COMAC CAL FLOW 33Exia MGD Use and care manual

FLOW 33Exia MGD
1.10
Installation and technical conditions
Date of issue 12/12/2016

FLOW 33Exia Manual Page 2 (total 33) COMAC CAL s.r.o.
Contents:
Description of device .............................................................................................................................3
Scope of delivery................................................................................................................................3
Storage conditions.................................................................................................................................5
Warranty................................................................................................................................................5
Installation in pipeline ..........................................................................................................................6
Important information for selection of location.................................................................................6
Sources of disturbances......................................................................................................................6
Installation examples..........................................................................................................................7
Actual installation in pipeline ............................................................................................................8
Installation check..............................................................................................................................13
Wiring ..................................................................................................................................................14
Meter wiring.....................................................................................................................................14
Wiring check ....................................................................................................................................17
Putting into operation .........................................................................................................................18
Technical data .....................................................................................................................................20
Safety information...............................................................................................................................22
Factory settings....................................................................................................................................24
Table with flow ranges for individual DN sizes .................................................................................25
Basic sensor sizes.................................................................................................................................26
Nomogram for quick proposal of the measured place.......................................................................30
Reduction in DN pipe..........................................................................................................................30
Failures and their symptoms during measurement ...........................................................................31
Flow sensor cleaning...........................................................................................................................31
Service..................................................................................................................................................31
Order code............................................................................................................................................32
Form for returning the meter to COMAC CAL s.r.o.........................................................................33

FLOW 33Exia Manual Page 3 (total 33) COMAC CAL s.r.o.
Description of device
The FLOW 33Exia meter is based on measurement principle by a well-known Faraday's
electromagnetic induction law according to which an electric voltage is induced during the flow of a
conductive liquid through the flow meter magnetic field. This is picked up by two electrodes in direct
contact with the measured medium and evaluated in the electronic unit.
The FLOW 33Exia type of induction meters are suitable exclusively for measurement of volumetric
flow of electrically conductive liquid substances with a minimum conductivity of 20 S/cm (at a
lower conductivity, upon agreement with the manufacturer).
Meters are designed for flow measurement where the velocity of liquid is in the range of 0.01 ÷ 12
m/s. The best measurement accuracy can be obtained in the range of 1 ÷ 10 m/s.
Flow 33Ex are firmly integrated in the pipe system of underground mine, chemical or other
application where exist the risk of explosive gases and dusts. They are formed by corundum
measuring pipe in diameter DN 15, DN 25, DN 32, DN 40, DN 50, DN 65 and DN 80 or stainless
steel measuring pipe with rubber or PTFE lining in DN15, DN 20, DN 25, DN 32, DN 40, DN 50,
DN 65, DN 80, DN 100, DN 125, DN 150 and DN 200. Pipes are inside stainless steel housing fitted
with different types of process connection. On the housing is fixed stainless steel cover for evaluation
unit with electronics of sensor, which is fitted with stainless steel top cover equipped with connector
for wiring of flowmeter to next devices.
The entire inner space of flowmeter is filled with sealing compound for protection against humidity
and increase protection against ignition of surrounding atmosphere in the hazardous area. Therefore,
after filling of the whole system is flowmeter disassembled and any changes in construction are not
possible.
Scope of delivery
Accessories vary according to the variant of flow sensor and above standard optional features.
Threaded design
Electronic evaluation unit in a compact design (the electronic unit is integral part of the flow sensor),
flow sensor, connecting grounding cable, installation manual.
Sandwich design
Electronic evaluation unit in a compact design (the electronic unit is integral part of the flow sensor),
flow sensor, bolts for installation of the sensor between flanges (quantity as per tightening torque
table, see below) with nuts and washers, connecting grounding cable, installation manual.
Flanged design
Electronic evaluation unit in a compact design (the electronic unit is integral part of the flow sensor),
flow sensor, connecting grounding cable, installation manual.
Food industry design
Electronic evaluation unit in a compact design (the electronic unit is integral part of the flow sensor),
flow sensor, adapter piping connection according to DIN 11851, installation manual.

FLOW 33Exia Manual Page 4 (total 33) COMAC CAL s.r.o.

FLOW 33Exia Manual Page 5 (total 33) COMAC CAL s.r.o.
Storage conditions
The temperature during transportation and storage of the meter must be within the range of -10 °C to
50 °C.
Wooden boards installed on the flanges in the factory are used for protection of lining on the flanges
during storage and transportation (for PTFE lining). Remove these protective boards just before
installing in the pipeline!!!
Do not lift the flanged meters by the transducer head or by the connecting box of the detached design
during transportation! Use slings and place them round both process connections for transportation of
meters up to DN125 (chains may damage the meter head)! Use only the metallic lugs on the flange
for transportation, lifting and installation of the sensor in piping in case of DN150 and bigger!!!
Warranty
Unprofessional installation or using the induction meters (devices) may result in a loss of warranty as
well as failure to comply with installation or operating conditions according to this manual.
In case of returning the meters for inspection or repair to the COMAC CAL s.r.o. factory, enclose
please the completed form, see the last page of this manual. Without having one, we will not be able
to handle your requirement for modification or possibly repair your meter correctly and promptly.

FLOW 33Exia Manual Page 6 (total 33) COMAC CAL s.r.o.
Installation in pipeline
Important information for selection of location
Outdoor conditions
It is necessary to ensure that the flow sensor is not exposed to weather effects and that the measured
medium cannot freeze in the flow sensor as it would damage the measuring tube.
In case of outdoor location of the electronic evaluation unit, the manufacturer recommends using a
protective box or a roof to avoid direct solar exposure so that the evaluation electronics cannot get
overheated.
Operating ambient temperature (full function) from 0 °C to + 44 °C
Limited increased ambient temperature (without function) up to + 55 °C
Limited decreased ambient temperature (without function)) up to - 30 °C
Relative ambient humidity with 25 °C up to 100 %
Based on characteristic of the used components is F33 Ex placed in a group II.B with maximal
temperatue < 60 °C
Sources of disturbances
The following items rank among the most frequent sources of disturbances to the steady flow of
liquid:
Abrupt changes in pipe cross-section if not performed as a cone with an angle of 7° (where
is the angle made by bevelled walls of the pipe reduction).
Incorrectly centred sealing, low ID sealing or sealing made of soft elastic materials which are
pushed out into the interior pipe cross-section after flanges are tightened.
Anything interfering in the flow of liquid, for example thermowells, branch pipes, T-pieces,
bends, elbows, slide valves, cocks, flap valves, shut-off valves, control valves, butterfly valves
and check valves. Pipe outlets from tanks, heat exchangers and filters.
No intensive magnetic fields in the proximity of the induction flow sensor (detector) must be
present.
No sources of disturbances affecting the steady flow must be present in the straight pipeline
sections. They must be located in the piping after the flow sensor or at the farthest distance before it.
Sources of disturbances may substantially reduce the measuring range and accuracy of the flow
meters.
Vibration
We recommend supporting the connecting pipes on both sides of the meter for partial elimination of
vibrations. Levels and range of vibrations must be under 2.2 in the frequency range of 20 ÷ 50 Hz
according to IEC 068-2-34. If the pipeline is exposed to excessive vibrations (e.g. from pumps),
using compact meters is not recommended.
Actual location
The flow sensor (detector) must not be at the top position of the pipe which may be airlocked, or in
declining or even in horizontal pipelines with open ends in which air may penetrate. Impurities may
accumulate during long-term measurement of very low flow rates Q < 0.1 m/sec. There must be a

FLOW 33Exia Manual Page 7 (total 33) COMAC CAL s.r.o.
sufficient pressure in the place of flow sensor installation so that the expulsion of gas or vapour
bubbles from the liquid is avoided. Little bubbles that always occur in liquids may accumulate at any
of the electrodes and this may result in incorrect operation of the meter. Gas bubbles are expelled
also at an abrupt pressure drop. Therefore, butterfly valves and similar elements should be located
after the flow sensor. For the same reason, the flow sensor should not be placed at the suction side
of the pump. To prevent the bubbles from accumulation at a low flow in the flow sensor, it is
suitable, e.g. that the pipe is slightly ascending or that the flow sensor is located in the vertical
section of the pipeline.
It is necessary for proper function of the meter, to fill up the flow sensor with the fluid to be
measured so that erroneous readout of quantity of liquid passing through the meter can be avoided
when the pipe is empty. It is necessary to select the location of the meter in such a way that the flow
sensor aeration can be avoided. In the case of an open system, the flow sensor is placed in the
bottom position of the U-profile pipework, ensuring that the fluid will not flow out of the sensor.
In case of any intervention into the measuring circuit must be accessed like a pipe is fulfilled of
medium, and regardless of the displayed information “empty pipe test” on the meter LED !!!
Installation examples
Trouble-free and exact operation of the meter is dependent on its correct location in the system. The
most frequent methods of the placement are shown in the following figures:
Recommended installation locations Downtake pipe
Horizontally laid pipeline Long pipeline
Install an air bleed valve
after the sensor
Place the sensor in a slightly
ascending pipeline
Pipeline is
empty;
erroneous
measurement
Correct
location
Install controls and shut-off
valves always after the sensor
Bubbles are accumulated in the
pipeline; erroneous measurement

FLOW 33Exia Manual Page 8 (total 33) COMAC CAL s.r.o.
Free inlet or outlet Pumps
The flow of liquid flow in the flow sensor should be steady and free of whirling. For this reason,
straight sections of pipeline with the same ID as that of the flow meter before and after the flow
sensor (with permissible deviation of +5%). Recommended minimum length of straight sections is
5d before the flow sensor and 3d after the flow sensor where d is the inside diameter of the meter
in millimetres. The same principles apply before and after the flow sensor in case of bi-directional
flow measurement.
Recommendations
In case of whirled up flow, extend the calming sections of pipeline or integrate a flow
conditioner.
When blending a mixture of substances, it is necessary to install the flow meter either before
the point of blending or at a sufficient distance after it (30d min. where d is the inside
diameter of the meter in millimetres), otherwise it will result in instability of indication.
When plastic pipeline is used or in case of metallic pipes with internal non-conductive layer,
earthing rings are needed.
Do not install the sensor at the suction side of the pumps; this will eliminate the risk of
vacuum and possible damage to the measuring tube lining.
Pumps, bends and elbows found closely in succession in various levels should be at a distance
of 20d at least before the flow sensor. In case of a separate elbow or bend, the placement
10d before the meter is recommended.
When piston pumps, diaphragm pumps, and flexible tube pumps are used, it is necessary to
install a pulse damper in the system.
In order to provide the highest accuracy, it is important to ensure permanent flooding for the
sensor (for example, by installation of the sensor in the U-shaped pipeline) even if the sensor
is equipped with empty tube test. This will serve as an additional safety measure for detection
of non-flooded tube.
The responsibility for suitability and adequacy of application of induction flow meters is borne by
the designer or possibly the user himself.
Actual installation in pipeline
When welding both counter-flanges to the pipelines, it is necessary to maintain their alignment so
that levelness of bearing surfaces of the flanges onto the front faces of the detector is ensured (at the
same time, this must not be achieved by unequal tightening of the bolts as there is a risk of leakage
due to thermal loading in the future or the measuring tube may break during such tightening). The
difference of LMAX and LMIN distances of the sealing surfaces of the flanges before the flow sensor is
installed must not be greater than 0.5 mm.
Built in the U-shaped pipeline
The flow meter must not be installed
in the suction side of the pump
free flow

FLOW 33Exia Manual Page 9 (total 33) COMAC CAL s.r.o.
The opposition of the holes in the counter-flanges for the bolts should be ensured in the same manner
and a sufficient room behind the flanges should be available for the bolts and nuts so that the actual
installation of the sensor in pipeline and its attachment with the bolts is made possible.
The manufacturer recommends using an intermediate piece during welding. It is absolutely excluded
to use the flow sensor as an intermediate piece due to thermal damage. The welding current must not
run through the flow sensor during electrical welding. The installation of the flow sensor is carried
out after welding, coating, building and similar works are completed.
The actual installation is performed by the fixation between the counter-flanges that are welded to
the calming pipeline (5×d before and 3×d in the direction of flow) whereas the liquid must run
through the flow sensor in the direction indicated by the arrow on the sensor name plate.
During installation, do not lift the meter by the evaluation unit housing, possibly under the meter's
metallic housing but always use slings round the process connection or use the lifting lugs on the
flanges.
Installation position
The inductive flow sensor is installed in arbitrary position in vertical piping. In case of horizontal
piping, it is necessary to make sure that the sensor is installed with its measuring electrodes in
horizontal position.
Installation in piping and placement of measuring electrodes in flow sensor

FLOW 33Exia Manual Page 10 (total 33) COMAC CAL s.r.o.
During installation, beware of:
-dropping the meter onto the ground and damaging the measuring tube or electronics
-contamination of the electrodes (do not touch the electrodes, otherwise they get
contaminated)
-when additional sealing is used, avoid its interference in the flow profile of the detector
between the flanges and the pipeline, otherwise the flow measurement error may be
increased
Tightening torques
It is absolutely necessary to tighten the bolts and nuts equally by alternating sides and in the order
shown in figure applying the maximum torque according to the table.
If the bolts are tightened too much during the installation of pipework components, deformation of
the sealing surface may occur. In consequence, the torque values indicated in the table are used as a
guidance for tightening the screws and bolts.
Table with tightening torques for screws/bolts:
Diameter
nominal
PN 10
PN 16
DN
Screws
Tightening torque [Nm]
Screws
Tightening torque [Nm]
Rubber
PTFE
Rubber
PTFE
15
4 x M12
20
25
4 x M12
20
25
20
20
25
20
25
25
20
25
20
25
32
4 x M16
20
25
4 x M16
20
35
40
20
25
20
35
50
20
45
20
45
65
20
46
20
46
80
8 x M16
20
48
8 x M16
20
48
100
20
50
20
50
125
20
80
20
80
150
8 x M20
24
90
8 x M20
27
90
200
25
115
12 x M20
28
80
250
12 x M20
27
95
12 x M24
38
110
300
34
115
55
150
350
16 x M20
47
140
16 x M24
75
160
400
16 x M24
65
155
16 x M27
85
200