Johnson Pump MCHZ User manual

Instruction Manual
MCHZ(S)
Horizontal self-priming multistage pump
Orginal instructions
Read and understand this manual prior to
operating or servicing this product.
MCHZ/EN (0912) 4.2

EC/EN (0911) 5.0 1
EC Declaration of conformity (valid until 30-12-2009)
(Directive 98/37/EC, appendix II-A)
Manufacturer
SPX Process Equipment NL B.V.
Dr. A.F. Philipsweg 51
P.O. B ox 9
9400 AA Assen
The Netherlands
hereby declares that the pump, in case it is delivered as an assembly with drive (last
position of serial number = A), is in conformity with the provisions of Directive 98/37/EC
(as altered most recently) and the following directives and standards:
• EC directive 2006/95/EG, "Electric equipment for use within certain voltage limits"
• standards EN-ISO 12100 part 1 & 2, EN 809
The pump to which this declaration refers may only be put into operation after it has been
installed in the way prescribed by the manufacturer, and, as the case may be, after the
complete system of which this pump forms part, has been made to fulfil the requirements
of Directive 98/37/EC (as altered most recently).
Manufacturer's declaration (valid until 30-12-2009)
(Directive 98/37/EC, appendix II-B)
Manufacturer
SPX Process Equipment NL B.V.
Dr. A.F. Philipsweg 51
P.O. B ox 9
9400 AA Assen
The Netherlands
hereby declares that the pump, in case it is delivered without drive (last position of serial
number = B), is in conformity with the following standards:
• EN-ISO 12100 parts 1 & 2, EN 809
and that this pump is meant to be incorporated in or combined with another machine
(electric motor, combustion engine) and may only be put into use after the complete
machine of which the pump under consideration forms part has been made and declared
to comply with that directive.
Assen, November 1st 2009
G.A. Schaafsma,
General manager

2EC/EN (0911) 5.0
EC Declaration of conformity (valid from 30-12-2009)
(Directive 2006/42/EC, appendix II-A)
Manufacturer
SPX Process Equipment NL B.V.
Dr. A.F. Philipsweg 51
9403 AD Assen
The Netherlands
hereby declares that all pumps member of productfamilies CombiBloc, CombiBlocHorti,
CombiChem, CombiDirt, CombiFlex(U)(B), CombiPrime H, CombiLine, CombiLineBloc,
CombiMag, CombiMagBloc, CombiNorm, CombiPro(M)(V), CombiPrime V, CombiSump,
CombiWell, FRE, FRES, FREF, FREM, KGE(L), KGEF, HCR, MCH(W)(S), MCHZ(W)(S),
MCV)(S), PHA, MDR whether delivered without drive (last position of serial number = B),
or delivered as an assembly with drive (last position of serial number = A), are in
conformity with the provisions of Directive 2006/42/EC (as altered most recently) and
where applicable the following directives and standards:
• EC directive 2006/95/EG, "Electric equipment for use within certain voltage limits"
• standards EN-ISO 12100 part 1 & 2, EN 809
The pumps to which this declaration refers may only be put into operation after they have
been installed in the way prescribed by the manufacturer, and, as the case may be, after
the complete system of which these pumps form part, has been made to fulfil the
requirements of Directive 2006/42/EC (as altered most recently).
Declaration of incorporation (valid from 30-12-2009)
(Directive 2006/42/EC, appendix II-B)
Manufacturer
SPX Process Equipment NL B.V.
Dr. A.F. Philipsweg 51
9403 AD Assen
The Netherlands
hereby declares that the partly completed pump (Back-Pull-Out unit), member of
productfamilies CombiBloc, CombiBlocHorti, CombiChem, CombiDirt, CombiFlex(U)(B),
CombiPrime H, CombiLine, CombiLineBloc, CombiMag, CombiMagBloc, CombiNorm,
CombiPro(M)(V), CombiPrime V, FRE, FRES, FREF, FREM, KGE(L), KGEF, HCR, PHA, MDR is
in conformity with the following standards:
• EN-ISO 12100 parts 1 & 2, EN 809
and that this partly completed pump is meant to be incorporated into the specified pump
unit and may only be put into use after the complete machine of which the pump under
consideration forms part has been made and declared to comply with that directive.
Assen, November 1st 2009
G.A. Schaafsma,
General Manager

MCHZ/EN (0912) 4.2 3
MCHZ
Instruction manual
MCHZ(S)
All technical and technological information in this manual as well as possible drawings
made available by us remain our property and shall not be used (otherwise than for the
operation of this pump), copied, duplicated, made available to or brought to the notice of
third parties without our prior written consent.
SPX Process Equipment NL B.V. (hereafter called Johnson Pump) is part of SPX
Process Equipment AB. The core activities of SPX Process Equipment AB are the
development, production, sale and maintenance of pumps and pump units.
SPX Process Equipment NL B.V.
P.O. B ox 9
9400 AA Assen
The Netherlands
Tel. [phone]
Fax. [phone]
www.johnson-pump.com or www.spxpe.com
© 2008 SPX Process Equipment NL B.V.

4MCHZ/EN (0912) 4.2

MCHZ/EN (0912) 4.2 5
MCHZ
Table of Contents
1 Introduction 9
1.1 Preface 9
1.2 Safety 9
1.3 Guarantee 10
1.4 Inspection of delivered items 10
1.5 Instructions for transport and storage 10
1.5.1 Dimensions and weight 10
1.5.2 Use of pallets 10
1.5.3 Hoisting 11
1.5.4 Storage 11
1.6 Ordering parts 12
2 General 13
2.1 Pump description 13
2.2 Applications 13
2.3 Type code 14
2.4 Serial number 14
2.5 Liquids 15
2.6 Construction 15
2.6.1 Pump section 15
2.6.2 Self-priming section 15
2.6.3 Impellers 15
2.6.4 Bearing construction 15
2.6.5 Shaft seal 16
2.7 Application area 16
2.8 Re-use 16
2.9 Scrapping 16
3Installation 17
3.1 Safety 17
3.2 Preservation 17
3.3 Environment 17
3.4 Piping 18
3.5 Accessories 18
3.6 Installation 19
3.6.1 Piping 19
3.6.2 Installation of a pump unit 19
3.6.3 Assembling a pump unit 19
3.6.4 Alignment of the coupling 19
3.6.5 Tolerances for aligning the coupling 20

6MCHZ/EN (0912) 4.2
3.7 Connection of the electric motor 20
4 Commissioning 21
4.1 Inspection of the pump 21
4.2 Inspection of the motor 21
4.3 Preparing the pump unit for commissioning 21
4.4 Checking the sense of rotation 21
4.5 Start-up 22
4.6 Adjustment of shaft sealing 22
4.6.1 Stuffing box packing 22
4.6.2 Mechanical seal 22
4.7 Pump in operation 22
4.8 Noise 22
5 Maintenance 23
5.1 Daily maintenance 23
5.2 Shaft sealing 23
5.2.1 Stuffing box packing 23
5.2.2 Mechanical seal 23
5.3 Environmental influences 23
5.4 Lubrication of the bearings 24
5.4.1 MCHZ(S) 12,5 - 14a/b (standard bearings) - 20a/b 24
5.4.2 MCHZ(S) 16 24
5.4.3 MCHZ(S) 14a/b with heavy bearing construction 24
5.5 Noise 24
5.6 Faults 24
6 Problem solving 25
7 Disassembly and assembly 27
7.1 Special tools 27
7.2 Precautionary measures 27
7.2.1 Switch off the power supply 27
7.2.2 Pipe support 27
7.2.3 Draining the liquid 27
7.3 Disassembling the MCHZ(S)12,5-14a/b-16 28
7.3.1 Replacing the stuffing box packing MCHZ 28
7.3.2 Replacing the mechanical seal MCHZS 29
7.3.3 Disassembling the pump 29
7.3.4 Disassembling the bearing housing on the drive side 29
7.3.5 Disassembly of the ball bearing 29
7.3.6 Disassembling the mechanical seal MCHZS 29
7.3.7 Disassembling the set of stage casings 30
7.3.8 Disassembling the bearing housing on the suction side 30
7.3.9 Disassembling the ball bearing on the suction side 30
7.3.10 Disassembling the mechanical seal on the MCHZS suction side 30
7.4 Assembly 31
7.4.1 Preparation for assembly 31
7.4.2 Sub-assembly of stage casings 31
7.4.3 Pump assembly 31
7.4.4 Assembling the stuffing box packing MCHZ 32
7.4.5 Assembling the mechanical seal MCHZS 32
7.4.6 Assembling the bearing construction 33
7.4.7 Assembling the stage set 34
7.5 Disassembling MCHZ(S) 14a/b heavy bearing construction 35
7.5.1 Replacing the stuffing box packing MCHZ 35

MCHZ/EN (0912) 4.2 7
MCHZ
7.5.2 Replacing the mechanical seal MCHZS 35
7.5.3 Disassembling the pump 35
7.5.4 Disassembling the bearing housing on the drive side 35
7.5.5 Disassembling the ball bearings 36
7.5.6 Disassembling the mechanical seal MCHZS 36
7.5.7 Disassembling the set of stage casings 36
7.5.8 Disassembling the bearing housing on the suction side 36
7.5.9 Disassembling the ball bearing on the suction side 36
7.5.10 Disassembling the mechanical seal on the MCHZS suction side 36
7.6 Assembling the MCHZ(S)14a/b heavy bearing construction 37
7.6.1 Preparation for assembly 37
7.6.2 Sub-assembly of stage casings 37
7.6.3 Pump assembly 37
7.6.4 Assembling the stuffing box packing MCHZ 37
7.6.5 Assembling the mechanical seal MCHZS 38
7.6.6 Assembling the bearing construction on the drive side 39
7.6.7 Assembling the stage set 40
7.6.8 Assembling the bearing construction on the suction side 40
7.7 Disassembling the MCHZ(S)20a/b 41
7.7.1 Replacing the stuffing box packing MCHZ 41
7.7.2 Replacing the mechanical seal MCHZS 41
7.7.3 Disassembling the MCHZ(S) 41
7.7.4 Disassembling the bearing housing on the drive side 41
7.7.5 Disassembly of the ball bearing 42
7.7.6 Disassembling the mechanical seal MCHZS 42
7.7.7 Disassembling the set of stage casings 42
7.7.8 Disassembling the bearing housing on the suction side 42
7.7.9 Disassembling the ball bearing on the suction side 42
7.7.10 Disassembling the mechanical seal on the MCHZS suction side 42
7.8 Assembling the MCHZ(S) 20a/b 43
7.8.1 Preparation for assembly 43
7.8.2 Sub-assembly of stage casings 43
7.8.3 Pump assembly 43
7.8.4 Assembling the stuffing box packing MCHZ 44
7.8.5 Assembling the mechanical seal MCHZS 44
7.8.6 Assembling the bearing construction 45
7.8.7 Assembling the stage set 46
8Dimensions 47
8.1 Dimensions MCHZ(S) 12,5 48
8.2 Dimensions MCHZ(S) 14a/b 49
8.3 Dimensions MCHZ(S) 16 50
8.4 Dimensions MCHZ(S) 20 51
8.5 Dimensions of unit MCHZ(S) 12,5 52
8.6 Dimensions of unit MCHZ(S) 14a 53
8.7 Dimensions of unit MCHZ(S) 14b 54
8.8 Dimensions of unit MCHZ(S) 16 55
8.9 Dimensions of unit MCHZ(S) 20a 56
8.10 Dimensions of unit MCHZ(S) 20b 57
9Parts 59
9.1 Ordering parts 59
9.1.1 Order form 59
9.1.2 Recommended spare parts 59
9.2 Designs 59

8MCHZ/EN (0912) 4.2
9.3 MCHZ 12,5 - 14a/b - 16 60
9.4 MCHZS 12,5 - 14a/b - 16 62
9.5 MCHZ 14a/b with heavy bearing construction 64
9.6 MCHZS 14a/b with heavy bearing construction 66
9.7 MCHZ 20a/b 69
9.8 MCHZS 20a/b 71
10 Technical data 73
10.1 Maximum speed 73
10.2 Permissible pressure and temperature 74
10.3 Hydraulic performance 75
10.3.1 Performance overview 3000 min-1 75
10.3.2 Performance overview 3600 min-1 76
10.4 Tightening moments for bolts and nuts 77
10.5 Tie rod torque 77
10.6 Post-greasing of ball bearings 77
10.7 Recommended locking liquids 77
10.8 Noise data 78
10.8.1 Pump noise as a function of pump power 78
10.8.2 Noise level of entire pump unit 79
Index 81
Order form for spare parts 83

MCHZ/EN (0912) 4.2 Introduction 9
MCHZ
1 Introduction
1.1 Preface
This manual is intended for technicians and maintenance staff and for those who are in
charge of ordering spare parts.
This manual contains important and useful information for the proper operation and
maintenance of this pump. It also contains important instructions to prevent potential
accidents and damage, and to ensure safe and fault-free operation of this pump.
! Read this manual carefully before commissioning the pump, familiarize
yourself with the operation of the pump and strictly obey the instructions!
The data published here comply with the most recent information at the time of going to
press. However they may be subject to later modifications.
Johnson Pump reserves the right to change the construction and design of the products
at any time without being obliged to change earlier deliveries accordingly.
1.2 Safety
This manual contains instructions for working safely with the pump. Operators and
maintenance staff must be familiar with these instructions.
Below is a list of the symbols used for those instructions and their meaning:
Personal danger for the user. Strict and prompt observance of the
corresponding instruction is imperative!
! Risk of damage or poor operation of the pump. Follow the corresponding
instruction to avoid this risk.
➢Useful instruction or tip for the user.
Items which require extra attention are shown in bold print.
This manual has been compiled by Johnson Pump with the utmost care. Nevertheless
Johnson Pump cannot guarantee the completeness of this information and therefore
assumes no liability for possible deficiencies in this manual. The buyer/user shall at all
times be responsible for testing the information and for taking any additional and/or
deviating safety measures. Johnson Pump reserves the right to change safety
instructions.

10 Introduction MCHZ/EN (0912) 4.2
1.3 Guarantee
Johnson Pump shall not be bound to any guarantee other than the guarantee accepted
by Johnson Pump. In particular, Johnson Pump will not assume any liability for explicit
and/or implicit guarantees such as but not limited to the marketability and/or suitability of
the products supplied.
The guarantee will be cancelled immediately and legally if:
• Service and/or maintenance is not undertaken in strict accordance with the
instructions.
• The pump is not installed and operated in accordance with the instructions.
• Necessary repairs are not undertaken by our personnel or are undertaken without our
prior written permission.
• Modifications are made to the products supplied without our prior written permission.
• The spare parts used are not original Johnson Pump parts.
• Additives or lubricants used are other than those prescribed.
• The products supplied are not used in accordance with their nature and/or purpose.
• The products supplied have been used amateurishly, carelessly, improperly and/or
negligently.
• The products supplied become defective due to external circumstances beyond our
control.
All parts which are liable to wear are excluded from guarantee. Furthermore, all
deliveries are subject to our “General conditions of delivery and payment”, which will be
forwarded to you free of charge on request.
1.4 Inspection of delivered items
Check the consignment immediately on arrival for damage and conformity with the advice
note. In case of damage and/or missing parts, have a report drawn up by the carrier at
once.
1.5 Instructions for transport and storage
1.5.1 Dimensions and weight
A pump or a pump unit is generally too heavy to be moved by hand. Therefore, use the
correct transport and lifting equipment. Dimensions and weight of the pump or pump unit
are shown on the label on the cover of this manual.
1.5.2 Use of pallets
Usually a pump or pump unit is shipped on a pallet. Leave it on the pallet as long as
possible to avoid damages and to facilitate possible internal transport.
! When using a forklift always set the forks as far apart as possible and lift the
package with both forks to prevent it from toppling over! Avoid jolting the
pump when moving it!

MCHZ/EN (0912) 4.2 Introduction 11
MCHZ
1.5.3 Hoisting
When hoisting a pump or complete pump units the straps must be fixed in accordance
with figure 1 and figure 2.
When lifting a pump or a complete pump unit always use a proper and sound
lifting device, approved to bear the total weight of the load!
Never go underneath a load that is being lifted!
! If the electric motor is provided with a lifting eye, this lifting eye is intended
only for the purpose of carrying out service activities to the electric motor!
The lifting eye is designed to bear the weight of the electric motor only!
It is NOT permitted to lift a complete pump unit at the lifting eye of an electric
motor!
1.5.4 Storage
If the pump is not to be used immediately the pump shaft must be turned by hand twice
per week.
Figure 1: Lifting instructions for pump unit.
Figure 2: Lifting instructions for single pump.

12 Introduction MCHZ/EN (0912) 4.2
1.6 Ordering parts
This manual contains a survey of the spare parts recommended by Johnson Pump as well
as the instructions for ordering them. A fax-order form is included in this manual.
You should always state all data stamped on the type plate when ordering parts and in
any other correspondence regarding the pump.
➢This data is also printed on the label on the front of this manual.
If you have any questions or require further information with regard to specific subjects,
then do not hesitate to contact Johnson Pump.

MCHZ/EN (0912) 4.2 General 13
MCHZ
2 General
2.1 Pump description
The MCHZ is a range of horizontal high-pressure stage pumps with closed impellers.
The range consists of the following 6 basic types:
• MCHZ 12,5
• MCHZ 14a
• MCHZ 14b
•MCHZ16
• MCHZ 20a
• MCHZ 20b
Each basic type can be designed with one or more pressure stages.
Flange dimensions, bolt circle and number of holes are according DIN 2535 ND 40.
The pump is driven by a standard IEC foot motor. The power is transmitted through a
flexible coupling.
Due to the modular design of the construction parts there is a high level of
interchangeability, even with other types of multistage pumps, such as the MCV or the
MCH.
2.2 Applications
The pump can be used for the following applications:
• warm and hot water supply systems.
• air-conditioning.
• cooling for land and marine installations.
• water supply for industry, water supply companies, agriculture and horticulture.
• spraying installations.
• washing and condensing installations.
• pressure increasing installations.
• in the process industry, general industry, road and marine construction.

14 General MCHZ/EN (0912) 4.2
2.3 Type code
Pumps are available in various designs. The main characteristics of the pump are shown
in the type code.
Examples: MCHZ 12,5 xn - 3,2 or MCHZS 20a xn - 8
2.4 Serial number
Serial number of the pump or pump unit are shown on the name plate off the pump and
on the label on the cover of this manual.
Pump family
MCHZ Multi stage Centrifugal Horizontal Z(Self-priming)
Shaft sealing
stuffing box packing
Smechanical seal
Impeller diameter
12,5
impeller diameter in cm
14
16
20
Impeller width
standard impeller
anarrow impeller
bwide impeller
Number of stages
nnumber of stages
n,7 n+1 impellers, of which the first has a reduced
diameter (70% of full diameter in this example)
Connections
3,2
diameter suction and pressure connection in cm
5
6,5
8
Example: 01-1000675A
01 year of manufacture
100067 unique number
5number of pumps
Apumpwithmotor
Bpump with free shaft end

MCHZ/EN (0912) 4.2 General 15
MCHZ
2.5 Liquids
In general the MCHZ pumps are suitable for pumping clean liquids, such as:
• spring water, cold and hot water.
• various cooling liquids.
• caustic soda.
• petrol, kerosene, petroleum.
These liquids must not affect the materials used. For the materials used see the
appropriate parts list in chapter 9.
We advise against using the pump for an application which differs from that
for which the pump was originally supplied, without discussing this with your
supplier first! Using a pump in a system or under system conditions (liquid,
system pressure, temperature, etc.) for which it has not been designed can
create danger for the user!
2.6 Construction
2.6.1 Pump section
The pump section is assembled from an inlet and outlet casing and a number of sections
or stage casings with cast vanes. The inlet and outlet casings are fitted with a cast
suction and pressure flange. The support for the inlet and outlet casings are in a vertical
centre line with the suction and the pressure pipes.
The inlet and outlet casings are fitted with connections for pressure gauge, balance pipe,
possible barrier liquid and drain.
By using guide blades the radial forces on the rotor can be disregarded over the entire
capacity curve.
The stage casings are fitted with exchangeable wear rings. To prevent turbulence and for
the benefit of the required NPSH values, there is a suction cover with 2 anti-rotation
partitions located in front of the first impeller.
2.6.2 Self-priming section
The self-priming section contains a built-in vacuum pump which operates according to
the liquid ring principle. Air or gas which is sucked in is discharged immediately via the
pressure pipe, provided there is no back-pressure.
2.6.3 Impellers
All types of MCHZ pumps, are fitted with closed impellers, designed with 2 sealing
edges and balance holes. As a result of this the axial forces on the rotor are reduced to a
minimum. The remaining forces are taken up by an axially mounted bearing. The impellers
are held on the shaft by 2 stainless steel external circlips.
2.6.4 Bearing construction
• All MCHZ pumps are designed with 2 grease-lubricated deep-groove ball bearings.
• For the types MCHZ 20a and 20b a double-row angular contact bearing is used on
the pressure side.
• Pumps with heavy bearing constructions - used for MCHZ 14a and 14b - are fitted
with 2 single-row angular contact bearings on the pressure side.
• MCHZ(S) 12,5, 14a/b (with standard bearings) and 20a/b are provided with 2RS1-
bearings.
• The MCHZ 16 and MCHZS 16 are fitted with grease nipples so that these bearings
can be greased periodically.
• The bearing housings are fitted with 2 holes so that the stuffing box is easy to access.

16 General MCHZ/EN (0912) 4.2
• The bearing on the pressure side is axially fixed.
• The bearing is sealed by means of rubber V-rings.
2.6.5 Shaft seal
The shaft seal for the MCHZ is available in 2 variants:
1MCHZ
Standardized stuffing box packing rings.
Pumps for which the pressure in the stuffing box becomes too high are designed with
a balance pipe.
2MCHZS
Mechanical seal with bellows
Cooling and lubrication of this seal is undertaken by circulation of the pumped liquid
via a balance pipe.
2.7 Application area
The application area globally looks as follows:
However, the maximum allowable pressures and temperatures depend strongly on the
selected materials and components. Also working conditions may cause differences. For
more detailed information see paragraph 10.2 "Permissible pressure and temperature".
2.8 Re-use
The pump may only be used for other applications after prior consultation with Johnson
Pump or your supplier. Since the lastly pumped medium is not always known, the
following instructions should be observed:
• Flush the pump properly
• Make sure the flushing liquid is discharged safely (environment!)
Take adequate precautions and use the appropriate personal protection
means (rubber gloves, spectacles)!
2.9 Scrapping
If it has been decided to scrap a pump, the same procedure as for paragraph 2.8 "Re-
use" should be followed.
Maximum value
Capacity 100 m3/h
Discharge head 340 m
Suction head 8 m (for water of 15°C and provided that air which is drawn
in is discharged without back-pressure)

MCHZ/EN (0912) 4.2 Installation 17
MCHZ
3Installation
3.1 Safety
• Read this manual carefully prior to installation and commissioning. Non-observance of
these instructions can result in serious damage to the pump and this will not be
covered under the terms of our guarantee. Follow the instructions given step by step.
• Ensure that the pump can not be started if work has to be undertaken to the pump
during installation and the rotating parts are insufficiently guarded.
• Depending on the design the pumps are suitable for liquids with a temperature of up
to 120°C. When installing the pump unit to work at 70°C and above the user should
ensure that appropriate protection measures and warnings are fitted to prevent
contact with the hot pump parts.
• If there is danger of static electricity, the entire pump unit must be earthed.
• If the pumped liquid is harmful to men or the environment, take appropriate measures
to drain the pump safely. Possible leakage liquid from the shaft seal should also be
discharged safely.
3.2 Preservation
In order to prevent corrosion, the inside of the pump is treated with a preserving agent
before leaving the factory. Before commissioning the pump remove any preserving
agents and flush the pump thoroughly with hot water.
3.3 Environment
• The foundation must be hard, level and flat.
• The area in which the pump is installed must be sufficiently ventilated. An ambient
temperature or air humidity which is too high, or a dusty environment, can have a
detrimental effect on the operation of the electric motor.
• There should be sufficient space around the pump unit to operate and if necessary
repair it.
• Behind the cooling air inlet of the motor there must be a free area of at least ¼ of the
electric motor diameter, to ensure unobstructed air supply.
• For models with a stuffing box, check that the gland nuts have not been over-
tightened. If necessary slacken the gland nuts and re-tighten them by hand.

18 Installation MCHZ/EN (0912) 4.2
3.4 Piping
• The piping to the suction and delivery connections must fit exactly and must not be
subject to stress during operation.
• The passage of the suction pipe must be amply dimensioned. This pipe should be as
short as possible and run towards the pump in such a way that no air pockets can
arise. If this is not possible, a venting facility should be provided at the highest point of
the pipe. If the inside diameter of the suction pipe is larger than the suction connection
of the pump, an eccentric reducer should be applied to prevent air pockets and whirls
See figure 3.
• The maximum allowable system pressure is stated in paragraph 10.2 "Permissible
pressure and temperature". If there is a risk that this pressure might be exceeded, for
instance because of an excessive inlet pressure, appropriate measures should be
taken by mounting a safety valve in the piping.
• Sudden changes in the rate of flow can lead to high pressure impulses in the pump
and the piping (water shock). Therefore, do not use quick-acting closing devices,
valves etc.
3.5 Accessories
• Fit any parts that may have been supplied separately.
• If the liquid does not flow towards the pump, fit a foot valve at the bottom of the
suction pipe. If necessary, combine this foot valve with a suction strainer to prevent
impurities from being drawn in.
• When mounting, place temporarily (for the first 24 operating hours) a fine gauze
between suction flange and suction pipe to prevent internal pump parts from being
damaged by foreign matter. If the risk of damage continues to exist, fit a permanent
filter.
Figure 3: Eccentric reducer to suction flange.

MCHZ/EN (0912) 4.2 Installation 19
MCHZ
3.6 Installation
3.6.1 Piping
Fit the gaskets between the flanges and connect the pressure and the suction pipes to
the pump.
3.6.2 Installation of a pump unit
Pump and motor shafts of complete pump units are adjusted perfectly in line in the
works.
1 In case of permanent arrangement place the base plate level on the foundation with
the aid of shims.
2 Carefully tighten the nuts on the foundation bolts.
3 Check the alignment of pump and motor shafts and if necessary realign, see
paragraph 3.6.4 "Alignment of the coupling".
3.6.3 Assembling a pump unit
If the pump and the electric motor still have to be assembled, do the following:
1 Fit both halves of the coupling to the pump shaft and the motor shaft respectively.
2 If the shaft height of the pump is not equal to the IEC size of the motor, level up the
difference by placing properly sized spacers under the pump or under the motor feet.
3 Place the pump on the base plate. Fix the pump to the base plate.
4 Place the electric motor on the base plate. Move the motor to obtain a gap of 3 mm
between both coupling halves.
5 Place copper shims under the feet of the electric motor. Fix the electric motor to the
base plate.
6 Align the coupling in accordance with the following instructions.
3.6.4 Alignment of the coupling
1 Place a ruler (A) on the coupling. Place or remove as many copper shims as is
necessary to bring the electric motor to the correct height so that the straight edge
touches both coupling halves over the entire length, see figure 4.
2 Repeat the same check on both sides of the coupling at the height of the shaft. Move
the electric motor so that the straight edge touches both coupling halves over the
entire length.
3 Check the alignment once again using a pair of external callipers (B) at 2 diametrical
opposite points on the sides of the coupling halves, see figure 4.
4 Fit the guard.
Figure 4: Aligning the coupling by means of a ruler and a pair of outside callipers.
B
A