80
5.3.1 CP50 Single Mechanical Seal Removal 80
5.3.2 CP50 Single Mechanical Seal Replacement 80
5.3.3 CP50 Single Flushed Mechanical Seal Removal 81
5.3.4 CP50 Single Flushed Mechanical Seal Replacement 81
5.3.5 CP50 Double Flushed Mechanical Seal Removal 82
5.3.6 CP50 Double Flushed Mechanical Seal Replacement 83
6.0 Classic+ Single O-Ring Seals 84
6.1 General Procedures for Fitting Single O-Ring Seals 84
6.2 Oring Seals for CP10, CP20, CP30 and CP40 Pumps 85
6.2.1 CP10, CP20, CP30 and CP40 Oring Seal Assembly and Removal 85
6.3 O-Ring Seal for CP50 Pump 86
6.3.1 CP50 O-Ring Seal Assembly and Removal 86

Page 4
6.4
Classic+ Packed Gland Seals 87
6.4.1 General Procedures For Fitting Packed Gland Seals 87
6.5 Packed Gland Seals - CP10, CP20, CP30 and CP40 Series Pumps 88
6.5.1 Packed Gland Seal Removal 88
6.5.2 Packed Gland Seal Replacement 89
6.5.3 Flushed Packed Gland Seal Removal 89
6.5.4 Flushed Packed Gland Seal Replacement 90
6.6 Packed Gland Seals - CP50 Series Pumps. 91
6.6.1 Packed Gland Seal Removal 91
6.6.2 Packed Gland Seal Replacement 91
6.6.3 Flushed Packed Gland Seal Removal 92
6.6.4 Flushed Packed Gland Seal Replacement 93
6.6.5 Seal Conversion to Packed Gland (With Shaft Sleeve) 93
6.6.6 Seal Conversion to Flushed Packed Gland (With Shaft Sleeve) 94
7.0 Flushed Product Seals Auxiliary Services 95
7.1 Single Mechanical Seal (for Low-Pressure Quench or Flush) 95
7.2 Double Mechanical Seal (for High Pressure Flush) 96
7.3 Flushed Packed Gland Seal 96
8.0 Specifications 97
8.1 Clearance Chart 97
8.2 Fasteners & Torque Settings. 99
8.3 Lubricants. 100
8.4 Material Specifications. 100
8.5 Foundation Dimensions and Weights. 101
8.6 Rectangular Inlet 103
8.7 Trouble Shooting. 104
8.8 Typical Noise Emission Data - CP10, CP20 and CP30 Pumps. 105
8.9 Typical Noise Emission Data – CP40 and CP50 Pumps. 106
8.10 Service History. 107
8.11 Tool List. 108
9.0 Notes. 110

Page 5
1.0 Safety Information.
INCORRECT INSTALLATION, OPERATION, OR MAINTENANCE OF
EQUIPMENT MAY CAUSE SEVERE PERSONAL INJURY OR DEATH
AND/OR EQUIPMENT DAMAGE AND MAY INVALIDATE THE WARRANTY.
THIS INFORMATION MUST BE READ FULLY BEFORE BEGINNING
INSTALLATION, OPERATION, OR MAINTENANCE AND MUST BE KEPT
WITH THE PUMP. SUITABLY TRAINED OR QUALIFIED PERSONS MUST
UNDERTAKE ALL INSTALLATION AND MAINTENANCE ONLY.
DANGER
DO NOT OPERATE PUMP IF:
- The front cover is not installed correctly.
- Any guards are missing or incorrectly installed.
- The suction or discharge piping is not connected.
DO NOT place fingers, etc. into the pumping chamber or its connection ports
or into any part of the gearbox if there is ANY possibility of the pump shafts
being rotated. Severe injury will occur.
DO NOT exceed the pumps rated pressure, speed, and temperature, or
change the system/duty parameters from those for which the pump was
originally supplied, without confirming its suitability for the new duty. Running
of the pump outside of its operation envelope can cause mechanical contact,
excessive heat and can represent a serious risk to health and safety.
Installation and operation of the pump must always comply with health and
safety regulations.
A device must be incorporated into the pump, system, or drive to prevent the
pump exceeding its stated duty pressure. It must be suitable for both
directions of pump rotation where applicable. Do not allow pump to operate
with a closed/blocked discharge unless a pressure relief device is
incorporated. If an integral relief valve is incorporated into the pump, do not
allow re-circulation through the relief valve for extended periods (refer to
section 3.8).
Warning - Safety instructions which
shall be considered for reasons of safe
operation of the pump or pump unit
and/or protection of the pump or pump
unit itself are marked by the sign:
WARNING
Danger - Failure to follow the listed
precautionary measures may result
in serious injury or death are
identified by the following symbol:
WARNING

Page 6
The mounting of the pump or pump unit should be solid and stable.
Pump orientation must be considered in relation to drainage/cavity
ventilation requirements. Once mounted, shaft drive elements must be
checked for correct alignment. Rotate pump shaft by at least one full
revolution to ensure smoothness of operation. Incorrect alignment will
produce excessive loading and will create high temperatures and
increased noise emissions. It may also be necessary to earth the pump
head to avoid the build up of a potential charge difference that could
cause a spark.
The installation must allow safe routine maintenance and inspection (to
replenish lubricants, check for leakage, monitor pressures, etc) and provide
adequate ventilation necessary to prevent overheating.
Fill all gearboxes with the recommended grades and quantities of lubricant
(refer to section 3.4 and 8.3). Beware of over/under filling the gearbox as this
could cause the pump to overheat and mechanical damage to occur.
Before operating the pump, be sure that it and all parts of the system to which
it is connected are clean and free from debris and that all valves in the suction
and discharge pipelines are fully opened. Ensure that all piping connecting to
the pump is fully supported and correctly aligned with its relevant connections.
Misalignment and/or excess loads will cause severe pump damage. This
could result in unexpected mechanical contact in the pump head and has the
potential to be an ignition source.
Be sure that pump rotation is correct for the desired direction of flow (refer to
section 3.4).
Do not install the pump into a system where it will run dry (i.e. without a supply
of pumped media) unless it is equipped with a flushed shaft seal arrangement
complete with a fully operational flushing system. Mechanical seals require a
thin fluid film to lubricate the seal faces. Dry running can cause excessive heat
and seal failure.
Pressure gauges/sensors are recommended, next to the pump suction and
discharge connections to monitor pressures.
Caution must be taken when lifting the pump. Suitable lifting devices should
be used as appropriate. Lifting eyes installed on the pump must only be used
to lift the pump, not pump with drive and/or base plate. If pump is base plate
mounted, the base plate must be used for all lifting purposes. If slings are
used for lifting, they must be safely and securely attached. For weights of bare
shaft pumps refer to section 8.5.
WARNING
WARNING
WARNING
WARNING
WARNING

Page 7
DO NOT attempt any maintenance or disassembly of the pump or pump unit
without first ensuring that:
-The pump is fully isolated from the power source (electric, hydraulic,
pneumatic).
- The pumping chamber, pneumatic relief valve and any shaft seal
support system are depressurised and purged.
- Any temperature control devices (jackets, heat-tracing, etc) are fully
isolated, that they are depressurised and purged, and components are
allowed to reach a safe handling temperature.
DO NOT attempt to dismantle a pressure relief valve, which has not
had the spring pressure relieved, is still connected to a pressurised
gas/air supply or is mounted on a pump that is operating. Serious
personal injury or death and/or pump damage may occur.
DO NOT loosen or undo the front cover, any connections to the pump, shaft
seal housings, temperature control devices, or other components, until sure
that such action will not allow the unsafe escape of any pressurised media.
Pumps and/or drives can produce sound power levels exceeding 85-dB (A)
under certain operating conditions. When necessary, personal protection
against noise must be taken. Typical noise emission data can be found in
section 8.8 and 8.9.
Avoid any contact with hot parts of pumps and/or drives that may cause injury.
Certain operating conditions, temperature control devices (jackets, heat-
tracing, etc.), bad installation, or poor maintenance can all promote high
temperatures on pumps and/or drives.
When cleaning, either manually or by CIP method, the operator must ensure
that a suitable procedure is used in accordance with the system requirements.
During a CIP cleaning cycle, a pump differential pressure of between 2 and 3
bar (30 and 45 psi) is recommended to ensure suitable velocities are reached
within the pump head. The exterior of the pump should be cleaned
periodically.
Surface temperature of pump is also dependent on the temperature of
pumped medium.
WARNING

Page 8
1.1 Risk assessment relating to the use of Wright Flow Technologies Limited.
Classic+ rotary lobe pumps and pump units in potentially explosive
atmospheres.
Source Of Hazards Potential Hazards
Frequency Of
Hazards Recommended Measures
Unvented cavities Build up of explosive gas
Very Rare
Ensure that pump is totally filled.
Consider mounting ports vertically.
See Chapter 1.0
Rotorcase / Rotors / Front
Cover Unintended mechanical contact
Rare
Ensure that operating pressures are
not exceeded. Ensure that suffcient
NPSH to prevent cavitation. See
Chapter 1.0/3.3.1 Service plan.
Pump external surfaces excess temperature.
Electrostatic charging
Rare
User must ensure temperature limits.
Do not overfill gearboxes with
lubricant. Provide a ground contact
for pump. See Chapter 1.0 /
Service
plan.
Cover 'O' ring
Pump liquid leakage. Build
up of explosive gas.
Very Rare
Check selection of elastomers are
suitable for application. Ensure cover
retaining nuts are tight. Service plan.
Pump casing / cover
Pump liquid leakage. Build
up of explosive gas.
Very Rare
Stainless steel, Corrosion resistant.
Shaft seals
excess temperature.
Unintended mechanical
contact.
Leakage.
Build up of explosive gas.
Rare
Selection of seal system must be
suitable for application.
See Chapter
5.0. Service plan. Seals must never
run dry.
Auxiliary system for shaft
sealing
Pump liquid leakage. Build
up of explosive gas.
Rare
Selection of auxiliary seal system
must be suitable for application.
Seals must never run dry.
Rotation direction test Excess temperature
Very Rare
If flushed seals are installed ensure
that flush is applied to seal
assemblys. Only allow pump to run
for minimum period - just a few
seconds.
Closed valve condition Excess Temperature. Excess Pressure.
Mechanical contact.
Rare
Can cause excessive pressue, heat
and mechanical contact. See
Chapter 1.0
Shaft Random induced current
Very Rare
Provide a ground contact for pump.
See Chapter 1.0.
Mechanical shaft coupling
(Torque Protection)
Temperature from friction
Sparks from break up of
shear pins.
Electrostatic charging
Rare
Coupling selection must suit
application. See Chapter 1.0.
Mechanical shaft coupling
(standard)
Break up of spider.
Unintended mechanical
contact.
Electrostatic charging
Rare
Coupling selection must suit
application. Service plan. See
Chapter 1.0.
Note:- For a feature to be suitable for an application, The feature must be fit for its
designated purpose and also suitable for the environment where it is to be installed.

Page 9
2.0 Introduction.
2.1 General.
Classic+ rotary lobe pumps are manufactured by Wright Flow Technologies
Limited, a unit of the IDEX Corporation.
This manual includes all the necessary information for the Classic+ and
should be read prior to beginning installation, operation, or
maintenance.
Should you require any additional information regarding the Classic+
contact Wright Flow Technologies Limited or their local authorised
distributor, refer to section 2.2.
When asking for assistance please provide the pump model and serial
number. This information can be obtained from the pump nameplate
which is located on the side of the pump gearbox cover, refer to section
2.6.
Should the nameplate be unreadable or missing, the serial number is also
stamped on either side of the rotorcase refer to section 2.6.
If the system or product characteristics are to be changed from the
original application for which the pump was selected, Wright Flow
Technologies Limited or their authorised distributor should be consulted
to ensure the pump is suitable for the new application.
2.2 Wright Flow Technologies Limited Distributors.
Wright Flow Technologies Limited distributes its products internationally
via a network of authorised distributors. Throughout this manual where
reference is made to Wright Flow Technologies Limited, service and
assistance will also be provided by any Wright Flow Technologies
Limited authorised distributor for Classic+.
2.3 Receipts and Storage.
Upon receipt of the pump, immediately examine it for any signs of
visible damage. If any damage is noted, contact Wright Flow
Technologies Limited or your Wright Flow Technologies Limited
distributor and clearly mark upon the carriers’ paperwork that the goods
have been received in a damaged condition, with a brief description of
damage.

Page 10
If the pump is not required for immediate installation then it should be
stored in a clean, dry environment. It is recommended that storage
temperature should be between –10°and 40°C (14°F and 105°F).
Further to the above, if the pump is not intended for installation or use within
18 months or more then refer to Wright Flow Technologies Limited, or the
Wright Flow Technologies Limited authourised distributor for storage
recommendations.
2.4 Cleaning.
The Classic+ pump series is suitable for both manual cleaning and CIP
(Cleaning In Place), refer to section 3.3.2.
It is recommended that the exterior of the pump be cleaned periodically with a
non-aggressive, non-abrasive cleaning solution.
2.5 Pump Model Designation.
The designations of pump models in the Classic+ range are as follows:
CP10/0005/12 CP20/0020/12 CP30/0069/12 CP40/0180/12 CP50/0351/12
CP10/0008/08 CP20/0031/07 CP30/0113/07 CP40/0250/07 CP50/0525/08
CP10/0011/05
This information, together with the pump serial number, should be
provided when requesting additional information on the pump or when
ordering spare parts. The pump serial number is stamped on the pump
nameplate and the rotorcase, (refer to section 2.6, Figs 2 and 3).
For the maximum operating pressures, temperatures and speeds refer
to section 3.2, Fig 6.
Fig 1 CP designated models only.
CP
30
0069
12
/
/
P UMP
R
ANGE
D ISPLACEMENT
( LTRS / REV )
M ODEL
S
IZE
M AX
P
RESSURE
(
B
AR
)

Page 11
2.5.1 ATEX Information
ATEX Pump Requirements
Please be aware that mechanical seals are a source of heat and must never be
allowed to run dry. We would recommend provision be made to ensure that there is
a flow of fluid around the pump seals at all times. If there is a risk of the supply
being interrupted, we would recommend that the flush on the seals be fitted with a
flow detection device. The surface temperature of the pump is dependent on the
temperature of the pumped fluid and due account of this should be taken whilst
undertaking your risk assessment of the installation. These pumps are rated to T3.
2.5.2 Equipment Groups & Categories
TEMP - T3
SERIAL NO:
ex II - 2 - G/D
Group
II.
Category
Unit is suitable for
environments containing
dust or gas
Temperature Class.

Page 12
2.6 Pump Model and Serial Number.
Should you require any information regarding your Classic+ rotary lobe
pump contact Wright Flow Technologies Limited or your Wright Flow
Technologies Limited distributor, providing the pump model and serial
number as stated on the pump nameplate, see Fig 2, which is fixed to
the pump gearbox cover.
Should this be damaged or missing, the pump serial number is also stamped
on opposite corners of the rotorcase or on the rear face of the rotorcase, (see
Fig 3).
Fig 2 Nameplate
Fig 3 Serial Number Position on Rotorcase
12345/A/67
12345/A/67
Or

Page 13
2.7 Standard Pump Component Terms.
ROTORS
FRONT COVER
ROTOR RETAINER
ROTORCASE BEARING
HOUSING FRONT
BEARINGS GEARBOX
COVER BREATHER
/FILLER CAP
REAR BEARINGS
DRIVE
SHAFT
DRIVEN
SHAFT
TIMING
GEARS
Fig 4 Pump Component Terms

Page 14
3.0 General.
3.1 Classic+ Pumping Principal.
The pumping action of the rotary lobe pump principle is generated by the
contra rotation of two pumping elements (rotors) within a chamber (rotorcase)
- see Fig 5. The rotors are located on shafts, which in turn are mounted within
an external gearbox and supported by the bearings; the timing gears are also
located on the shafts. The timing gears transfer the energy from the drive
shaft to the driven shaft, synchronising the rotors such that they rotate without
contact with each other.
As the rotors pass the suction port, see Fig 5a, the cavity generated increases
creating a pressure decrease, which induces the pumped medium to flow into
the rotorcase.
The pumped medium is carried around the rotorcase by the rotors; see Fig 5b
and 5c, to the discharge side of the pump, Fig 5d. Here the cavity decreases
and the pumped medium is discharged from the rotorcase, Fig 5e.
For pump component terms see Fig 4.
Fig 5 Rotary Lobe Pumping Principle.

Page 15
3.2 Classic+ Range Operating Parameters.
The maximum pressure and speed operating parameters are given in Fig 6. In
practice these may be limited due to the nature of the product to be pumped
and/or design of the system in which the pump is to be installed. Consult
Wright Flow Technologies Limited or your Wright Flow Technologies Limited
distributor for assistance.
The operating temperature limit of the pump is determined by the rotor
clearance. For the CP10, CP20, CP30 and CP40 series pumps there are
three rotor clearance bands (class A, B and C), and two (class B and D) for
the CP50 series pumps.
If the system or product characteristics are to be changed from the original
application for which the pump was selected, Wright Flow Technologies
Limited or their authorized distributor should be consulted to ensure the pump
is suitable for the new application.
The pump should not be subjected to sudden temperature changes to avoid
the risk of damage from sudden expansion/contraction of components. Care
should be taken when selecting pumps for handling liquids containing
abrasive particles as these may cause wear of pump head components. For
advice or assistance contact Wright Flow Technologies Limited or your Wright
Flow Technologies Limited distributor.
WARNING

Page 16
Classic+ Series Operating Temperature Limit (°C)
Class A Class B Class C Class D
CP10, 20, 30, 40 70 100 150 N/A
CP50 N/A 100 N/A 180
N/A = Not Available
Fig 6 Operating Parameters
Pump Range Theoretical Displacement Nominal Connection
Size
Max Diff.
Pressure Max. Speed
Max
Speed @
Max Diff.
Pressure
Max Diff.
Pressure @
Max Speed
ltr/rev Imp.gal
/100 rev US gal /100 rev mm inches bar psi rev/min rev/min bar psi
CP10/0005/12 0.046 1.01 1.22 25 1 12 175 1400 1000 8.5 120
CP10/0008/08 0.083 1.83 2.19 38 1.5 8 120 1400 1000 5.5 75
CP10/0011/05 0.111 2.44 2.93 38 1.5 5 70 1400 1000 3.5 50
CP20/0020/12 0.202 4.44 5.34 38 1.5 12 175 1000 750 8.5 120
CP20/0031/07 0.313 6.89 8.27 50 2 7 100 1000 750 5.0 70
CP30/0069/12 0.694 15.27 18.34 50 2 12 175 750 550 8.5 120
CP30/0113/07 1.125 24.75 29.72 76 3 7 100 750 550 5.0 70
CP40/0180/12 1.800 39.60 47.56 76 3 12 175 700 520 8.5 120
CP40/0250/07 2.500 55.00 66.05 101 4 7 100 700 520 5.0 70
CP50/0351/12 3.514 77.31 92.84 101 4 12 175 650 420 8.5 120
CP50/0525/08 5.250 115.50 138.70 152 6 8 115 600 420 5.5 75
CP20/CP30 High Efficiency Operating Parameters.
CP20/0020/07 0.202 4.44 5.34 38 1.5 7 100 1000 750 5.0 70
CP20/0031/04 0.313 6.89 8.27 50 2 4 55 1000 750 3.0 40
CP30/0069/07 0.694 15.27 18.34 50 2 7 100 750 520 5.0 70
CP30/0113/04 1.125 24.75 29.72 76 3 4 55 750 520 3.0 40

Page 17
3.3 System Design.
3.3.1 System Design and Installation.
When incorporating any pump into a system it is considered good practice to
minimize piping runs and the number of pipe fittings (tees, unions, bends etc.)
and restrictions. Particular care should be taken in designing the suction line,
which should be as short and straight as possible with a minimum of pipe
fittings to minimise restricting product flow to the pump. The following should
be considered at the design stage of any system
Be sure ample room is provided around the pump to allow for:
−Access to the pump and drive for routine inspection and maintenance, i.e.
to remove pump front cover and rotors.
−Ventilation of the drive to prevent over heating.
The exterior of the pump unit may exceed 68°C (154°F),
Appropriate measures must be taken to warn or protect operators.
The pump must not be used to support piping. All piping to and from the pump
unit must be independently supported. Failure to observe this may distort the
pump head components or assembly and cause serious consequential
damage to the pump.
Valves should be provided adjacent to the pump suction and discharge
connections to allow the pump to be isolated from the system for routine
inspection and maintenance.
Rotary lobe pumps are of the positive displacement type and therefore an
overload protection device must be provided. This can take the form of:
−An in-line pressure relief system, i.e. external to the pump.
−Incorporation of a torque-limiting device in the drive system.
It is recommended that all piping and associated equipment from the tank to
the discharge point is thoroughly cleaned before installation of the pump to
avoid the possibility of debris entering the pump and causing damage.
Pressure gauges should be installed adjacent to the pump suction and
discharge connections such that system pressures can be monitored. These
gauges will provide a clear indication of changes in operating conditions and
where a relief valve is incorporated in the system, will be necessary for setting
and checking the functioning of the valve.
It is imperative that the suction condition at the pump inlet meets the Net
Positive Suction Head required (NPSHr) by the pump. Failure to observe this
could cause cavitation, resulting in noisy operation, reduction in flow rate and
mechanical damage to the pump and associated equipment.
WARNING
WARNING
WARNING
WARNING

Page 18
The Net Positive Suction Head available (NPSHa) from the system must
always exceed the Net Positive Suction Head required (NPSHr) by the pump.
Observing the following general guidelines should ensure the best possible
suction condition is created.
−Suction piping is at least the same diameter as the pump connections.
−The length of suction piping is kept to the absolute minimum.
−The minimum number of bends, tees and pipework restrictions are used.
−Calculations to determine system NPSHa are carried out for the worst
condition see below.
Should advice on pump or system NPSH characteristics be required contact
the factory or their authorised distributor.
10.0 Meters (32.8 Feet) Water Column
Suction Lift
Or Vacuum
Atmospheric
Pressure
Suction
Head
NPSH
Available
Suction Line
Friction Loss
Vapour
Pressure
NPSH
Available
Suction Line
Friction Loss
Vapour
Pressure
For Suction Lift
Or Vacuum
Conditions.
For Conditions
With Positive
Suction Head.
Atmospheric
Vacuum
Fig 7 NPSH
WARNING

Page 19
When installing a pump complete with base plate, motor and drive, the following
guidelines must be observed:
a) The preferred drive arrangement for any rotary lobe pump is in-line
direct coupled. If an alternative is required please contact Wright Flow
Technologies Limited or your Wright Flow Technologies Limited
distributor.
b) Flexible couplings must always be incorporated and correctly aligned
within the limits recommended by the coupling manufacturer. To
check coupling alignment rotate the shaft by at least one full revolution
and ensure that the shaft rotates smoothly.
Couplings of a non-flexible design must never be used.
c) Couplings must always be enclosed in a suitable guard to prevent
contact with rotating parts, which could result in personal injury.
Guards should be of suitable material, (see d) and of sufficiently rigid
design to prevent contact with rotating parts under normal operating
conditions.
d) When the pump is installed in a flammable or explosive environment,
or is used for handling flammable or explosive materials, special
consideration must be given. Not only to the safety aspects of the
drive unit enclosure but also to the materials used for both the
coupling and the guard to eliminate the risk of explosion.
e) Base plates must be secured to a flat level surface such that distortion
and misalignment are avoided. Once base plates are fastened in
position the drive alignment must be re-checked, (see b).
f) When using electric motor drives, ensure that the electrical supply is
compatible with the drive and controls and that the method of wiring is
correct for the type of starting required by the motor i.e. Direct On
Line, or other similar method. Ensure all components are correctly
grounded.
3.3.2 Installations with CIP Systems.
The Classic+ pump range is designed to be effectively cleaned by the CIP
procedures recommended for in place cleaning of process plant. It is
recommended that a differential pressure of 2 to 3 Bar (30 to 45 psi) be
developed across the pump head during cleaning in order to develop the
necessary fluid velocities required for thorough cleaning.

Page 20
3.4 Start Up Procedure.
- Check that all piping and associated equipment are clean and free from
debris and that all pipe connections are secure and leak free.
- For pumps fitted with flushed product seals check all auxiliary services
are in place and connected and provide sufficient flow and pressure for
flushing purposes, refer to section 7.0.
- Ensure lubrication is provided for both pump and drive. The Classic+ is
shipped without oil as standard and should be filled to the level of the
oil sight glass - refer to section 8.3 for pump oil capacities and grades.
- If an external relief valve is incorporated in the system, check that it is set
correctly. For start up purposes, it is considered good practice to set the
relief valve lower than the system design pressure. On completion of
start up, the relief valve should be reset to the required setting for the
application. The required setting should never exceed the lower of either
the pumps maximum pressure rating or the system design pressure. For
setting integral relief valves refer to sections 3.8.1 and 3.8.2.
- Be sure both suction and discharge valves are fully opened and that pipe
work is free from all obstructions. The Classic+ is a positive displacement
type pump and should therefore never be operated against a closed
valve as this would result in pressure overload, resulting in damage to
the pump and possibly the system.
- Make sure that the drive shaft rotation is correct for the direction of flow
required. See Fig 8.
WARNING
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