Bühler technologies GAS 222.31 Ex2 Owner's manual

Gas Analysis
Installation and Operation Instructions
Original instructions
Sample gas probes
GAS 222.31 Ex2
BE460052
03/2022
Bühler Technologies GmbH, Harkortstr. 29, D-40880 Ratingen
Tel. [phone] / 49 89-0, Fax: [phone] / 49 89-20
E-Mail: [email protected]
Internet: www.buehler-technologies.com

Bühler Technologies GmbH, Harkortstr. 29, D-40880 Ratingen
Tel. [phone] / 49 89-0, Fax: [phone] / 49 89-20
Internet: www.buehler-technologies.com
E-Mail: [email protected]
Read this instruction carefully prior to installation and/or use. Pay at-
tention particularly to all advises and safety instructions to prevent in-
juries. Bühler Technologies can not be held responsible for misusing
the product or unreliable function due to unauthorised modifications.
All rights reserved. Bühler Technologies GmbH 2023
Document information
Document No..........................................................BE460052
Version.........................................................................03/2022

GAS 222.31 Ex2
Table of Contents
1 Introduction.....................................................................................................................................................................................................................2
1.1 Intended Use.........................................................................................................................................................................................................2
1.2 Type Plate...............................................................................................................................................................................................................2
1.3 Contents................................................................................................................................................................................................................. 2
1.4 Ordering instructions......................................................................................................................................................................................... 3
1.5 Product Description............................................................................................................................................................................................4
2 Safety instructions ......................................................................................................................................................................................................... 5
2.1 Important Information...................................................................................................................................................................................... 5
2.2 General Hazard Warnings ................................................................................................................................................................................6
2.3 Special conditions for safe use ........................................................................................................................................................................ 7
2.4 Ambient Temperature range of the equipment........................................................................................................................................ 7
3 Transport and storage ..................................................................................................................................................................................................8
4 Installation and connection ........................................................................................................................................................................................9
4.1 Installation site requirements.........................................................................................................................................................................9
4.2 Installation ............................................................................................................................................................................................................9
4.3 Installing the upstream filter ..........................................................................................................................................................................9
4.4 Insulation...............................................................................................................................................................................................................9
4.5 Connecting the Gas Line..................................................................................................................................................................................10
4.5.1 Blowback Connection.........................................................................................................................................................................11
4.5.2 Connecting the calibrating gas line (optional)........................................................................................................................... 11
4.6 Connecting the Backwashing System and the Compressed Air Cylinder (Optional) .....................................................................11
4.7 Electrical Connections...................................................................................................................................................................................... 12
4.7.1 Version Without Terminal Box....................................................................................................................................................... 12
4.7.2 Version With Terminal Box ............................................................................................................................................................. 12
4.7.3 Connecting the Temperature Switch ........................................................................................................................................... 12
4.7.4 Connecting the Earth Conductor/Earthing................................................................................................................................ 13
4.7.5 Solenoid Valves (Optional) .............................................................................................................................................................. 13
4.7.6 Limit Switch (Optional)..................................................................................................................................................................... 13
5 Operation and Control................................................................................................................................................................................................ 14
5.1 Before Startup .................................................................................................................................................................................................... 14
6 Maintenance...................................................................................................................................................................................................................15
6.1 Maintaining the filter element .....................................................................................................................................................................16
6.1.1 Replacing the upstream filter ........................................................................................................................................................ 16
6.2 Backwashing the Intake Filter (within the process stream)...................................................................................................................17
6.2.1 Manual Blowback (Without Blowback Control).........................................................................................................................17
6.2.2 Automatic Blowback (External Blowback Control)....................................................................................................................17
6.3 Maintenance Schedule .................................................................................................................................................................................... 18
7 Service and repair......................................................................................................................................................................................................... 19
7.1 Troubleshooting ................................................................................................................................................................................................ 19
7.2 Spare Parts and Accessories ........................................................................................................................................................................... 19
8 Disposal .......................................................................................................................................................................................................................... 20
9 Appendices ..................................................................................................................................................................................................................... 21
9.1 Technical Data.................................................................................................................................................................................................... 21
9.2 Connection Diagram ........................................................................................................................................................................................22
9.3 Terminal Diagram Probe Terminal Box ......................................................................................................................................................22
9.4 Terminal Diagram Terminal Box Limit Switch .........................................................................................................................................23
9.5 Flow chart ............................................................................................................................................................................................................23
9.6 Dimensions .........................................................................................................................................................................................................24
9.7 List of chemical resistance ..............................................................................................................................................................................26
9.8 User book (Please make copies).....................................................................................................................................................................27
10 Attached Documents...................................................................................................................................................................................................28
iBühler Technologies GmbHBE460052 ◦ 03/2022

GAS 222.31 Ex2
1 Introduction
1.1 Intended Use
The sample gas probe is intended for installation into gas analysis systems in commercial applications.
It may be operated in a Zone 2, explosion class IIC, explosive gas atmosphere which is rarely and only temporarily explosive. Zone
2 explosive gas atmospheres may be extracted with or transported with these probes. The probe has a temperature switch
which may only be operated as simple electrical equipment on an intrinsically-safe circuit supplied by a type-tested switch amp-
lifier.
The explosion protection markings on the probes are:
ATEX: II 3G Ex ec ic mb1 IIC T3/T4 Gc
IECEx: Ex ec ic mb1 IIC T3/T4 Gc
1 Only for versions with solenoid valve.
Sample gas probes are among the main components in a gas conditioning system.
– Therefore also note the related drawing in the data sheet in the appendix.
– Before installing the device, verify the listed technical data meet the application parameters.
– Further verify all contents are complete.
Please refer to the type plate to identify your model. In addition to the job number it also contains the item number and model
designation.
Please note the specific values of the device when connecting, and the correct versions when ordering spare parts.
Passing through gases
Flammable gases above the UEL (upper explosion limit) may only be blown back with inert gases. Flammable gases from 25% LEL
(lower explosion limit) and up to the LEL may be blown back provided the operator ensures the blown back gas is not and cannot
be explosive. For safety reasons we recommend only using inert gases in these cases as well.
Blowing back explosive atmospheres (range from LEL to UEL) with the probes is prohibited due to possible adiabatic compres-
sion (high blowback pressure against contaminated filter). The operator is responsible for compliance with these conditions tak-
ing into account his risk assessment.
1.2 Type Plate
Example:
GAS 222.31 Ex2
000053273 462223110192331111111 001
Manufacturer and address
Model designation
Order no., item no.
Blast protection marking
Electrical supply
IECEx certificate number
Year of manufacture
II 3G Ex ec ic IIC T4 Gc
115/230V 50/60Hz;Valves:24V UC
IECEx IBE 17.0002X
Read manual! Year: 2017
Bühler Technologies GmbH
Harkortstr. 29 D-40880 Ratingen
1.3 Contents
– 1 x Sample gas probe
– 1 x Flange gasket and screws
– Product documentation
– Connection and mounting accessories (only optional)
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GAS 222.31 Ex2
1.4 Ordering instructions
The item number is a code for the configuration of your unit. Please use the following model key:
4622231 X 0 X X X X 3 X X X X X X X Product characteristics
Junction box
0 No
1 Yes
Flange
0 1 Flange DN65 PN6
0 2 Flange DN3"-150
Hazardous area Outside and Inside
2 9 Ex-Zone 2 outside, none inside
2 2 Ex-Zone 2 outside and inside
Temperature class
3 T3
4 T4
Power supply sample probe
3 115/230 V
Low temperature alarm
1 Opener (open at operating temperature) (marked with "ic")
2 Closer (closed at operating temperature) (marked with "ic")
Calibration gas port
0 No
1 6 mm
2 6 mm with check valve
3 1/4"
4 1/4" with check valve
Capacitive vessel *
0 No
1 Yes
Valve for pressurized air *
0 Ball valve
1 Solenoid valve 110 V (marked with "mb")
2 Solenoid valve 230 V (marked with "mb")
3 Solenoid valve 24 V (marked with "mb")
9 none
Pneumatic actuator for internal ball valve
0 No
1 Mono stable depressurized open
2 Mono stable depressurized closed
Limit switch for pneumatic actuator
0 No
1 Yes
Solenoid valve for pneumatic actuator
0 No
1 110 V (marked with "mb")
2 230 V (marked with "mb")
3 24 V (marked with "mb")
* Blowback of explosive atmosphere prohibited.
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GAS 222.31 Ex2
1.5 Product Description
The probe is equipped with self-regulating PTC heating cartridges and a temperature contact.
Probe Description
GAS 222.31 Ex2 Probe with upstream filter, shut-off valve and blowback connection
GAS 222.31-JB Ex2 Probe with upstream filter, shut-off valve, blowback connection and terminal box
Accessories Please refer to the data sheet at the end of this manual for accessories for this probe
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GAS 222.31 Ex2
2 Safety instructions
2.1 Important Information
This unit may only be used if:
– the product is being used under the conditions described in the operating- and installation instructions, used according to
the nameplate and for applications for which it is intended. any unauthorized modifications to the device will void the war-
ranty provided by Bühler Technologies GmbH,
– the limits in the data sheet and the instructions must be observed,
– the temperature switch is being operated on an intrinsically-safe circuit,
– the controller itself is installed outside the explosive area,
– the handle including O-ring are installed at a suitable ambient temperature range and filter (where applicable),
– monitoring equipment / protection devices must be connected correctly,
– service and repairs not described in these instructions is performed by Bühler Technologies GmbH,
– using genuine replacement parts.
Regulation IEC/EN60079-14 must be observed when erecting electrical systems in explosive areas.
Additional national regulations pertaining to initial operation, operation, maintenance, repairs and disposal must be observed.
These operating instructions are a part of the equipment. The manufacturer reserves the right to change performance-, specific-
ation- or technical data without prior notice. Please keep these instructions for future reference.
Signal words for warnings
DANGER
Signal word for an imminent danger with high risk, resulting in severe injuries or death if not avoided.
WARNING
Signal word for a hazardous situation with medium risk, possibly resulting in severe injuries or death if not
avoided.
CAUTION
Signal word for a hazardous situation with low risk, resulting in damaged to the device or the property or
minor or medium injuries if not avoided.
NOTICE
Signal word for important information to the product.
Warning signs
These instructions use the following warning signs:
Warns of a general hazard General notice
Warns of voltage Unplug from mains
Warns not to inhale toxic gasses Wear respiratory equipment
Warns of corrosive liquids Wear a safety mask
Warns of explosive areas Wear gloves
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GAS 222.31 Ex2
2.2 General Hazard Warnings
The maximum surface temperatures of the probes also vary based on operating conditions (steam temperature, sample gas in-
let temperature, ambient temperature, fluid flow rate). When used in explosive areas, also particularly note the related hazard
warnings.
The equipment must be installed by a professional familiar with the safety requirements and risks.
Be sure to observe the safety regulations and generally applicable rules of technology relevant for the installation site. Prevent
malfunctions and avoid personal injuries and property damage.
The operator of the system must ensure:
– Safety notices and operating instructions are available and observed,
– The respective national accident prevention regulations are observed,
– The permissible data and operational conditions are maintained,
– Safety guards are used and mandatory maintenance is performed,
– Legal regulations are observed during disposal,
– compliance with national installation regulations.
Maintenance, Repair
Please note during maintenance and repairs:
– Repairs to the unit must be performed by Bühler authorised personnel.
– Only perform conversion-, maintenance or installation work described in these operating and installation instructions.
– Always use genuine spare parts.
– Do not install damaged or defective spare part. If necessary, visually inspect prior to installation to determine any obvious
damage to the spare parts.
Always observe the applicable safety and operating regulations in the respective country of use when performing any type of
maintenance.
NOTICE Accessories may limit critical operating parameters of the base unit
Adding accessories may limit critical operating parameters. Ambient temperatures, zone
classifications, explosion groups, temperature classes or chemical resistances of ac-
cessories may vary from the base unit.
Always include all technical data in the operating instructions and data sheets of all
components in the safety assessment.
NOTICE When used in explosive areas
Regulation IEC/EN60079-14 must be observed when erecting electrical systems in ex-
plosive areas.
Additional national regulations pertaining to initial operation, operation, maintenance,
repairs and disposal must be observed.
DANGER Electrical voltage
Electrocution hazard.
a) Disconnect the device from power supply.
b) Make sure that the equipment cannot be reconnected to mains unintentionally.
c) The device must be opened by trained staff only.
d) Regard correct mains voltage.
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GAS 222.31 Ex2
DANGER Toxic, corrosive gas/condensate
Sample gas/condensate may be hazardous to health.
a) If necessary, ensure a safe gas/condensate discharge.
b) Always disconnect the gas supply when performing maintenance or repairs.
c) Protect yourself from toxic/corrosive gasses/condensate when performing mainten-
ance. Wear appropriate protective equipment.
DANGER Explosion hazard
Life and explosion risk may result from gas leakage due to improper use.
a) Use the devices only as described in this manual.
b) Regard the process conditions.
c) Check tubes and hoses for leakage.
DANGER Danger to life and explosion during installation and maintenance
The unit must not be worked on (assembly, installation, maintenance) in explosive at-
mospheres.
DANGER
Use in explosive areas
Flammable gasses could ignite or explode. Avoid the following hazard sources:
Application area!
Never operate the gas probe outside the specifications. Extracting gases or gas mixtures
which are also explosive in the absence of air is prohibited.
Electrostatic charge (sparking)!
The equipment may only be used where normal operating conditions do not frequently
produce flammable, electrostatic discharge.
Always clean plastic housing parts and decals with a damp cloth.
Sparking!
Protect the M3 connectors from external blows.
Flame propagation!
If the process holds a risk of flame propagation, install a flame arrestor.
Adiabatic compression (explosion hazard)
Adiabatic compression may cause high gas temperatures during blowback. Never blow-
back if gases are explosive. Only use nitrogen (inert gas) to blowback flammable gas.
2.3 Special conditions for safe use
The temperature switch must be operated intrinsically safe. See parameters in chapter “Connecting the Temperature Switch”.
2.4 Ambient Temperature range of the equipment
The ambient temperature range may be limited based on the version. Please note the Ambient temperature ranges under
"Technical Data".
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GAS 222.31 Ex2
3 Transport and storage
Only transport the product inside the original packaging or a suitable alternative.
The equipment must be protected from moisture and heat when not in use. They must be stored in a covered, dry and dust-free
room at a temperature between -20°C to 50°C (-4°F to 122°F).
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GAS 222.31 Ex2
4 Installation and connection
NOTICE Accessories may limit critical operating parameters of the base unit
Adding accessories may limit critical operating parameters. Ambient temperatures, zone
classifications, explosion groups, temperature classes or chemical resistances of ac-
cessories may vary from the base unit.
Always include all technical data in the operating instructions and data sheets of all
components in the safety assessment.
4.1 Installation site requirements
Sample gas probes are intended for flange mounting.
– Installation site and installation position are determined based on requirements specific to the application.
– If necessary, the connection piece should be slightly tilted toward the centre of the channel.
– The installation site should be protected from the weather.
– In addition, adequate and safe access for installation and future maintenance work should be provided. Particularly follow
the uninstalled size of the probe tube!
If the probe is transported to the installation site in pieces, it will first need to be assembled.
4.2 Installation
DANGER Danger to life and explosion during installation and maintenance
The unit must not be worked on (assembly, installation, maintenance) in explosive at-
mospheres.
DANGER Explosion hazard
When used in explosive areas
Flammable gasses and dust could ignite or explode.
Never operate the gas probe outside the specifications. Extracting gases or gas mixtures
which are also explosive in the absence of air is prohibited.
DANGER Explosion hazard due to flame propagation
Severe injuries and damage to the system
If the process holds a risk of flame propagation, install a flame arrestor.
4.3 Installing the upstream filter
The upstream filter, if necessary with matching extension, must be screwed in. The probe is then attached to the mating flange
using the included seals and screws.
4.4 Insulation
On heated probes completely insulate any exposed flange areas and, if applicable, the connection piece to absolutely prevent
thermal bridges. The insulating material must meet the application requirements and be weatherproof.
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GAS 222.31 Ex2
4.5 Connecting the Gas Line
The sample gas line must be carefully and properly connected using a suitable fitting.
This table provides an overview of the sample gas probe connections:
Probe
GAS 222
Reservoir
PAV01
Ball valve
pneumatic drive
Control valve
3/2-way solenoid
valve
Connecting flange 1) DN65/PN6/
DN3"-150
Sample gas inlet G3/4
Sample gas outlet NPT 1/4
Blowback connection G3/8
Test gas connection 1) Tube Ø6 mm
Tube Ø1/4
Filling port NPT 1/4
Condensate G1/2
Bypass NPT 1/4
Control air G1/8 G1/4
NPT 1/4
Tab.1: Gas Probe Connections (Varies by Model)
1) Varies by version.
Please note the following items when connecting the sample gas line (NPT 1/4") on heated probes to prevent thermal bridges:
– Choose the shortest possible screw connection.
– Shorten the connection pipe for the sample gas line as much as possible. To do so, remove the insulation around the sample
gas line. This is done by loosening the fixing bolts.
CAUTION Fragile
The insulation is fragile. Handle with care, do not drop.
After connecting the sample gas line it must be braced and secured with the clamp.
Long sample gas lines may require additional support clamps along the way to the analysis system! Once all lines have been
connected and checked for leaks, carefully reinstall and secure the insulation.
WARNING Gas emanation
Sample gas can be harmful to the health!
Check the lines for leaks.
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GAS 222.31 Ex2
4.5.1 Blowback Connection
Without accessories installed for the blowback device, the blowback connection comes with a sealed G3/8 screw-in connection. If
you require blowback, you will need to undo this screw-in connection and ensure the blowback line is connected properly and
tight.
DANGER Toxic, corrosive gasses
Explosive or toxic gases can develop due to a leaking or open blowback connection.
4.5.2 Connecting the calibrating gas line (optional)
Connecting the calibrating gas line requires a Ø6 mm or Ø1/4” pipe fitting.
If the calibrating gas connection was ordered with check valve, a Ø6 mm or Ø1/4” pipe can be connected directly to the check
valve.
4.6 Connecting the Backwashing System and the Compressed Air Cylinder
(Optional)
The air lines must be connected carefully and properly, using suitable fittings.
If the probe is equipped with pressure vessel for efficient blowback (optional), a manual shut-off valve (ball valve) must be in-
stalled in the air supply, immediately upstream from the pressure vessel.
On probes used to sample flammable gas, nitrogen (inert gas) must be used for blowback. Blowback of explosive gases is prohib-
ited.
NOTICE
The operating pressure of the compressed air (inert gas) required for blowback must al-
ways be higher than the process pressure.
Required pressure differential min. 3 bar (44 psi).
DANGER Broken pressure vessel
Gas leak, danger due to flying parts.
Maximum operating pressure of the pressure vessel 10 bar (145 psi)!
The operating pressure reduces based on the operating voltage (see solenoid valve type
plate).
DANGER Adiabatic compression during gas blowback (explosion hazard)!
Adiabatic compression may cause high gas temperatures and must be checked by the
user.
Gas blowback may result in high gas temperatures due to adiabatic compression. This
can cause flammable gases to ignite spontaneously.
a) Blowback of explosive atmosphere / gases is prohibited.
b) Flammable atmosphere / gases (non-explosive) may only be blown back with nitro-
gen (inert gas).
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GAS 222.31 Ex2
4.7 Electrical Connections
WARNING Hazardous electrical voltage
The device must be installed by trained staff only.
CAUTION Wrong mains voltage
Wrong mains voltage may damage the device.
Regard the correct mains voltage as given on the type plate.
CAUTION Equipment damage
Cables damaged
Do not damage the cable during installation. Install a strain relief for the cable connec-
tion. Secure the cable against twisting and loosening. Please note the temperature res-
istance of the cables (> 100°C/212°F).
Only use cables with a temperature resistance of >100°C (212°F) to connect to power. Make sure the connecting cable has suffi-
cient strain relief (match cable diameter to the seal on the cubic plug/cable fitting).
Please note, the heating system briefly has high starting currents (max. 6A). Use a suitable fuse (8A). When connecting, also ob-
serve the applicable explosion protection regulations (e.g. IEC/EN 60079-14).
4.7.1 Version Without Terminal Box
The probe includes two cubic plugs per EN 175301-803. The plug is configured so it cannot be connected reversed. For safety reas-
ons this configuration must not be modified.
One plug is used to power the two heating cartridges (power supply (115/230) VAC, 50/60Hz, see type plate), the other plug is for
the temperature switch (alarm output).
The supply line cross-sections must be suitable for the rated current. Use a maximum line cross-section of 1.5mm2 and a cable
diameter of 8-10mm.
Connect the power supply and the intrinsically-safe temperature switch per the connection diagram.
Connect optional probe accessories directly to the respective power supply.
4.7.2 Version With Terminal Box
This probe version includes a terminal box. All electrical connections are factory connected to the terminals in the terminal box.
Connect the respective power supply for the two heating cartridges, the intrinsically-safe temperature switch and the optional
accessories to the terminals per the connection diagram.
The probe may only be operated using the Ex e cable fittings and the terminal box closed. Never change the terminal assign-
ment.
4.7.3 Connecting the Temperature Switch
According to IEC/EN60079-11 the temperature switch in this probe is a simple electrical equipment and to be considered a
purely ohmic circuit. It may only be operated with a type-tested controller with an intrinsically-safe circuit.
Temperature switch connection data:
Ui = 30V; Ii = 100mA; Ci = 0; Li = 0
Never exceed the connection data!
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GAS 222.31 Ex2
4.7.4 Connecting the Earth Conductor/Earthing
Always connect all of the designated connections on your unit to your protective conductor system. Connect the earth to the ad-
ditional equipotential bonding conductor connection on the housing.
4.7.5 Solenoid Valves (Optional)
DANGER Explosion hazard when opening the solenoid valve housing
The solenoid valve is a closed system. It must not be removed!
A fuse suitable for the rated current (max. 3 x Ib per IEC60127-2-1) or a protective motor switch with short circuit and fast
thermal response (set for rated current) must be connected upstream from each magnet to prevent short-circuits.
– For magnets with a very low rated current, a fuse of the lowest current value under the IEC standard will suffice. This fuse
must be connected separately, upstream.
– The rated fuse voltage must be equal to or greater than the specified nominal voltage (UN +10%) of the magnet. The fuse rat-
ing is specified in the type plate of the solenoid valve.
– The limiting breaking capacity of the fuse element must be equivalent to or greater than the maximum short-circuit current
expected at the installation site (typically 1500A).
DANGER Potential equalization/static charge
Static charges can result in incendive sparking.
Avoid static charges. All conductive probe parts must be earthed!
The housing has a connection for an earth/equipotential bonding conductor. Ensure the
housing is adequately earthed (minimum conductor cross-section 4 mm2).
Particularly also observe the requirements of IEC/EN 60079-14!
4.7.6 Limit Switch (Optional)
The optimal limit switch has a separate terminal box with terminals (terminal diagram see "Appendix").
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GAS 222.31 Ex2
5 Operation and Control
NOTICE
The device must not be operated beyond its specifications.
NOTICE
The weather hood must be closed during operation!
WARNING Housing or component damage
Never exceed the maximum working pressure and temperature range of the drive.
DANGER Explosion hazard due to electrostatic discharge
Equipment may only be used where normal operating conditions do not produce fre-
quent flammable, electrostatic discharge.
5.1 Before Startup
Before starting the device, verify:
– The hose- and electrical connections are not damaged and correctly installed.
– No parts of the sample gas probe have been removed.
– The protection and monitoring devices are installed and functional (e.g. flame arrester).
– The gas inlet and outlet on the gas probe are open.
– Ambient parameters are met.
– Probe parts are resistant to media to be conveyed and in the surrounding area.
– The performance specifications in the type plate are met.
– The heater voltage and frequency match the mains values.
– The temperature switch is connected intrinsically-safe.
– The electrical connections are tight.
– The monitoring equipment is connected and set as specified.
– All connection cables are installed without strain.
– Precautions have been taken.
– The earth is proper and functional.
– The downstream filter and the handle with O-ring are installed (if applicable).
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GAS 222.31 Ex2
6 Maintenance
– Damaged parts must be replaced immediately.
– Regularly check the function of the electrical protection.
During maintenance, remember:
– The equipment must be maintained by a professional familiar with the safety requirements and risks.
– Only perform maintenance work described in these operating and installation instructions.
– When performing maintenance of any type, observe the respective safety and operation regulations.
DANGER Danger to life and explosion during installation and maintenance
The unit must not be worked on (assembly, installation, maintenance) in explosive at-
mospheres.
DANGER Electrical voltage
Electrocution hazard.
a) Disconnect the device from power supply.
b) Make sure that the equipment cannot be reconnected to mains unintentionally.
c) The device must be opened by trained staff only.
d) Regard correct mains voltage.
DANGER Toxic, corrosive gases
The measuring gas led through the equipment can be hazardous when breathing or
touching it.
a) Check tightness of the measuring system before putting it into operation.
b) Take care that harmful gases are exhausted to a save place.
c) Before maintenance turn off the gas supply and make sure that it cannot be turned
on unintentionally.
d) Protect yourself during maintenance against toxic / corrosive gases. Use suitable pro-
tective equipment.
DANGER Dangerous electrostatic charge (explosion hazard)
Incendive electrostatic charges may occur when cleaning plastic housing parts and
decals (e.g. with a dry cloth or compressed air). The sparks this produces could ignite
flammable, explosive atmospheres.
Always clean plastic housing parts and decals with a damp cloth!
WARNING Housing or component damage
Never exceed the maximum working pressure and temperature range of the drive.
CAUTION Hot surface
Risk of burns
Depending on the operating parameters, the housing temperature may reach over 100
°C during operation.
Allow the unit to cool down before performing maintenance.
CAUTION Excess pressure
The unit mustn’t be pressurised or energised when opened.
If necessary, close the gas supply and ensure a safe pressure on the process end before
opening.
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GAS 222.31 Ex2
CAUTION Drive pressurised
Never loosen or remove the cover or any accessories with the drive pressurised.
CAUTION Never open the drive with the function “single-acting”!
This may only be done at the manufacturer’s plant.
CAUTION Do not attach levers or tools to the drive’s spindle!
Levers and tools on the spindle can flap around when switching the compressed air or
control voltage back on and cause serious injury or damage!
6.1 Maintaining the filter element
The probes feature a particle filter which needs to be changed as it becomes dirty.
To do so, disconnect the voltage supply and if applicable close the shut-off valve to the process or switch off the process.
CAUTION!Do not damage the rear filter seat.
NOTICE
Ceramic filter elements are very brittle by nature. Handle them with care, don’t let them
fall.
Filter elements made out of sintered stainless steel can be cleaned in an ultrasonic bath
and be used several times as long as both seals are still in proper conditions.
6.1.1 Replacing the upstream filter
The probes are equipped with an upstream filter which is always inside the process stream. The filter is suitable for (Inert gas)
blowback with compressed air, i.e. blowing air (Inert gas) through the filter from the inside to the outside to remove adhering
particles. When sampling flammable gases, nitrogen (inert gas) must be used for blowback. Blowback of explosive gases is pro-
hibited.
The effectiveness of cleaning a filter within a process is directly influenced by the available airflow (amount of gas). We there-
fore recommend using a pressure vessel directly on the probe.
With sufficient upstream filter blowback (within the process stream) the probes are maintenance-free. However, due to process
conditions the filter may clog over time. In this case the filter element will need to be replaced.
To do so, the probe must be completely removed and reinstalled after changing the element.
Condensate inside the pressure vessel
Depending on the installation site and application conditions a small amount of condensate may form inside the blowback air
pressure vessel. Open the drain screw at the bottom of the vessel and drain the condensate at least once a year.
If the probe needs to be serviced more frequently due to operating conditions, we recommend also draining the condensate at
these intervals.
CAUTION High pressure
Pressure vessel under pressure.
Before opening the condensate drain, close the air supply to the blowback control and
drain the vessel by manual blowback.
Pressing the main switch for the blowback control to interrupt the voltage supply.
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GAS 222.31 Ex2
6.2 Backwashing the Intake Filter (within the process stream)
DANGER Adiabatic compression during gas blowback (explosion hazard)!
Adiabatic compression may cause high gas temperatures and must be checked by the
user.
Gas blowback may result in high gas temperatures due to adiabatic compression. This
can cause flammable gases to ignite spontaneously.
a) Blowback of explosive atmosphere / gases is prohibited.
b) Flammable atmosphere / gases (non-explosive) may only be blown back with nitro-
gen (inert gas).
Be sure to use filtered air with a minimum rating of PNEUROP / ISO Class 4 for blowback:
Class Particles / m3
Particle size:
(1 to 5) µm
Pressure dew point
[°C]
Residual oil content
[mg / m3]
4to 1000
(no particles ≥ 15 µm)
≤ 3 ≤ 5
6.2.1 Manual Blowback (Without Blowback Control)
The shut-off valve in the air supply (inert gas supply) to the pressure vessel must be open. The optional pressure gauge on the
pressure vessel shows the current operating pressure.
– To blowback, first close the shut-off valve in the gas probe (handle below the probe/weather hood).
– Then abruptly open the ball valve inside the connecting line from the pressure vessel to the probe until the display on the
pressure gauge has dropped to the lowest reading.
– After blowback, close the ball valve and open the shut-off valve in the probe.
6.2.2 Automatic Blowback (External Blowback Control)
For automatic blowback, the shut-off valve in the probe with must have a pneumatic control (optional). The control unit for the
system is designed for sequential valve control, i.e.:
1. Close the shut-off valve in the probe using the pneumatic control.
2. Open the solenoid valve between the pressure vessel and probe for approx. 10 seconds.
3. Open the shut-off valve in the probe.
Blowback can also be set as a closed process at intervals ranging from several minutes to hours or even days based on require-
ments.
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GAS 222.31 Ex2
6.3 Maintenance Schedule
NOTICE
When using the probe in explosive areas the maintenance schedule must be observed!
Maintenance schedule for normal ambient conditions:
Component Interval in operating
hours
Work to be performed To be performed by
Entire probe every 8000 h – Check gas connections
– Check safety devices and controllers
– Check electrical protective measures
– Working properly, dirt, visual inspection for dirt/
damage.
If damaged, replace or have repaired by Bühler.
Operator
Ball valves every 8000 h – Check ball valve function and check for leaks. Operator
Filter every 8,000 h – Check dirt level of filter. Operator
Seals every 8,000 h – Replace O-rings.
– Replace seals after every filter change.
Operator
Pressure vessel every 8,000 h – Drain condensate Operator
Drive 1 x per year – Replace seals, guides and lubricants. Manufacturer
Entire probe
With respect to ball valve,
pneumatic and solenoid
valves
after 20,000 h or
3years
– Inspection by Bühler Service technician /
Bühler
Limit switch after 5 years – Replace seals on the shaft and the housing cover. Operator
18 Bühler Technologies GmbH BE460052 ◦ 03/2022