KROHNE DK32 Series Wiring diagram

Variable area flowmeter with electrical built-ins
Equipment category II 2 G / II 2 D, EPL Gb / Db
in protection type intrinsic safety "i"
DK32 - DK34
DK32 - DK34DK32 - DK34
DK32 - DK34 Supplementary Instructions
Supplementary InstructionsSupplementary Instructions
Supplementary Instructions
© KROHNE 12/2019 - 4007138001 - AD DK32-34 Exi Gb-Db R01 en

CONTENTS
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DK32 - DK34
1 Safety instructions 3
1.1 General notes ................................................................................................................... 3
1.2 EU conformity ................................................................................................................... 3
1.3 Approval according to the IECEx scheme ........................................................................ 3
1.4 Safety instructions............................................................................................................ 4
2 Device description 5
2.1 Device description ............................................................................................................ 5
2.2 Description code............................................................................................................... 5
2.3 Marking............................................................................................................................. 6
2.4 Flammable products ........................................................................................................ 8
2.5 Equipment category .........................................................................................................8
2.6 Types of protection ........................................................................................................... 9
2.7 Ambient temperature / temperature classes................................................................ 10
2.8 Surface temperature for equipment category II 2 D...................................................... 13
2.9 Electrical data................................................................................................................. 13
3 Installation 14
3.1 Mounting ......................................................................................................................... 14
4 Electrical connections 15
4.1 General notes ................................................................................................................. 15
4.2 Grounding and equipotential bonding............................................................................ 17
5 Operation 18
5.1 Start-up........................................................................................................................... 18
5.2 Operation ........................................................................................................................ 18
5.3 Electrostatic charge .......................................................................................................18
6 Service 19
6.1 Maintenance ................................................................................................................... 19
6.2 Dismantling .................................................................................................................... 20
7 Notes 21

SAFETY INSTRUCTIONS 1
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1.1 General notes
This additional instruction applies to explosion-protected versions of variable area flowmeters
with electrical built-ins and the marking II 2 G and II 2 D or EPL Gb and Db.
It completes the standard manual for the non explosion-protected versions.
The information given in this instruction contains only the data relevant to explosion protection
of category 2.
The technical details given in the manual for the non explosion-protected versions remain
unchanged unless they will be excluded or replaced by this supplementary instruction.
1.2 EU conformity
The manufacturer declares with the EU declaration of conformity on his own responsibility
conformity with the protection goals of directive 2014/34/EU for use in hazardous areas.
Conformity with harmonised standards was checked in accordance with EN 60079-0:2012 and
EN 60079-11:2012.
The EU declaration of conformity is based on the EU type examination certificate of the KIWA
ExVision:
If necessary, the EU type examination certificate can be downloaded from the manufacturer's
website.
1.3 Approval according to the IECEx scheme
Conformity with IECEx standards was tested in accordance with the "IECEx Certification Scheme
for Explosive Atmospheres" according to IEC 60079-0:2011 and IEC 60079-11:2011.
The number of the IEC certificate is:
KIWA 18ATEX0008 X
KIWA 18ATEX0008 XKIWA 18ATEX0008 X
KIWA 18ATEX0008 X
IECEx KIWA 18.0007X
IECEx KIWA 18.0007XIECEx KIWA 18.0007X
IECEx KIWA 18.0007X

1 SAFETY INSTRUCTIONS
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1.4 Safety instructions
If these instructions are not followed, there is a risk of explosion.
Assembly, installation, start-up and maintenance may only be performed by personnel trained in
explosion protection!
CAUTION!
The operator or his agent is responsible for observing any additional standards, directives or
laws if required due to operating conditions or place of installation.
This applies in particular to the use of easily detachable process connections when measuring
flammable media.
CAUTION!
When an equipment fault is detected the device shall be de-energised and send back to the
manufacturer for repair.

DEVICE DESCRIPTION 2
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2.1 Device description
Variable area flowmeters measure and display the flow of flammable and non-flammable gases
and liquids. Depending on the device version, one or two individually adjustable electrical limit
switch contacts can be installed in the indication unit.
The indication unit can also be equipped with a Reed contact or a 4...20 mA signal output with
HART
®
communication.
2.2 Description code
The safety description code consists of the following elements *:
* positions which are not needed are omitted (no blank positions)
Figure 2-1: Safety description code
1 32 - with valve and horizontal connection / 34 - without valve and vertical connection
2 RE - inlet pressure regulator / RA - outlet pressure regulator
3 K1 - one limit switch / K2 - two limit switches /
ESK - version with current output / R1 - version with Reed contact
4 S - plug connector / L - cable entry including cable
5 HT - high-temperature version
6 Marking without influence on the explosion safety protection
7 Ex - explosion-protected equipment
8 SK - SIL conformity according to IEC 61508 of the limit switch

2 DEVICE DESCRIPTION
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2.3 Marking
The marking of the entire device is on the indication unit, where the following identification plate
can be found. An additional marking with the production number (P/A) is located inside of the
indication.
Figure 2-2: Example of a nameplate with limit switches
1 Device type
2 Manufacturer
3 Notified body ATEX
4 Rating data: temperature & pressure rating
5 Ex data according to KIWA 18ATEX0008 X or IECEx KIWA 18.0007X
6 Built-in equipment
7 Note to observe the documentation and for disposal
8 PED data

DEVICE DESCRIPTION 2
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Figure 2-3: Example of a nameplate with current output
1 Device type
2 Manufacturer
3 Notified body ATEX
4 Rating data: temperature & pressure rating
5 Ex data according to KIWA 18ATEX0008 X or IECEx KIWA 18.0007X
6 Built-in equipment
7 Note to observe the documentation and for disposal
8 PED data
Figure 2-4: Example of a nameplate with Reed contact
1 Device type
2 Manufacturer
3 Notified body ATEX
4 Rating data: temperature & pressure rating
5 Ex data according to KIWA 18ATEX0008 X or IECEx KIWA 18.0007X
6 Built-in equipment
7 Note to observe the documentation and for disposal
8 PED data

2 DEVICE DESCRIPTION
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2.4 Flammable products
Atmospheric conditions:
Atmospheric conditions:Atmospheric conditions:
Atmospheric conditions:
The standard atmospheric conditions under which it may be assumed that Ex equipment can be
operated are:
•Temperature: -20...+60°C / -4...+140°F
•Pressure: 80...110 kPa (0.8...1.1 bar) / 11.6...15.9 psi
•Air with normal oxygen content, typically 21%v/v
Ex equipment operating outside the standard temperature range must be tested and certified
(e.g. for ambient temperature range -40...+65°C / -40...+149°F).
Ex equipment operating outside the standard atmospheric pressure range and standard oxygen
content is not permitted.
Operating conditions:
Operating conditions:Operating conditions:
Operating conditions:
The measuring unit of variable area flowmeters operate outside the standard atmospheric
pressure range, which means that explosion protection, regardless of the zone assignment, is
fundamentally not applicable for the measuring unit (piping).
2.5 Equipment category
Variable area flowmeters are designed according to EN 60079-0 and EN 60079-11 in
category II 2 G or EPL Gb for use in zone 1.
Depending on the device version, variable area flowmeters are also designed in
category II 2 D or EPL Db for use in zone 21.
The inside of the measuring unit is also approved for zone 1.
CAUTION!
Operation with flammable products is only permitted as long as no explosive fuel/air mixture
builds up inside of the piping at the same time the atmospheric conditions are exceeded.
The operator is responsible to ensure that the flowmeter is operated safely in terms of the
temperature and pressure of the products used. In case of operation with flammable products
the measuring units must be included in the periodic pressure tests of the piping.
INFORMATION!
Definition of zone 1:
An area in which an explosive atmosphere, as a result of the mixture of flammable substances in
the form of gas, steam or mist with air, under normal operation may occasionally occur.
Definition of zone 21:
An area in which an explosive atmosphere may occasionally occur in the form of a cloud of
flammable dust in the air under normal operation.

DEVICE DESCRIPTION 2
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2.6 Types of protection
The variable area flowmeter is designed with protection type intrinsic safety "i" according to
EN 60079-11.
The identification for equipment category II 2 G or EPL Gb is:
II 2G Ex ia IIC T6...T1 Gb or Ex ia IIC T6...T1 Gb
II 2G Ex ia IIC T6...T1 Gb or Ex ia IIC T6...T1 GbII 2G Ex ia IIC T6...T1 Gb or Ex ia IIC T6...T1 Gb
II 2G Ex ia IIC T6...T1 Gb or Ex ia IIC T6...T1 Gb
The marking contains the following information:
The additional identification of the version for the equipment category II 2 D and EPL Db is:
II 2D Ex ia IIIC T85
II 2D Ex ia IIIC T85II 2D Ex ia IIIC T85
II 2D Ex ia IIIC T85°C...T140
C...T140C...T140
C...T140°C Db or Ex ia IIIC T85
C Db or Ex ia IIIC T85C Db or Ex ia IIIC T85
C Db or Ex ia IIIC T85°C...T140
C...T140C...T140
C...T140°C Db
C DbC Db
C Db
The marking contains the following information:
II
IIII
II Explosion protection, group II
2
22
2Equipment category 2
G
GG
GGas explosion protection
Ex ia
Ex iaEx ia
Ex ia Explosion protection through intrinsic safety, protection level "ia"
IIC
IICIIC
IIC Gas group, suitable for gas groups IIC, IIB and IIA
T6...T1
T6...T1T6...T1
T6...T1 Temperature class range, suitable for temperature classes T6...T1
Gb
GbGb
Gb EPL, suitable for zone 1
Table 2-1: Description of the marking
INFORMATION!
For the equipment category II 2 G or EPL Gb, connection to an intrinsically safe circuit with
protection level "ib" is required.
When connecting the variable area flowmeter to an intrinsically safe circuit with protection level
"ia", a higher protection level is given.
II
IIII
II Explosion protection, group II
2
22
2Equipment category 2
D
DD
DDust ignition protection
Ex ia
Ex iaEx ia
Ex ia Explosion protection through intrinsic safety, protection level "ia"
IIIC
IIICIIIC
IIIC Dust group, suitable for groups IIIC, IIIB and IIIA
T85
T85T85
T85°C...T140
C...T140C...T140
C...T140°C
CC
CMaximum surface temperature at +65°C / +149°F ambient temperature
Db
DbDb
Db EPL, suitable for zone 21
Table 2-2: Description of the marking
INFORMATION!
For the equipment category II 2 D or EPL Db, connection to an intrinsically safe circuit with
protection level "ib" is required.
When connecting the variable area flowmeter to an intrinsically safe circuit with protection level
"ia", a higher protection level is given.

2 DEVICE DESCRIPTION
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2.7 Ambient temperature / temperature classes
Due to the influence of the product temperature, no fixed temperature class is assigned to
variable area flowmeters. The temperature class of these devices is rather a function of the
present product temperature and ambient temperature. There is no distinction between devices
with one or two contacts.
The classification is outlined in the following tables.
The tables take into account the following parameters:
•Ambient temperature T
amb
•Product temperature T
m
•Feed power for version K. depending on the limit switches
INFORMATION!
The lowest ambient temperature for the version with limit switch of the type SC2-NO or Reed
contact HT is -25
° C/-13 ° F, for all other versions it is -40 ° C/-40 ° F.
INFORMATION!
The maximum permissible product temperatures listed in the tables are valid under
the following conditions:
• The measuring device is installed and operated in accordance with the installation
instructions in the standard manual.
• It must be ensured that the flowmeter is not heated by the effects of additional heat radiation
(sunshine, neighbouring system components) and thus operated above the permissible
ambient temperature range.
• Insulation must be limited to the piping.
Unobstructed ventilation of the indicator part must be ensured.
Maximum permissible product temperature T
m
[°C]
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 40 50 55 50 65 70 40 60 65 70 40 60 65 70
DK3./../ESK/. 85 85 85 100 100
190 1135 1105 1100 190 1140 1105 1100 190 1
Table 2-3: DK3./../ESK/./..-Ex permissible product and ambient temperatures in °C
1Heat-resistant cable and cable entry ≥90°C
Maximum permissible product temperature T
m
[°F]
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 104 122 131 122 149 158 104 140 149 158 104 140 149 158
DK3./../ESK/. 185 185 185 212 212
1194 1275 1221 1212 1194 1284 1221 1212 1194 1
Table 2-4: DK3./../ESK/./..-Ex permissible product and ambient temperatures in °F
1Heat-resistant cable and cable entry ≥194°F

DEVICE DESCRIPTION 2
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Limit switches
Feed power
Maximum permissible product temperature T
m
[°C] with plug connector (S) or cable
entry (L)
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 40 50 55 40 50 55 40 60 65 70 90 40 60 65 70 90
SC2-NO 64 mW 80 70 65 100 100 95 135 125 120
1120 1100 1140 1125 1120 1120 1100 1
SC2-NO 169 mW ---55 - - 90 75 70 - - 90 75 70 - -
SJ2-SN 64 mW 80 70 70 100 100 95 135 125 120
1120 1100 1140 1125 1120 1120 1100 1
SJ2-SN 169 mW ---60 55 -95 80 75
170 1-95 80 75 170 1-
I7S2002-N 64 mW 85 80 75 100 100 100 135 125 120
1120 1100 1140 1125 1120 1120 1100 1
I7S2002-N 169 mW 55 - - 80 70 70 135 120 115
1110 195 1135 1120 1115 1110 195 1
Table 2-5: DK3./../K././..-Ex permissible product and ambient temperatures in °C
1Heat-resistant cable and cable entry ≥90°C
Limit switches
Feed power
Maximum permissible product temperature T
m
[°F] with plug connector (S) or cable
entry (L)
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 104 122 131 104 122 131 104 140 149 158 194 104 140 149 158 194
SC2-NO 64 mW 176 158 149 212 212 203 275 257 248
1248 1212 1284 1257 1248 1248 1212 1
SC2-NO 169 mW ---131 - - 194 167 158 - - 194 167 158 - -
SJ2-SN 64 mW 176 158 158 212 212 203 275 257 248
1248 1212 1284 1257 1248 1248 1212 1
SJ2-SN 169 mW ---140 131 -203 176 167
1158 1-203 176 167 1158 1-
I7S2002-N 64 mW 185 176 167 212 212 212 275 257 248
1248 1212 1284 1257 1248 1248 1212 1
I7S2002-N 169 mW 131 - - 176 158 158 275 248 239
1230 1203 1275 1248 1239 1230 1203 1
Table 2-6: DK3./../K././..-Ex permissible product and ambient temperatures in °F
1Heat-resistant cable and cable entry ≥194°F

2 DEVICE DESCRIPTION
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DK3x indicator
with Reed contact
Maximum permissible product temperature T
m
[°C] with plug connector (S) or cable
entry (L)
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 55 70 70 100
DK3./../R1/... 85 100 1135 1150 1
Table 2-7: DK3./../R1/./..-Ex permissible product and ambient temperatures in °C
1Heat-resistant cable and cable entry ≥90°C
DK3x indicator
with Reed contact
Maximum permissible product temperature T
m
[°F] with plug connector (S) or cable
entry (L)
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 131 158 158 212
DK3./../R1/... 185 212 1275 1302 1
Table 2-8: DK3./../R1/./..-Ex permissible product and ambient temperatures in °F
1Heat-resistant cable and cable entry ≥194°F
DK3x high-
temperature
indicator with
Reed contact
Maximum permissible product temperature T
m
[°C]
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 55 85 90 145 180
DK3./../R1/L/HT 85 100 135 200 180
Table 2-9: DK3./../R1/L/HT/..-Ex permissible product and ambient temperatures in °C
DK3x high-
temperature
indicator with
Reed contact
Maximum permissible product temperature T
m
[°F]
T6
T6T6
T6 T5
T5T5
T5 T4
T4T4
T4 T3...T1
T3...T1T3...T1
T3...T1
Ambient
temperature 131 185 194 293 356
DK3./../R1/L/HT 185 212 275 392 356
Table 2-10: DK3./../R1/L/HT/..-Ex permissible product and ambient temperatures in °F
WARNING!
Also, when operating the variable area flowmeter outside of the hazardous area, the connection
must be made to intrinsically safe circuits.
When connecting to non-intrinsically safe circuits, there is a risk of damage to the safety-
defining components.

DEVICE DESCRIPTION 2
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2.8 Surface temperature for equipment category II 2 D
For use in areas with combustible dust it should be noted that the indicated maximum surface
temperature of T85°C at an ambient temperature of +65°C / +149°F and a product temperature
of +75°C / +167°F is valid without a dust layer.
For higher product temperatures the maximum surface temperature is defined by the product.
At temperatures above +90°C / +194°F, heat-resistant cables and cable entries ≥+90°C / +194°F
must be used.
2.9 Electrical data
The electrical signal circuits may only be connected to separate, intrinsically safe circuits.
Depending on the instrument design, the following maximum values apply per circuit:
Irrespective of the device version the following values are to be observed for each intrinsically
safe circuit in case of interconnection:
U
i
16 VDC
I
i
25 mA or 52 mA
P
i
64 mW or 169 mW
Table 2-11: Version DK3./../K././..-Ex
C
i
150 nF
L
i
150 µH
Table 2-12: Up to a cable length of 10 m / 32.8 ft
C
i
152 nF
L
i
150 µH
Table 2-13: Starting with a cable length of more than 10 m / 32.8 ft up to 20 m / 65.6 ft
Version DK3./../ESK/./..-Ex Version DK3./../R1/./..-Ex
U
i
30 VDC 30 VDC
I
i
130 mA 100 mA
P
i
1W 1W
C
i
10 nF ≈0nF
L
i
≈0 µH≈0 µH
Table 2-14: Version DK3./../ESK/./..-Ex or version DK3./../R1/./..-Ex

3 INSTALLATION
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3.1 Mounting
Mounting and setup must be carried out according to the applicable installation standards
(e.g. IEC 60079-14) by qualified personnel trained in explosion protection.
The information given in the manual and the supplementary instructions must always be
observed.
Variable area flowmeters must be installed in such a way that
•there is no danger from mechanical impact effects.
•There are no external forces affecting the indicator part.
•the device is accessible for any necessary visual inspections and can be viewed from all sides.
•the nameplate is clearly visible.
•it can be operated from a location with secure footing.
CAUTION!
The manufacturer is not liable for any damage resulting from improper use or use other than the
intended purpose. This applies in particular to hazards due to insufficient corrosion resistance
and suitability of the materials in contact with product.
DANGER!
Components made of titanium in oxygen applications
Components made of titanium in oxygen applicationsComponents made of titanium in oxygen applications
Components made of titanium in oxygen applications
Variable area flowmeters with titanium components are NOT
NOTNOT
NOT suitable for use in explosion-
protected areas in conjunction with oxygen applications (products with an oxygen content which
is significantly above the oxygen content in the earth's atmosphere)!

ELECTRICAL CONNECTIONS 4
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4.1 General notes
For version DK3./../ESK/../..-Ex (current output), the signal circuits are electrically connected in
the terminal compartment of the current output, for version DK3./../../S/..-Ex (plug) in the
terminal compartment of the plug housing and for version DK3./../../L/..-Ex (connecting cable) it
is the connecting cable as illustrated in the connection diagram.
Permissible maximum values (electrical data) must be observed.
Current output
The DK3./../ESK/../..-Ex variable area flowmeter is equipped with a current output. The current
output is delivered with a suitable cable entry.
The cable entry guarantees protection against foreign objects and water (ingress protection)
IP6x according to EN 60529 in combination with a suitable connecting cable.
The connecting cable must be selected according to prevailing installation standards
(e.g. EN 60079-14). The outer diameter of the connecting cables must be within the sealing
range of the cable entry. The connecting cable must be fixed and laid so they are sufficiently
protected against damage.
Connecting cable
The DK3./../../S/..-Ex variable area flowmeter is equipped with a pre-assembled connecting
cable.
The connecting cable must be selected according to prevailing installation standards
(e.g. EN 60079-14). The outer diameter of the connecting cables must be within the sealing
range of the cable entry. The connecting cable must be fixed and laid so they are sufficiently
protected against damage.
All cores that are not used must be securely connected to the ground potential of the hazardous
area or carefully insulated against each other and against ground (test voltage ≥500 V
eff
).
Cable entries / blanking plugs
The DK3./../../S/..-Ex variable area flowmeter is equipped with a connector. The connector
guarantees protection against foreign objects and water (ingress protection) IP65 according to
EN 60529. The cable entry is closed with a plug. The plug is to be replaced with a suitable
connecting cable (nominal diameter range 6...9 mm).
The connecting cable must be selected according to prevailing installation standards
(e.g. EN 60079-14). The outer diameter of the connecting cable must be within the sealing range
of the cable entry. The connecting cable must be fixed and laid so they are sufficiently protected
against damage.

4 ELECTRICAL CONNECTIONS
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Connection for indicator with limit switches or Reed contact
Connection for indicator with current output ESK
Figure 4-1: Connection for indicator with limit switches or Reed contact
Contact connection Stranded wire colour for cable assembly
1Min minus white
2Min plus yellow
3Max minus green
4Max plus brown
5Lift slot
6Fastening screw of connection box
Table 4-1: Stranded wire colour for cable assembly
Figure 4-2: Electrical connection ESK
1 Connection terminals
2 Cable entry

ELECTRICAL CONNECTIONS 4
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4.2 Grounding and equipotential bonding
If the device is not sufficiently electrostatically grounded via the process pipes, an additional
ground connection must be established using the ground terminal 1
11
1. The position of the ground
terminal is illustrated below. The connection only ensures an electrostatic connection of the
device and does not comply with the requirements of an equipotential bonding connection.
For the version with current output, this can also be done at the ground terminal of the housing.
The position of the ground terminal is illustrated below.
Figure 4-3: Ground terminal for DK32, DK34
Figure 4-4: Ground terminal for ESK
INFORMATION!
The temperature at the electrostatic equalization connector on the DK32-DK34 measuring unit
corresponds to the process temperature. It is thus the responsibility of the operator to select the
connecting cable according to the process temperature.

5 OPERATION
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5.1 Start-up
Start-up is only permitted when the variable area flowmeter:
•is correctly installed in the system and connected.
•has been checked for the proper state with regard to its installation and connection
requirements.
The operator of the system has to check prior to start-up, if the start-up was in compliance with
the national regulations for checks.
5.2 Operation
For the device version with limit switches, adjusting during operation is permitted. To do so,
remove the housing cover. Close the housing cover immediately after adjusting the limit switch.
5.3 Electrostatic charge
In order to avoid ignition hazards due to electrostatic charge, variable area flowmeters
may not be used in areas with:
•processes that generate strong charges,
•mechanical friction and cutting processes,
•spraying of electrons (e.g. in the vicinity of electrostatic painting systems).
CAUTION!
Ignition risks caused by pressure surges, impact or friction must particularly be avoided when
titanium measuring units or floats are used.
WARNING!
Electrostatic charging of the housing surface by friction must be avoided.
Variable area flowmeters must not be dry cleaned.

SERVICE 6
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6.1 Maintenance
Maintenance work of a safety-relevant nature within the meaning of explosion protection may
only be carried out by the manufacturer, his authorised representative or under the supervision
of authorised inspectors.
For systems in hazardous areas, regular tests are required in order to maintain the proper
condition.
The following checks are recommended:
•Check the housing, the cable entries and the feed lines for corrosion and/or damage.
•Check the NPT adapter after maintenance work, that this has not become loose on the device.
•Check the measuring unit and the piping connections for leakage.
•Check the measuring unit and the indicator for dust deposits.
•Include the flowmeter in the regular pressure test of the process line.
During re-assembly after maintenance of the indicator/converter (or replacement) or
the flowmeter, the operator must take appropriate measure to ensure that
•no charge is applied to the surface of the housing.
•no charge is applied to the inner surfaces of the housing.
•any damaged gaskets are replaced.
The cover is to be closed following maintenance work on the indicator.
Cleaning the measuring unit
Depending on the application, worst-case operating conditions may lead to reduced measuring
performance as a result of fouling of the measuring system. Clean the measuring unit in
accordance with the standard manual for non-explosion protected versions.
The measuring unit must be dismantled for cleaning. This dismantling will need to be
coordinated with operating conditions (e.g. check for existence of a flammable liquid or explosive
atmosphere in or at the tank or pressurised tank) and is within the responsibility of the operator.
To do this, follow the instructions for exchanging the entire device (for details refer to
Dismantling on page 20).
CAUTION!
When opening the indicator or terminal compartment, the operator must ensure there is a
controlled environment that prevents dirt or similar from penetrating into the device. Following
connection or maintenance, the operator must ensure that the inside of the device is cleaned
with suitable agents.

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DK32 - DK34
www.krohne.com 12/2019 - 4007138001 - AD DK32-34 Exi Gb-Db R01 en
6.2 Dismantling
Replacing the display
Due to the modular design of the variable area flowmeter, from a safety perspective it is possible
to replace a complete display with an identical spare part.
Exchanging the entire device
The dismantling and installation is within the responsibility of the operator.
Exchanging and dismantling should take place in a de-energised state, if at all possible. If that is
not possible, the basic conditions for intrinsic safety (e.g. no grounding or connection of different
intrinsically safe circuits to one another) must be observed during dismantling.
CAUTION!
There may be a loss of measuring accuracy!
CAUTION!
• Pressurised pipes have to be depressurised before removing the measuring unit.
• In the case of environmentally critical or hazardous products, appropriate safety precautions
must be taken with regard to residual liquids in the measuring unit.
• New gaskets have to be used when re-installing the device in the piping.