KRAL OMS Series User manual

Operating instructions
KRAL flowmeters.
Series OMS
Low-viscosity liquids
OIO 30en-GB
Edition 2019-04
Original instructions
www.kral.at

Table of contents
1 About this document ..................................................... 4
1.1 General information .......................................................4
1.2 Target groups ................................................................4
1.3 Symbols.........................................................................4
1.3.1 Danger levels ....................................................4
1.3.2 Danger signs.....................................................5
1.3.3 Symbols in this document .................................5
1.4 Associated documents ..................................................5
2 Safety .............................................................................. 6
2.1 Proper use .....................................................................6
2.2 Foreseeable misuse ......................................................6
2.3 Obligations of the operator-owner .................................6
2.4 Dangers during transportation .......................................7
2.5 Dangers during storage .................................................7
2.6 Dangers during installation ............................................7
2.7 Dangers during removal ................................................7
2.8 Dangers during connection work ...................................7
2.9 Dangers during operation ..............................................7
2.10 Dangers during servicing...............................................8
2.11 Dangers during disposal................................................8
3 Identification................................................................... 9
3.1 Type code......................................................................9
3.2 Rating plate .................................................................10
4 Technical data .............................................................. 10
4.1 Operating limits............................................................10
4.2 Pressure pulsation.......................................................10
4.3 Maximum values..........................................................10
4.4 Substitute operating data.............................................11
4.5 Sound pressure level...................................................11
4.6 Dimensions and weights..............................................12
4.6.1 Pipe thread (BSPP thread) .............................12
4.6.2 DIN flange .......................................................12
4.7 Pressure bearing capacity ...........................................13
4.7.1 Pressure bearing capacity OMS-020 ..............13
4.7.2 Pressure bearing capacity OMS-032 ..............14
4.7.3 Pressure bearing capacity OMS-052 ..............15
5 Function description.................................................... 16
5.1 Structure ......................................................................16
5.2 Functional principle......................................................16
5.3 Rolling bearings...........................................................16
5.4 Signal generation.........................................................17
5.5 Linearization ................................................................17
5.6 Temperature compensation.........................................17
5.7 Recognition of flow direction........................................17
6 Transportation, storage............................................... 18
6.1 Dangers during transportation .....................................18
6.2 Dangers during storage ...............................................18
6.3 Unpacking and checking the state of delivery .............18
6.4 Transporting flowmeters ..............................................18
6.5 Storing the flowmeter...................................................19
6.6 Preservation ................................................................19
6.6.1 Preservation table ...........................................19
6.6.2 Preserving the inner surfaces .........................20
6.6.3 Preserving the outer surfaces .........................20
6.6.4 Removing the preservation .............................20
7 Installation, removal......................................................21
7.1 Dangers during installation ..........................................21
7.2 Dangers during removal...............................................21
7.3 Installing the flowmeter ................................................21
7.3.1 Protecting the flowmeter against soiling ..........21
7.3.2 Installation types..............................................22
7.3.3 Installation recommendation............................23
7.3.4 Installing the flowmeter....................................24
7.4 Removing the flowmeter ..............................................24
8 Connection.....................................................................25
8.1 Dangers during connection work .................................25
8.2 Connecting the flowmeter to the pipe system ..............25
8.3 Connecting the pick up ................................................26
9 Operation........................................................................26
9.1 Dangers during operation ............................................26
9.2 Commissioning ............................................................26
9.2.1 Cleaning the pipe system ................................26
9.2.2 Checking the function ......................................27
9.2.3 Commissioning the flowmeter .........................27
9.3 Decommissioning.........................................................28
9.3.1 Switching off the flowmeter..............................28
9.4 Recommissioning.........................................................28
9.4.1 Recommissioning the flowmeter......................28
10 Maintenance...................................................................29
10.1 Required maintenance.................................................29
10.2 Maintaining flowmeters ................................................29
10.3 Recalibration of the flowmeter .....................................29
11 Servicing ........................................................................30
11.1 Dangers during servicing .............................................30
11.2 Replacing seals and bearings......................................30
11.2.1 Removing seals and bearings OMS-020/
OMS-032 .........................................................30
11.2.2 Installing seals and bearings OMS-020/
OMS-032 .........................................................31
11.2.3 Removing seals and bearings OMS-052.........32
11.2.4 Installing seals and bearings OMS-052...........34
12 Disposal..........................................................................35
12.1 Dangers during disposal ..............................................35
12.2 Dismantling and disposing of the flowmeter ................35
13 Troubleshooting ............................................................36
13.1 Possible faults..............................................................36
13.2 Troubleshooting ...........................................................36
14 Spare parts.....................................................................38
14.1 Spare parts ..................................................................38
15 Accessories ...................................................................40
15.1 Heating.........................................................................40
15.1.1 Possible types of heating.................................40
15.1.2 Technical data of the electrical heating system
.........................................................................41
15.1.3 Technical data of the fluid heating system ......41
15.1.4 Installing the heating system ...........................41
15.2 Junction box.................................................................43
15.2.1 Function description ........................................43
15.2.2 Technical data .................................................43
15.2.3 Installing the junction box ................................43
2OIO 30en-GB Edition 2019-04 Operating instructions

Table of contents
15.3 Extension cable ...........................................................44
15.3.1 Function description........................................44
15.3.2 Technical data.................................................44
15.3.3 Connecting the extension cable......................44
16 Appendix....................................................................... 45
16.1 Tightening torque for screws with metric screw threads
and head contact surfaces ..........................................45
16.2 Tightening torques for screw plugs with thread meas-
ured in inches and elastomer seal...............................46
16.3 Tightening torques and widths for threaded rings .......46
16.4 Contents of the Declaration of Conformity...................46
Operating instructions OIO 30en-GB Edition 2019-04 3

1 About this document
1.1 General information
1 About this document
1.1 General information
These instructions form part of the product and must be kept for future reference. Furthermore please
observe the associated documents.
1.2 Target groups
The instructions are intended for the following persons:
oPersons who work with the product
oOperator-owners who are responsible for the use of the product
Information on the required qualification of the personnel is provided separately at the beginning of the
individual chapters in these instructions. The following table provides an overview.
Target group Activity Qualification
Transport per-
sonnel
Transportation,
unloading
Transport personnel are qualified personnel who carry out the trans-
portation of products properly due to their training, knowledge and
experience and on the basis of the relevant provisions. Transport
personnel recognize and avoid possible dangers and damage to
property that are connected with this activity.
Mobile crane
operators,
crane operat-
ors, forklift oper-
ators
Unloading, pos-
itioning
Mobile crane operators, crane operators and forklift operators are
qualified personnel who carry out work with cranes and forklifts
properly due to their training, knowledge and experience and on the
basis of the relevant provisions. Mobile crane operators, crane op-
erators and forklift operators recognize and avoid possible dangers
and damage to property that are connected with this activity.
Fitter Mounting, con-
nection
Fitters are qualified personnel who carry out the mounting work
properly due to their training, knowledge and experience and on the
basis of the relevant provisions. Fitters recognize and avoid pos-
sible dangers and damage to property that are connected with this
activity.
Electrician Electrical con-
nection
Electricians are qualified personnel who carry out work on electrical
equipment and installations properly due to their training, know-
ledge and experience and on the basis of the relevant provisions.
Electricians recognize and avoid possible dangers and damage to
property that are connected with this activity.
Trained person-
nel
Delegated task Trained personnel were instructed by the operator-owner in the task
delegated to them and the possible dangers arising through im-
proper behaviour.
Tab.1: Target groups
1.3 Symbols
1.3.1 Danger levels
Signal word Danger level Consequences of non-observance
DANGER Immediate threat of danger Serious personal injury, death
WARNING Possible threat of danger Serious personal injury, invalidity
CAUTION Potentially dangerous situation Slight personal injury
ATTENTION Potentially dangerous situation Material damage
4OIO 30en-GB Edition 2019-04 Operating instructions

1 About this document
1.4 Associated documents
1.3.2 Danger signs
Meaning Source and possible consequences of non-observance
Electrical voltage Electrical voltage causes serious physical injury or death.
Raised load Falling objects can result in serious physical injury or death.
kg
Heavy load Heavy loads can result in serious back problems.
Risk of slipping Discharging pumped liquid and oils on the foundation or
tread surfaces can cause falls with serious physical injury
or death.
Flammable substances Discharging pumped liquid and oils can be easily inflam-
mable and can result in serious burns.
Hot surface Hot surfaces can cause burns.
1.3.3 Symbols in this document
Meaning
Warning personal injury
Safety instruction
Request for action
1.
2.
3.
Multi-step instructions for actions

Action result

Cross-reference
1.4 Associated documents
oCalibration certificate
oDeclaration of conformity according to EU Directive 2006/42/EC
oManufacturer's declaration according to EU Directive 2014/68/EU
oCorresponding operating instructions for accessories
Additional documents for ATEX version
oManufacturer's declaration according to EU Directive 2014/34/EU
oATEX supplementary instructions for usage in potentially explosive areas
Operating instructions OIO 30en-GB Edition 2019-04 5

2 Safety
2.1 Proper use
2 Safety
2.1 Proper use
oUse the flowmeter solely for measuring the flow of liquids that do not contain any gas components
or solid particles.
oIf coarse soiling, solid particles in the liquid or abrasive fine particles occur during operation, the
flowmeter has to be protected additionally by a correspondingly dimensioned operating filter in the
pipe system.
oUse the flowmeter only within the operating limits specified on the rating plate and in the chapter
"Technical data". Deviating operating data can result in damage to the flowmeter. In the case of op-
erating data that do not agree with the specifications on the rating plate, please contact the manu-
facturer.
oStrong changes in the flow rate (for example rapid shutdown, pulsations, etc.) cause marked pres-
sure differences in the flowmeter and can damage the measuring unit. The pressure loss of the
flowmeter must not exceed the values shown in the chapter "Technical data".
2.2 Foreseeable misuse
oAny use that extends beyond the proper use or any other use is misuse.
oThe product is not suitable for pumping liquids outside the operational limits.
oAny bypassing or deactivation of safety equipment during operation is prohibited.
2.3 Obligations of the operator-owner
The operator-owner is the person who operates the product commercially or permits a third party to
use it and who bears the legal responsibility for the product, the protection of the personnel and third
parties during its operation.
The product is used in industrial applications. The operator-owner is therefore subject to the statutory
obligations concerning occupational health and safety.
In addition to the safety instructions in these instructions, the regulations on safety, accident prevention
and environmental protection respectively valid for the range of application of the product are to be ob-
served.
This results in the following obligations for the operator-owner:
oObserve the rules and regulations such as national standards, international standards and provi-
sions applicable at the site of use.
oObserve the obligations arising from occupational safety and from safety, accident protection and
environmental protection.
oDraw up a hazard assessment for the utilization of the product at the site of use.
oDraw up the operating guidelines for the operation of the product on the basis of the hazard assess-
ment.
oKeep the operating guidelines up-to-date during the entire operating life of the product, by ensuring
that the current version of the applicable rules and regulations are integrated.
oEnsure the qualification, instruction, information on dangers as well as regular training of the per-
sonnel.
oSpecify clear responsibilities for all work on the product, for example for the installation, operation,
maintenance, troubleshooting.
oKeep the operating instructions available at the site of use - also for future use.
oEnsure that the operating instructions as well as the associated documents are read, understood
and observed by the personnel.
oObserve the safety regulations for handling dangerous pumped liquids and comply with the safety
data sheets. Pumped liquids can, for example, be hot, poisonous, combustible and caustic.
oMake personal protective equipment available and instruct their use.
oEquip systems with an increased potential of danger with protective equipment and/or alarm equip-
ment. The failure of a component may not result in injury and/or damage to property.
oMaintain and check protective equipment and alarm equipment regularly.
oEnsure the technically flawless state of the product during its entire operating life.
6OIO 30en-GB Edition 2019-04 Operating instructions

2 Safety
2.4 Dangers during transportation
2.4 Dangers during transportation
The following safety instructions must be observed:
oHave all work only carried out by authorized transport personnel.
oUse intact and correctly dimensioned hoisting equipment.
oEnsure that the means of transport is in a flawless state.
oEnsure that the centre of gravity of the load is taken into consideration.
oDo not stand under raised loads.
2.5 Dangers during storage
The following safety instructions must be observed:
oObserve the storage conditions.
2.6 Dangers during installation
The following safety instructions must be observed strictly:
oHave all work only carried out by authorized qualified personnel.
oDo not take apart the flowmeter.
oDo not remove the protective caps from the dry sleeves.
2.7 Dangers during removal
The following safety instructions must be observed strictly:
oHave all work only carried out by authorized qualified personnel.
oEnsure that the collection tank for emitted liquids is sufficiently large.
oCollect any discharging pumped liquid safely and dispose of it in an environmentally compatible
manner in accordance with the applicable local regulations.
oPlace the protective caps onto dry sleeves.
2.8 Dangers during connection work
The following safety instructions must be observed strictly:
oHave all the work on the flowmeter and pipe system only carried out by authorized qualified per-
sonnel.
oEnsure that solid particles cannot get into the flowmeter and pipe system.
oEnsure that mechanical connections are mounted free of stress.
oObserve the tightening torques.
oHave all the work on the electrical equipment only carried out by electricians.
oBefore beginning work on the flowmeter ensure that the electrical power supply is deenergized
and is secured against being switched back on.
oIf the insulation of the electrical cables or wires is damaged, disconnect the power supply immedi-
ately.
oThe connecting line of the pick up/temperature sensor connection is to be shielded and laid separ-
ately from the supply lines.
2.9 Dangers during operation
The following safety instructions must be observed strictly:
oHave all work only carried out by authorized qualified personnel.
oEnsure that the flowmeter is only operated within the operating limits.
oEnsure that during cooling down or heating up the flowmeter is only subjected to slow temperat-
ure changes.
oEnsure that existing safety equipment is not bypassed or activated during operation.
Operating instructions OIO 30en-GB Edition 2019-04 7

2 Safety
2.10 Dangers during servicing
2.10 Dangers during servicing
The following safety instructions must be observed strictly:
oHave all work only carried out by authorized qualified personnel.
oTo ensure the measuring precision, the measuring unit may only be replaced by the manufac-
turer.
oBefore beginning work, let the flowmeter cool down slowly to the ambient temperature. Avoid
rapid temperature changes.
oPumped liquids can be hot, poisonous, combustible and caustic.
oObserve the tightening torques Ä Appendix,Page45.
oObserve the operating instructions and data sheets of the sensors.
2.11 Dangers during disposal
The following safety instructions must be observed strictly:
oCollect any discharging pumped liquid safely and dispose of it in an environmentally compatible
manner in accordance with the applicable local regulations.
oEnsure that the collection tank for emitted liquids is sufficiently large.
oNeutralize residues.
8OIO 30en-GB Edition 2019-04 Operating instructions

3 Identification
3.1 Type code
3 Identification
3.1 Type code
OMS-020.CACABA.0001
1
2
3
4
5
68
7 9
Fig.1: Type code
1Series
2Size
3Sensor equipment (pick up)
4Function of the sensor equipment
5Material of bearing
6Material of seal
7Mechanical connection
8Electrical connection
9Version index
Item Designation Description
1Series OMS Stainless steel
2Size Corresponds to the diameter of the large measur-
ing screw in [mm]
3Sensor equipment (pick up) C BEG 44
F BEG 47
X Special design
4Function of the sensor equipment A Without recognition of flow direction
B With recognition of flow direction
C Without recognition of flow direction, with temper-
ature compensation
D With recognition of flow direction, with temperat-
ure compensation
X Special design
5Material of bearing C Stainless steel
X Special design
6 Material of seal A FPM (FKM)
B FFPM
C Low-temperature FPM
D EPDM
X Special design
7 Mechanical connection A Thread connection BSPP
B Flange connection DIN
C Thread connection NPT
D Flange connection ANSI
E Flange connection JIS
F Flange connection SAE
X Special design
8Electrical connection A Loose cable end
B Cable connection junction box
X Special design
9Version index For internal administration
Tab.2: Type code
Operating instructions OIO 30en-GB Edition 2019-04 9

4 Technical data
3.2 Rating plate
3.2 Rating plate
R
1 2 3
4567
Fig.2: Rating plate
1Serial number
2Construction year
3K-factor
4Preferred flow direction
5Max. temperature
6Series
7Max. pressure
4 Technical data
4.1 Operating limits
The values specified on the rating plate and the calibration certificate apply. The permissible operating
limits of individual values influence each other so that every application is checked individually by the
manufacturer when selecting the flowmeter.
If no operating data are provided by the orderer, standardized substitute operating data are used.
4.2 Pressure pulsation
p
[bar]
10 3020 40 t [ms]
30
10
20
0
p
[bar]
Fig.3: Pressure pulses
Strong pressure pulsations in the system can reduce the service life of the flowmeter.
4.3 Maximum values
The following table shows the respective maximum values that, however, may not occur simultan-
eously. In addition, the operating limits of the corresponding completion, of the sealing material and of
the pick up are to be observed.
Unit OMS-020 OMS-032 OMS-052
Flow rate
Qmax [l/min] 45 150 525
Qrated [l/min] 30 100 350
Qmin [l/min] 0.6 2.0 7.0
Max. pressure [bar] 185 185 120
Temperature
min - max [°C] -20 ... +150
Viscosity
min - max [mm2/s] 1–100
Measuring chamber volume [ml/U] 6.25 25.6 112.7
Rotation speed
N (Qmax) [min-1] 7200 5800 4658
N (Qrated) [min-1] 4800 3900 3105
N (Qmin) [min-1] 96 78 62
Tab.3: Maximum values
10 OIO 30en-GB Edition 2019-04 Operating instructions

4 Technical data
4.4 Substitute operating data
K2 Unit OMS-020 OMS-032 OMS-052
Pole number 8 12 16
K-factor [P/l] 1280 468 142
Millimetres/pulse [ml/P] 0.782 2.14 7.04
Pulse frequency
f2 (Qmax) [Hz] 960 1170 1243
f2 (Qrated) [Hz] 640 780 828
f2 (Qmin) [Hz] 12.8 15.6 16.6
Tab.4: Additional maximum values when BEG 44 is used
K1 Unit OMS-020 OMS-032 OMS-052
Pole number 468
K-factor [P/l] 640 234 71
Millimetres/pulse [ml/P] 1.56 4.27 14.08
Pulse frequency
f1 (Qmax) [Hz] 480 585 621
f1 (Qrated) [Hz] 320 390 414
f1 (Qmin) [Hz] 6.4 7.8 8.2
Tab.5: Additional maximum values when BEG 47D is used
4.4 Substitute operating data
The following table shows standardized values for the flow rate, temperature and viscosity. These val-
ues can be used at the same time as maximum values without impairing the service life of the flow-
meter. In addition, the operating limits of the corresponding completion, of the sealing material of the
pick up and of the temperature sensor are to be observed.
Unit OMS-020 OMS-032 OMS-052
Flow rate
Qmax [l/min] 30 100 350
Qrated [l/min] 30 100 350
Qmin [l/min] 0.6 2.0 7.0
Max. pressure [bar] 250 250 160
Temperature
min - max [°C] -20 ... +120
Viscosity
min - max [mm2/s] 1–100
Tab.6: Substitute operating data
4.5 Sound pressure level
The sound pressure level of the flowmeters amounts to less than 70 dB(A).
Operating instructions OIO 30en-GB Edition 2019-04 11

4 Technical data
4.6 Dimensions and weights
4.6 Dimensions and weights
4.6.1 Pipe thread (BSPP thread)
L1
L2
D
G
M18x1
G1/4"
T T
Fig.4: Dimensional drawing pipe thread
GPipe thread
M18x1 Pick up hole
G1/4" Temperature sensor hole
DOuter diameter
L1 Total length
L2 Length of the flowmeter without
connections
TMax. screw-in depth
Unit OMS-020 OMS-032 OMS-052
G [inch] 3/4 1 1 1/2
Pressure stage [bar] 185 185 120
D [mm] 74 104 118
L1 [mm] 145 215 295
L2 [mm] 145 215 240
T [mm] 16.0 18.0 27.5
Weight [kg] 4.1 11.0 18.0
Tab.7: Dimensions and weights - pipe thread connection
4.6.2 DIN flange
L3
D
TK
G1/4"
DN
M18x1
L3 L2
L1
Fig.5: Dimensional drawing DIN flange
DN Nominal diameter flange
M18x1 Pick up hole
G1/4" Temperature sensor hole
DOuter diameter
L1 Total length
L2 Length of the flowmeter without
connections
L3 Flange thickness
TK Pitch circle
Unit OMS-020 OMS-032 OMS-052
DN 20 32 25 40
Pressure stage [bar] 40 40 160 40
D [mm] 105 140 140 150
L1 [mm] 185 265 265 285
L2 [mm] 145 215 215 240
L3 [mm] 20.5 25.0 25.0 22.5
TK [mm] 75 100 100 110
Weight [kg] 6.0 16.0 16.0 21.0
Tab.8: Dimensions and weights – DIN flange connection
12 OIO 30en-GB Edition 2019-04 Operating instructions

4 Technical data
4.7 Pressure bearing capacity
4.7 Pressure bearing capacity
4.7.1 Pressure bearing capacity OMS-020
20
18
16
14
12
2
4
6
8
10
0
A
B
1000 h
30000 h
10000 h
5000 h
100000
5
10
50
200
500
1000
2000
5000
10000
50000
100
[mm2/s]
C
[bar]
[bar]
C
2
3
0
1
100000
5000
10000
50000
5
10
50
200
500
1000
2000
100
[mm2/s]
69 12 3027
24
21
1815
0,3 345
42
39
36
33
E
D
[l/min]
100 50 150
D
[l/min]
50
45
40
30
25
20
1510
51 35
10,5 7,5
4,51,5
0,3 13,5 15
3 6 9 12
[%] [%]
1
AShort-term operation
BContinuous operation
CPressure loss
DFlow rate
EQrated
The values apply for lubricating liquids at temperatures up to 120°C. Abrasive and aggressive liquids
reduce the service life.
Operating instructions OIO 30en-GB Edition 2019-04 13

4 Technical data
4.7 Pressure bearing capacity
4.7.2 Pressure bearing capacity OMS-032
20
18
16
14
12
2
4
6
8
10
0
A
B
1000 h
30000 h
10000 h
5000 h
100000
5
10
50
200
500
1000
2000
5000
10000
50000
100
[mm2/s]
C
[bar]
[bar]
C
2
3
0
1
100000
5000
10000
50000
5
10
50
200
500
1000
2000
100
[mm2/s]
20 30 40 10090
80
70
6050
110 150
140
130
120
110
E
D
[l/min]
100 50 150
D
[l/min]
50
45
40
30
25
20
1510
51 35
35 25
155
1 45 50
10 20 30 40
[%] [%]
1
AShort-term operation
BContinuous operation
CPressure loss
DFlow rate
EQrated
The values apply for lubricating liquids at temperatures up to 120°C. Abrasive and aggressive liquids
reduce the service life.
14 OIO 30en-GB Edition 2019-04 Operating instructions

4 Technical data
4.7 Pressure bearing capacity
4.7.3 Pressure bearing capacity OMS-052
20
18
16
14
12
2
4
6
8
10
0
A
B
1000 h
30000 h
10000 h
5000 h
100000
5
10
50
200
500
1000
2000
5000
10000
50000
100
[mm2/s]
C
[bar]
[bar]
C2
3
0
1
100000
5000
10000
50000
5
10
50
200
500
1000
2000
100
[mm2/s]
70 105 140 350315
280
245
210175
3,5 35 525
490
455
420
385
E
D
[l/min]
100 50 150
D
[l/min]
50
45
40
30
25
20
1510
51 35
122,5 87,5
52,517,5
3,5 157,5 175
35 70 105 140
[%] [%]
1
AShort-term operation
BContinuous operation
CPressure loss
DFlow rate
EQrated
The values apply for lubricating liquids at temperatures up to 120°C. Abrasive and aggressive liquids
reduce the service life.
Operating instructions OIO 30en-GB Edition 2019-04 15

5 Function description
5.1 Structure
5 Function description
5.1 Structure
12/2a 345 2 3 1
6
78
9
10
Fig.6: Structure of the flowmeter
1Connection 6Ball bearing floating bearing end
2Screw plug 7Measuring screw large
2a Connection of temperature sensor 8Ball bearing fixed bearing end
3Bearing cover 9Pick up hole
4Measuring housing 10 Pole wheel
5Measuring screw small
5.2 Functional principle
Flowmeters belong to the group of rotating displacement meters as screw meters. The pumped liquid
makes the measuring unit rotate. The displacement effect results from the continuous filling, axial dis-
placement and discharge of the volumes that are formed by the measuring housing and measuring
unit. The measured pumped liquid flows around and lubricates all the rotating parts. Thanks to the dis-
placement principle, the flowmeter does not require inlet sections and smoothing sections at the feed
line and outlet.
Depending on the customer requirements, the flowmeters can be equipped with suitable end connec-
tions for connection to various flanges.
5.3 Rolling bearings
Thanks to precision rolling bearings the measuring unit operates contact-free and with low friction in
the housing of the flowmeter.
The bearing on the side of the pole wheel is realized with a single-row deep-groove ball bearing as a
fixed bearing. The bearing on the opposite side of the measuring unit is realized with a displaceable
deep-groove ball bearing as a floating bearing.
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5 Function description
5.4 Signal generation
5.4 Signal generation
A pole wheel10 whose pole is sampled by a pick up is affixed at the end of the large measuring
screw7. This pick up generates a specific number of pulses per flow volume unit - depending on the
size and working point. This device-specific characteristic is called the K-factor (unit: Pulse/litre) and is
specified on the rating plate as well as the enclosed calibration certificate.
Possible formats of the signals are:
oPNP
oNAMUR
Depending on the version of the pick up, cylindrical pole wheels with embedded magnets or toothed
metal disks with different tooth densities can be used (higher pole number = higher K-factor).
The mounting method of the pick-up allows mounting without contact with the liquid to be measured.
Two different pick ups are employed, depending on the application (standard, or for use in areas where
there is an explosion hazard):
oPick ups based on the Hall effect
oInductive pick up
The preferred flow direction is specified on the rating plate of the flowmeter. When this flow direction is
observed, the pick up is located on the low-pressure end (outlet) in the case of blocking.
5.5 Linearization
The calibration certificate of the flowmeter contains a mean K-factor that has been determined for the
flow range 10:1 and that can therefore be used across a wide flow range. However, the K-factor shows
slightly different values at different flow rates. These are also documented in the enclosed calibration
certificate. If highest measuring precision is required, it is therefore advisable, especially at strongly
varying flow rates, to take these different values into consideration by means of a "Linearization". The
K-factors are therefore stored in a suitable electronic unit by means of several interpolation values of
the flow rate. The K-factor relevant for the flow rate being measured is then determined by means of
linear interpolation between the two nearest interpolation values.
The viscosity dependence of the K-factors must also be taken into account. These are determined dur-
ing calibration at a viscosity of approximately 4.2 mm²/s. The influence of the flow rate on the K-factor
decreases at higher viscosities so that the mean K-factor can then also be used in a considerably lar-
ger flow range without noteworthy errors.
5.6 Temperature compensation
Flowmeters of the series OMS can additionally be equipped with a temperature sensor. The current
density of the flowing liquid can be calculated from the measured values of the temperature sensor by
using a density table stored in the electronic unit. This allows standardised volume measurement in
which the displayed values are converted to a reference temperature that can be selected freely. This
ensures that measuring errors caused by changes in the density due to temperature variations are
avoided.
5.7 Recognition of flow direction
Systems with a changing flow direction require the usage of a second pick up to recognize the change
in direction. In the case of systems with pressure pulsation a reversal of the flow direction can also oc-
cur briefly.
The flow direction can be determined by means of the additional phase-shifted signal and the incre-
mental encoder positions available in the KRALelectronic unit and then taken into account for the cal-
culation of the total values.
Operating instructions OIO 30en-GB Edition 2019-04 17

6 Transportation, storage
6.1 Dangers during transportation
6 Transportation, storage
6.1 Dangers during transportation
The following safety instructions must be observed:
oHave all work only carried out by authorized transport personnel.
oUse intact and correctly dimensioned hoisting equipment.
oEnsure that the means of transport is in a flawless state.
oEnsure that the centre of gravity of the load is taken into consideration.
oDo not stand under raised loads.
6.2 Dangers during storage
The following safety instructions must be observed:
oObserve the storage conditions.
6.3 Unpacking and checking the state of delivery
1. Upon delivery unpack the flowmeter and check it for damage during transportation.
2. Report damage during transportation immediately to the manufacturer.
3. Store the supplied sensors for the installation.
4. Dispose of packaging material in accordance with the locally applicable regulations.
6.4 Transporting flowmeters
WARNING
Risk of injury and damage to equipment through falling and toppling parts.
► Use intact and correctly dimensioned hoisting equipment in accordance with the total weight to be
transported.
► Select the lift points for the hoisting equipment in accordance with the centre of gravity and the
weight distribution.
► Use at least two load ropes.
► Do not stand under raised loads.
ATTENTION
Damage to equipment through improper transportation.
► Protect the flowmeter against damage, heat, sunlight, dust and moisture.
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6 Transportation, storage
6.5 Storing the flowmeter
Requirement:
üSufficiently dimensioned hoisting equipment
üThe used hoisting equipment corresponding to the local rules and regulations for the prevention of
accidents
Fig.7: Fastening of hoisting equipment - principle diagram
Fasten hoisting equipment on the flowmeter.
6.5 Storing the flowmeter
As a result of the calibration, the internal components of the flowmeter are wetted with calibration liquid
that has a preservative effect. In addition, a special anticorrosive agent is sprayed onto the interior of
the flowmeter before being dispatched. The connections of the flowmeter are fitted with protective cov-
ers. The preservation applied at the factory will protect the flowmeter for up to six weeks, if it is stored
in a dry and clean location. The manufacturer optionally offers a long-term preservation for storage
times of up to 60 months. The flowmeter is additionally packed in hermetically sealing anti-corrosion
paper.
ATTENTION
Damage to equipment and corrosion if stored improperly and during longer standstills.
► Protect the flowmeter against damage, heat, sunlight, dust and moisture.
► Protect against corrosion during longer standstill.
► Observe measures for storing and preservation.
1. Store cool and dry and protect against sunlight.
2. Observe the information on preservation.
6.6 Preservation
6.6.1 Preservation table
Preservation has to be carried out additionally under the following conditions:
Type of delivery Condition
Standard delivery oStorage time exceeding six weeks
oUnfavourable storage conditions such as high humidity,
salty air, etc.
Delivery with long-term preservation oOpened or damaged packaging
Tab.9: Conditions for additional preservation
Notice After a longer storage time the manufacturer recommends that you have the flowmeter recalibrated Ä
Maintenance,Page29.
Operating instructions OIO 30en-GB Edition 2019-04 19

6 Transportation, storage
6.6 Preservation
6.6.2 Preserving the inner surfaces
Personnel qualification: oTrained personnel
Personal protective equipment: oWork clothing
oProtective gloves
oSafety boots
1. Close a connection of the flowmeter with a blind flange.
2. Position the flowmeter vertically.
3. Fill non-corrosive and resin-free oil into the pressure connection up to approx. 1cm under the
flange at the top, while turning the measuring unit slowly, so that the measuring unit is also wet-
ted.
4. Close the upper connection with a blind flange.
5. After about six months storage check the filling level of the oil and if necessary top up.
6.6.3 Preserving the outer surfaces
Personnel qualification: oTrained personnel
Personal protective equipment: oWork clothing
oProtective gloves
oSafety boots
1. Paint or spray the preservative onto all plain and unpainted parts.
2. At intervals of about six months check the preservation and if necessary repeat.
6.6.4 Removing the preservation
Personnel qualification: oTrained personnel
Personal protective equipment: oWork clothing
oProtective gloves
oSafety boots
Aids: oSolvent
oCollection tank
CAUTION
Risk of injury through emitted preservative.
► Wear personal protective clothing during all the work.
► Collect any discharging preservative safely and dispose of it in an environmentally compatible
manner in accordance with the applicable local regulations.
1. Remove one of the blind flanges.
2. Drain the flowmeter, collecting the preservative oil in a suitable vessel.
3. Remove the second blind flange.
4. Either remove the residual oil with solvent or flush the flowmeter with pumped liquid.
20 OIO 30en-GB Edition 2019-04 Operating instructions