Equipment Unit and Component Code
Reference List
(Edition 1990)
all terms sorted alphabetically
Description Equipment
unit key
Component key
Absolute dose measuring circuits CX
Absolute pressure measuring circuits CP
Absorbed doserate measuring circuits CX
Absorber assemblies JA
Absorber assemblies, burnable JE
Absorber vessels AT KT
Absorbers AT KT
Absorbers (for cooling) AC KC
Absorbers (for separating materials) AT
Absorption refrigerators AH
Absorptive filters AT KT
Absorptive silencers BS
Acceleration measuring circuits CS
Accumulators BB KD
Acoustic enclosures (dedicated removable unit) BU
Acoustic signaling devices - H
Acoustic transducers - B
Active filters (electrical) - Z
Activity measuring circuits CR
Actuating equipment (non electrical) AS
Actuating equipment for electrical variables GX
Actuators (electrical, oscillatory) - Y
Actuators (electrical, rotary) - M
Actuators (non- electrical, rotary) MM
Actuators (non electrical, oscillatory) MS
Adjustable foundations BF MF
Adjustable orifices KA
Adjustable resistors (electrical) - R
Adjusting equipment, not for electrical variables AS
Adjusting valves AA KA
Admittance, conductance, susceptance measuring circuits CE
Aerials - W
Agitators KM
Air- conditioning units AH
Air blowers (for compressing purposes) AN KN
Air blowers (for conveying purposes) AF KF
Air classifiers (physical separator) AT KT
Air ejectors BN
Air engines MM
Air filters KT
Air heaters AC KC
Air inlet valves AA KA
Air lift tanks BB KD
Air pressure (atmospheric) measuring circuits CP
Air pumps AN KN
Air soot blowers (for cleaning purposes) AT KT
Air turbines MT
Air- vane relays - F
Airlocks AB
Alarm annunciation equipment - H
Alarm devices (non- electrical) QH
Amplifier valves - V
Analog comparators - N
Analog computers - N
Analog controllers - N
Analog input/output devices - N
Analog signal conditioning equipment for computers (EM- EQ available) EM Analog signal conditioning equipment for computers (EM- EQ available) EN Analog signal conditioning equipment for computers (EM- EQ available) EP Analog signal conditioning equipment for computers (EM- EQ available) EQ Analog signal conditioning equipment for controls (EA- EE available) EA Analog signal conditioning equipment for controls (EA- EE available) EB Analog signal conditioning equipment for controls (EA- EE available) EC Analog signal conditioning equipment for controls (EA- EE available) ED Analog signal conditioning equipment for controls (EA- EE available) EE Analog signal conditioning equipment for protection (EW- EZ available) EW Analog signal conditioning equipment for protection (EW- EZ available) EX Analog signal conditioning equipment for protection (EW- EZ available) EY Analog signal conditioning equipment for protection (EW- EZ available) EZ Analog signal conditioning equipment for reactor protection ER Analog signal conditioning equipment for signaling (EG- EK available) EG Analog signal conditioning equipment for signaling (EG- EK available) EH Analog signal conditioning equipment for signaling (EG- EK available) EJ Analog signal conditioning equipment for signaling (EG- EK available) EK Analog signal conditioning equipment, combined EU
Analog timers (integr., diff., delay) - N
Analog- to- digital converters (frequency, voltage, current) - U Analog, binary & digital indication & recording measuring instruments - P Analytical control circuits, except DD, DM, DV DQ
Analytical measuring circuits, except CD, CM, CV CQ Analytical measuring circuits, indirect, except FD, FM, FV FQ
Analytical measuring instruments (non- electrical) QP
Analytical sensors (electrical) - B
Analytical transducers - B
Angle measuring circuits CG
Angle transducers - B
Angular velocity measuring circuits CS
Antennae - W
Apron conveyor belts AF
Apron conveyors KF
Arcing chambers - F
Area measuring circuits CG
Articulated shafts MU
Assemblies of equipment (electrical) - A
Asynchronous motors - M
Attachments - see supports
Automatic cut outs - F
Automatic drains traps AA KA
Auxiliary contractors - K
Auxiliary relays - K
Axial- flow blowers AN KN
Axial- flow compressors AN KN
Axial- flow fans AN KN
Backup burners AV KV
Baffle separators KT
Baffles (flow guides) MR
Balancing equipment (electrical) - Z Balancing machines AW KW Balers (packaging) KK Ball mills AJ KJ Ball valves AA KA Band brakes MB Band clutches MK Band filters AT KT Bar screens AT KT Barometers QP Barriers AB KB Base supports BQ Basins KD Batteries - G Batteries GR
Battery condition sensors - B
Battery racks GZ
Bearing assemblies (for main and heavy machinery) HD
Beater mills AJ KJ
Beater wheel mills AJ KJ
Bellows expansion joints (for piping) MR
Bells - H
Belt cleaning equipment AT KT
Belt conveyors AF KF
Belt drives MU
Bending machines AW KW
Bending moment measuring circuits CW
Bifurcated terminals - Z
Bifurcated transformers - Z
Bimetallic trips - F
Binary elements - D
Binary status indicators - P
Bistables - B
Blank flanges KA
Blanks KA
Blinds AB KB
Block and tackle (permanently installed) AE KE
Blockers - D
Blower units AN
Blowers AN
Boiler circulation pumps AP KP
Boiler drums BB
Boiling point measuring circuits CQ
Bolted couplings MK
Brake motors - M
Brake operators (magnetic) - Y
Brake resistors - R Brake units AU Brakes MB Braking equipment AU Breakers AJ KJ Breeder assemblies JC Bridge cranes AE Bridge rectifiers - V
Broaching machines (machine tools) AW KW
Buchholz relays - F Bucket conveyors AF KF Bucket elevators AF KF Buckets KF Buffer amplifiers - N Built- in equipment - S
Built- in heaters (electrical) - E
Built- in heaters (non- electrical) KC
Bulkhead walls KB
Bulkheads AB
Burglar alarm boxes - H
Burners KV
Busbars (electrical) - W
Buses - W
Butterfly valves AA KA
Buzzers - H
Cabinet- mounted switchgear (electrical) - Q
Cabinet power supply equipment GW
Cable penetrations (GA- GG for us as required) GA Cable penetrations (GA- GG for us as required) GB Cable penetrations (GA- GG for us as required) GC Cable penetrations (GA- GG for us as required) GD Cable penetrations (GA- GG for us as required) GE Cable penetrations (GA- GG for us as required) GF Cable penetrations (GA- GG for us as required) GG
Cable plugs - X
Cable racks GZ
Cable simulation networks - Z
Cable terminations - Z
Cables - W
Calcinating kilns AW
Calculation equipment (root- extraction, multiplication, division) - N Calorific value measuring circuits (HHV) CQ
Calorific value measuring circuits (LHV) CQ
Capacitance measuring circuits CE
Capacitors - C
Cartridge filters KT
Cartridge- type heaters - E
Cascade coolers AC KC
Casting machines AW KW
Catalytic converters KT
Cathode ray tubes - V
Centrifugal clutches MK
Centrifugal compressors (axial and radial flow) AN KN
Centrifugal fans (axial and radial flow) AN KN
Centrifugal pumps (axial, mixed- flow and radial flow) AP KP
Centrifugal switches (electrical) - F
Centrifuges AT KT Chain conveyors AF KF Chain drives MU Changing equipment AE Channel sections MR Channels BR Chargers GU Chillers AH
Chimes - H
Chokes - L
Chutes MR
Chutes (as gullies) BR
Chutes (for conveying) KF
Circular conveyors AF KF Circulation pumps AP KP Clarifiers AT Classifiers AT KT Claw clutches MK Cleaning equipment AT Cleaning machines KT Clock generators - D
Clock pulse generators - G
Clocks (electrical) - P
Clocks (non- electrical) QP
Closures AB Clutch units AU Clutches MK Coal mills AJ KJ Coaxial cables - W Coaxial plugs - X Cocks KA Code converters - U
Code- operated switches - S
Coding equipment - U
Coil spring couplings MK
Coils - L
Cold air refrigerators - see refrigerators
Cold junction compensators (electrical) - P
Combined variables control circuits DU
Combined variables measuring circuits, direct CU Combined variables measuring circuits, indirect FU
Combustion equipment AV KV
Command output devices - D
Compacting equipment, only if part of process AK
Compacting machines (packaging) KK
Comparators (electrical) - D
Compressed air engines MM
Compressed air valves AA KA
Compression refrigerators AH
Compressor units AN
Compressor units AN
Compressors AN KN
Computers - N
Concentration measuring circuits CQ
Concentration transducers (electrical) - B
Concrete Foundations BF MF Concrete pipes BR MR Concrete vessels BB KD Condensation chambers KD Condensers AC KC Conductivity converters - B
Conductivity measuring circuits CQ
Conductivity meters - B
Contact- making pressure gauges (electrical) - P Contact- making pressure gauges (non- electrical) QP
Contact- making thermometers (electrical) - P
Contact- making thermometers (electrical) QP
Contactors (electrical) - K
Contactors (non- electrical switches) KB
Continuous conveyors AF KF
Control rod - see absorber assembly
Control switches - S
Control valve operators (electrical) - Y
Control valves AA KA
Control valves (for instruments) AA KA
Controllers (electrical) - N
Controllers (non- electrical) QN
Convectors KC
Converter equipment (electrical) GU
Converters (non- electrical) AU
Converters (non- electrical), other than MG and MK MU Converters from electrical to other electrical variables - U Converters from non- electrical to electrical variables and vice versa - B
Converters, rotary GU Conveyor belts AF KF Conveyor equipment AF Conveyors AF KF Coolers KC Cooling equipment AH
Cooling towers (as part of a function) AC
Cooling units AH
Core memories - D
Correcting elements for measured variables - D
Correction capacitors - C
Counter tubes - B
Counters (electrical) - P
Counters (non- electrical) QP
Counting mechanisms QP
Coupling capacitors - C
Coupling elements - S
Coupling units AU
Couplings, clutches MK
Couplings, clutches (as valves) AA KA
Covers AB KB Crane bridges AE Crane hoists AE Crane rails BQ Crane trolleys AE Cranes AE
Criteria indication devices - D
Crossbar distributors - X
Crossbeams BQ
Crushers KJ
Crushing equipment, only if part of a process AJ
Crushing machines KJ
Crystal filters (electrical) - Z
Crystal transducers - B
Current limiting coils - L Current measuring circuits (apparent, active, reactive), electrical CE
Current- operated earth- leakage circuit breakers - F
Current transformers - T
Cutting equipment (part of process) AJ
Cutting machines AW KW
Cyclones AT
Damboards KB
Dampers KA
Damping elements (mechanical) MU
Damping equipment (electrical) - Z
Damping equipment (mechanical) BQ
Damping resistors (electrical) - R
Dams AB KB
Data input/output equipment for automation systems GK Data input/output equipment for process computers GK
Datum reservoirs (in measuring circuits) QS
DC converters - G DC current transformers - U DC current/voltage transformers - U DC generating equipment GR DC motors - M DC voltage transformers - U Decade switches - S Decanters AT KT Decoders - U Decoding equipment - U Dehumidifiers AT KT
Delay devices (electrical) - D
Delay lines - D
Demineralizers (chemical dryers) AT KT
Demineralizers (filters) AT KT
Demodulators - U
Density control circuits DD
Density measuring circuits, direct CD
Density measuring circuits, indirect FD
Density measuring instruments (non- electrical) QP
Density sensors (electrical) - B
Density transducers (electrical) - B
Desorber columns AT KT
Desuperheaters KC
Devices for alarm signaling - H
Devices for analog data storage - N
Devices for limit monitoring - F
Devices for protection - F
Devices for reactor protection - F
Devices for time signaling - H
Dials - S
Diaphragm check valves AA KA
Diaphragm compressors AN KN
Diaphragm gate valves AA KA
Diaphragm isolation valves AA KA
Diaphragm pressure sensors QB
Diaphragm pumps AP KP
Diaphragms QB
Differential pressure transducers - B
Differentiating filters - Z
Differentiators - N
Diffusers BS
Digital computer- based controllers - D
Digital computers - D
Digital controllers - D
Digital equipment - D
Digital pulse shapers - D
Digital- to- analog converters - U
Diode matrix - D
Diodes - V
Dipoles - W
Direct contact heat exchangers AC KC
Directional joints for hollow waveguides (electrical) - W
Dirt traps AT KT
Disc brakes MB
Discharge equipment AF
Disconnect plugs - X
Disconnect sockets - X
Disconnecting links (electrical) - Q
Discrepancy switches - S
Discriminators - U
Disk memories - D
Distance control circuits DG
Distance measuring circuits, direct CG
Distance measuring circuits, indirect FG
Distance measuring instruments (non- electrical) QP
Distance sensors (electrical) - B
Distance transducers - B
Distillers AT
DNB margin measuring circuits CQ
Document readers - D
Doors AB KB
Dose meter reading devices QP
Dose meters QB
Dosing equipment AF
Dosing pumps AP KP
Dotted- line recorders AP KP
Double pipe heat exchangers AC KC
Double- screw pumps AP KP
Downcomers MR
Drains traps AT KT
Drilling machines AW KW
Driving gear AE KE
Drop- annunciator relays - H
Drop- indicator relays - H
Drum brakes MB
Drum controllers - Q
Drum kilns AV KV
Drum memories (electrical) - D
Drum mills AJ KJ
Dryers KT
Drying equipment AT
Ducts MR
Ductwork BR
Ductwork components MR
Duplicating equipment (electrical) BR
Dust collectors AT
Dynamometers - B
Earth fault measuring circuits CE
Earth sounders (level measurement) - B
Earthing bars - W
Earthing disconnectors - Q
Earthing equipment GV
Earthing jumpers - X
Earthing switches - Q
Eddy current brakes, operators - Y
Eddy current braking equipment AU
Edging tools AW KW
Electric arc welding machines, stationary AW
Electric hoists AE
Electric motor actuators - Y
Electric motors - M
Electrical adjusters, not electric motors - Y
Electrical and I & C assemblies (black box) GH
Electrical filters - Z
Electrical power measuring circuits (apparent, active, reactive) CE
Electrical variables control circuits DE
Electrical variables measuring circuits, direct CE Electrical variables measuring circuits, indirect FE Electrical work measuring circuits (apparent, active, reactive) CE
Electro- hydraulic actuators - Y
Electromagnetic filters AT
Electromagnetic pumps AP
Electromagnetic separators AT
Electromagnetical operated clutch units AU
Electromagnetical operated clutches, coupling parts MK Electromagnetical operated clutches, driving parts - Y
Electromagnets - Y
Electromechanical controllers - N
Electromechanical level measuring circuits CL
Electron tubes - V
Electron valves - V
Electronic and electromechanical controllers - N
Electronic cards - A
Electronic controllers (continuous and discontinuous action) - N
Electronic modules - A
Electronic signal monitoring equipment - F
Electronic switches - S
Electropneumatic actuators - Y
Electrostatic precipitators AT KT
Enclosures BU
Engines (non- electrical) MM
Entalphy measuring circuits CU
Entropy measuring circuits CU
Equalizers (electrical) CU
Ermeto pipe connectors MR
Escalators AF
Excursion recorders - H
Expansion control circuits DY
Expansion measuring circuits, direct CY
Expansion measuring circuits, indirect FY
Expansion measuring instruments (non- electrical) QP
Expansion sensors (electrical) - B
Expansion sensors (mechanical) QB
External shoe brakes MB
Extractor units AT
Extractor vessels AT
Extractors (part of air ejector) BN
Extractors (with separate drive) AT
Extreme value selectors - N
Extruders AF KF
Fan units AN
Fans KN
Fault recorders - P
Fault value recorders - P
Feed heater safety equipment AA KA
Feed heaters AC KC
Feeders AF KF
Field circuit breakers (electrical) - Q
Field discharge resistors (electrical) - R
Field strength measuring circuits (electrical) CE
Filter changing equipment AW KW
Filter elements KT
Filter presses (pressure filtration) AT
Filter vessels KD
Filtering equipment AT
Filters (electrical) - Z
Filters (non- electrical) KT
Finned spray coolers AC KC
Fire alarms - B
Fire alarms - H
Fire breaks AB KB
Fire dampers AA KA
Fire extinguishers as equipment units BB
Fire- fighting valves AA KA
Fire- hose cabinets BU
Fire hydrants AA
Firing equipment AV
Fittings MR
Fixed resistors (electrical) - R
Flag indicators - H
Flags - H
Flame cutting machines AW KW
Flame detectors - F
Flange couplings MK
Flanged face clutches MK
Flanges MR
Flash tank vessels, other than QS KD
Flash tanks BB KD
Flasher relays - K
Flexible couplings MK
Flocculators AT
Floor gratings BQ
Floor supports MU
Flow control circuits DF
Flow controllers (electrical) - B
Flow controllers (non- electrical) QN
Flow diverters MR
Flow indicators (sight glasses) QP
Flow limiters KA
Flow limiters (as valves) AA KA
Flow limiters (not valves) BP
Flow measuring circuits, direct CF
Flow measuring circuits, indirect FF
Flow metering equipment (non- electrical) QP
Flow meters (non- electrical) QP
Flow meters, inductive - B
Flow meters, ultrasonic - B
Flow monitors - F
Flow nozzles QP
Flow restrictor assemblies (nucl.) JD
Flow restrictor nozzles BP KA
Flow restrictors (non- electrical) QB
Flow restrictors (not metering orifices) BP
Flow restrictors (nucl.) JD
Flow restrictors, as instrumentation (non- electrical) JD
Flow sensors (electrical) - B
Flow sensors (non- electrical) QB
Flow transducers - B
Flue gas catalytic converter modules BT
Fluid couplings MK
Fluid gears MG
Flyball governors QN
Folding doors AB KB
Force measuring circuits CW
Forging hammers KW
Forging machines AW KW
Fouling measuring instruments (non- electrical) QP
Foundations BF MF
Fractionating columns AT
Freewheeling clutches MK
Frequency changers - N
Frequency control circuits DS
Frequency current converters - U
Frequency demodulators - U
Frequency departure meters - Z
Frequency measuring circuits, direct CS
Frequency measuring circuits, indirect FS
Frequency measuring instruments - P
Frequency meters - P
Frequency modulators - U
Frequency scalers - D
Frequency sensors (electrical) - B
Frequency transformers - U
Frequency voltage converters - U
Friction clutches MK
Fume extractors AN KN
Function fuses - F
Function generators - N
Function keys - S
Functional group control devices - D
Functional group monitoring devices - P
Fuse boxes - F
Fuse disconnectors - Q
Fused load- break switches - Q
Fuses - F
Gas analyzers QP
Gas burners AV KV
Gas circulators AN KN
Gas cylinder valves AA KA
Gas cylinders KD
Gas discharge tubes - V
Gas engines MM
Gas injection equipment AM
Gas pilot burners AV KV
Gas scrubbers AT KT
Gas stripper columns KT
Gas strippers KT Gas turbines MT Gas valves KA Gates KB Gating elements - D Gear pumps AP KP Gearbox units AU Gearboxes MG Generator units AG Generators - G Globe valves KA
Granulating equipment (for size reduction) AJ
Granulating equipment (for treatment) AW
Graph calculators - N
Grates KV
Grates (classifying) KT
Grates (combustion equipment) AV KV
Grid- spring couplings MK
Grinding machines AW KW
Gripping or lifting gear KE
Group control devices - D
Guard pipes, other than QT MR
Gullies KD
Gullies BR
Hall- effect generators - B
Hall- effect probes - B
Hammer crushers AJ KJ
Handling equipment, stationary AW
Handling equipment, stationary for maintenance KW
Hangers BQ MU
Hannemann governors QN
Hatch gates AB KB
Headers BB
Heat exchangers KC
Heat flux measuring circuits CU
Heat rate measuring circuits CU
Heat treatment furnaces AW KW
Heater coils - E
Heater rods - E
Heaters AH
Heaters - see once- trough heaters or feed heaters
Heating blankets (electrical) - E
Heating boilers AH
Heating elements (electrical) - E
Heating elements (non- electrical) KC
Heating equipment AH
Heating strips - see trace heaters
Heating system circulation pumps AP KP
Heating units AH
Heating wires - E
Helical compressors AN KN
High- speed circuit- breakers - Q
High, low and band- pass filters - Z
Hinged gates AB KB
Hoisting gear AE KE
Hoisting mechanisms AE KE
Hollow waveguides (electrical) - W
Hoods BU
Hoppers BB
Horns - H
Hose connectors MR
Hoses BR
Hot- water boilers AH
Hours- run meters - P
Humidifiers AH
Humidity control circuits DM
Humidity converters (electrical) - B
Humidity measuring circuits, direct CM
Humidity measuring circuits, indirect FM
Humidity measuring instruments (non- electrical) QP
Humidity monitory (electrical) - F
Humidity sensors (electrical) - B
Humidity transducers - B
HV asynchronous motors with squirrel- cage rotor - M
HV circuit breakers - Q HV disconnectors - Q HV switch- disconnectors - Q HV switches - Q HV synchronous motors - M HVHRC fuses - F Hydrants AA Hydraulic couplings MK Hydraulic motors MM Hydraulic turbines MT Igniters - E
Illuminance measuring circuits CR
Illuminated momentary contact push buttons - S
Illuminated switches - S
Indexing mechanisms MG
Indicators (electrical) - P
Indicators (non- electrical) QP
Individual control devices - D
Individual printed circuit boards - D
Inductance- capacitance filters - Z
Inductance measuring circuits CE
Inductances - L
Inductive potentiometers - B
Infrared devices - B
Initiators - B
Injectors BN
Inlets (piping components) MR
Input devices for measured variables - B
Input devices, analog - N
Input devices, binary - D
Inside shoe brakes MB
Inside wall linings - see insulation
Inspection glasses (flow, level) QP
Instrument isolation valves KA
Instrument lines QR
Instrument racks BQ
Insulation BU
Insulators (electrical) - F
Integrator - N
Interface layer control circuits DL
Interface layer measuring circuits, direct CL Interface layer measuring circuits, indirect FL
Interface modules - D
Interference and spark suppression equipment (electrical) - Z
Interlocks, mechanical MB
Inverse- time and definite- time overcurrent releases - F
Inverters - G Inverters (electrical) - U Inverting amplifiers - N Ion exchangers AT KT Ionization chambers - B Isolation dampers AA KA
Isolation gate valves AA KA
Isolation globe valves AA KA
Isolation valve assemblies AA
Jack plugs - X
Jet cleaning equipment AT KT
Jet ejectors BN
Jet pumps AP KP
Jumper wires - W
Junction boxes (electrical), GA- GG available GA Junction boxes (electrical), GA- GG available GB Junction boxes (electrical), GA- GG available GC Junction boxes (electrical), GA- GG available GD Junction boxes (electrical), GA- GG available GE Junction boxes (electrical), GA- GG available GF Junction boxes (electrical), GA- GG available GG Junction boxes for light- current- systems of national telecommunications GM Junction boxes for light- current systems, other than GM GY
Junction boxes for lighting GP
Keyboards - S
Keyless compression couplings MK
Lamp poles BQ
Lasers - A
Lathes AW KW
Length control circuits DG
Length measuring circuits, direct CG
Length measuring circuits, indirect FG
Length measuring instruments (non- electrical) QP
Length sensors (electrical) - B
Length transducers - B
Level control circuits DL
Level gauges (magnetic) QP
Level indicators (non- electrical) QP
Level measuring circuits, direct CL
Level measuring circuits, direct CL
Level measuring circuits, indirect FL
Level monitors - F
Level transducers - B
Lift check valves AA KA
Lift check valves, damped AA KA
Lifting platforms AE
Light fittings - E
Light fittings complete with lamps - E
Light switches - Q
Lighting equipment - E
Lightning protection equipment GV
Limit switches - S
Limiters (electrical) - Z
Line monitors - F
Liners BS
Linings - see insulation
Link conveyors AF KF
Linkages MU
Liquid crystal displays - P
Liquid level control circuits DL
Liquid level controllers (non- electrical) QN
Liquid level measuring circuits, direct CL
Liquid level measuring circuits, indirect FL
Liquid level measuring instruments (non- electrical) QP
Liquid ring compressors AN KN
Liquid ring pumps AP KP
Liquid starters (starting resistor electrical) - R
Load cells (electrical) - B
Load cells (non- electrical) QB
Local control stations - A
Lock out coils - Y
Logic elements (electrical) - D
Logic testing equipment - P
Loudspeakers - H
Louver dampers AA KA
Low voltage circuit- breakers - Q
Low voltage disconnectors - Q
Low voltage switch- disconnectors - Q
Machine casing parts (for main and heavy machinery) HA
Machine foundations MF
Machine rotating parts (for main and heavy machinery) HB
Machine tools AW KW
Machine tools, stationary AW
Machine tools, stationary for maintenance KW
Magnetic drums KT
Magnetic field transducers - B
Magnetic filters - see electromagnetic filters
Magnetic particle clutches MK
Magnetic tape memories - D
Magnetic tape units - D
Magnetoresistive potentiometer - B
Main grates AV KV
Maintained- contact rotary control switches - S
Manipulators AE
Manual input measuring circuits, direct (manually- operated sensors) CH
Marshaling racks - X
Masers - A
Mass control circuits DW
Mass flow control circuits DF
Mass flow density measuring circuits CF
Mass flow limiters KA
Mass flow limiters (as valves) AA KA
Mass flow limiters (not valves) BP
Mass flow measuring circuits CF
Mass flow measuring circuits, direct CF
Mass flow measuring circuits, indirect FF
Mass flow sensors (non- electrical) QB
Mass measuring circuits, direct CW
Mass measuring circuits, indirect FW
Mass measuring instruments QP
Material property control circuits, other than DD, DM, DV DQ Material property measuring circuits, direct, other than CD, CM, CV CQ Material property measuring circuits, indirect, other than FD, FM, FV FQ
Measuring circuit isolation valves KA
Measuring circuits for combined valves CU
Measuring instruments (electrical) - P
Measuring instruments (non- electrical) QP
Mechanical power measuring circuits (electrical power = CE) CU Mechanical work measuring circuits (electrical work = CE) CU
Melting furnaces AW KW
Memories (electrical) - D
Memory devices (electrical) - D
Memory devices (mechanical) BB
Mercury arc rectifiers - V
Metal- to- metal clutches MK
Metallic grid flexible couplings MK
Metering equipment AF Metering orifices QB Metering pumps AP KP Meters - P Micro fuses - F Microphones - B Milling machines AW KW
Mills AJ KJ
Miniature circuit breakers - F
Miniaturized control equipment - S
Mixers KM Mixing units AM Modems - U Moderator assemblies JM Modulating valves AA KA Modulators - U
Momentary- contact limit switches - S
Momentary- contact push buttons - S
Momentary- contact relays - K
Momentary- contact rocker switches - S
Momentary- contact rotary control switches - S
Momentary- contact switch assemblies - S
Momentary- contact tumbler switches - S
Monitoring devices (electrical) - D
Monitoring equipment for plant maintenance AX
Monitoring modules (electrical) - A
Monitors - F
Monitors - P
Monostable elements - D
Motor control centers GS
Motor generators - G
Motor protection switches - Q
Motor terminal boxes - X
Motorized potentiometers - R
Motors (electrical) - M
Motors (non- electrical) MM
Mounting racks BQ
Mufflers BS
Multiblade dampers AA KA
Multifuel engines MM
Multiple- disc brakes MB
Multiple plugs - X
Multiplexers - U
Multipoint selector switches - S
Multiport ball valves AA KA
Multiport check valves AA KA
Multiport dampers AA KA
Multiport gate valves AA KA
Multiport globe valves AA KA
Multipurpose valves AA KA
Neutral balancing capacitors - C
Neutral disconnectors - Q
Neutralizing equipment AM KM
Neutron flux control circuits for reactor power DX Neutron flux measuring circuits for reactor power, direct CX Neutron flux measuring circuits for reactor power, indirect FX
Neutron flux transducers - B
Neutron sources JN
Non- linear resistors - R
Nozzles MR
Nozzles - see flow restrictor nozzles or flow nozzles
NTC and PTC thermistors (electrical) - R
Oil separators AT KT
Oil sight glasses QP
Oilers KF
Once- through heaters AH
Open vessels BB KD
Operating counters - P
Operating devices - S
Operating mechanism (freewheeling clutch) MK
Operational amplifiers - N
Operator I/O typewriters - Y
Operator service equipment for process computers GK Operator service equipment for programmable controllers GK
Optical character readers - U
Optical transformers - B
Optical waveguides - W
Opto- isolators - U
Orifice plates QB
Orifices (not metering) BP KA
Oscillators - G Oscillographs - P Oscilloscopes - P Outer sheating BU Outlet amplifiers - D Outlet valves AA KA
Outlets (piping components) MR
Output devices, analog - N
Output devices, binary - D
Outside shoe brakes MB
Overcurrent protective devices - F
Overcurrent releases, magnetic - F
Overcurrent short- circuiting switches - F
Overrunning clutches MK
Overspeed trips - F
Overvoltage protectors (electrical) - F
Packaging equipment, only if part of process AK
Packaging machines KK
Packed clutches MK
Pattern moulding machines AW KW
Pawls MB
Pegging steam safety valves AA KA
Pelletizing equipment AK
Pendulum mills AJ KJ
Penetration assemblies BQ MR
Period (electrical) measuring circuits CE
Peristaltic pumps AP KP
Permanent magnets - Y
Personnel transport equipment AE KE
Petrol engines MM
Petrol traps (physical separation) AT KT
pH converters - B pH measuring circuits CQ pH transducers - B Photocells - B Photoelectric barriers - B Photoelectric cells - B
Photoresistors - B
Pick- ups - B
Piezoelectric transducers - B
Pilot oil burners (incl. Backup burners) AV KV
Pilot pulverized fuel burners AV KV
Pilot valves AA KA Pinch valves KA Pinned couplings MK Pipe bends MR Pipe connectors MR Pipe elbows MR Pipe unions MR Piping BR Piping penetrations BQ Piping products MR Piston compressors AN KN
Planing, slotting machines AW KW
Plate- type heat exchangers AC KC
Platforms BQ Plenum assemblies JG Plotters - Y Plug distributors - X Plug- in cards - A Plugs - X
Pockets (only for sensors protection) QT
Pole changing controls - Q
Polishing machines AW
Polysius screws KF
Position control circuits DG
Position controllers (non- electrical) QN
Position measuring circuits, direct CG
Position measuring circuits, indirect FG
Position measuring instruments (non- electrical) QP
Position monitors - B
Position sensors (electrical) - B
Position sensors (non- electrical) QP
Position transducers - B
Positioner, electrical (not electric motor) - Y
Positioner, non- electrical MS
Positioning drives, electrical (electric motor) - M
Positioning gearboxes MG
Positive- displacement fans AN KN
Potential measuring instruments - B
Potentiometers - R
Power amplifiers - N
Power contractors - K
Power counters - P
Power density measuring circuits (electromagn.) CE Power density measuring circuits (mechan.) CU
Power outlets (electrical) GQ
Power supplies - G
Power supply equipment - G
Power supply modules - G
Power supply units - G
Power switchgear - Q
Precipitation vessels KT
Press tools AW
Presses (packaging) KK
Presses (tools) KW
Pressure cells (electrical) - B
Pressure control circuits DP
Pressure controllers (electrical) - N
Pressure controllers (non- electrical) QN
Pressure gauges QP
Pressure measuring circuits, direct CP
Pressure measuring circuits, indirect FP
Pressure measuring devices (non- electrical) QP
Pressure reducing valves AA KA
Pressure sensors - P
Pressure sensors (electrical) - B
Pressure switches - F
Pressure switches - S
Pressure test closures KA
Pressure- to- pressure converters QB
Pressure transducers (electrical) - B
Pressure vessels BB KD
Pressurizers BB KD
Printed circuit boards (electrical) - A
Printers - Y Programmable controllers - D Programming plugs - X Proportioners KF Proportioning equipment AF Proportioning pumps AP KP Proportioning valves AA KA
Protective equipment (electrical) - F
Protective relays (electrical- magnetical) - F
Proximity switches - B
Pulse counters - D
Pulse generators (electrical) - B
Pulse measuring instruments (non- electrical) QP
Pulse shapers - D
Pulverized fuel burners AV KV
Pump units AP Pumps KP Punches AW KW Push buttons - S Pylons BQ Pyrometers - B
Quality variable control circuits, direct, other than CD, CM, CV CQ Quality variable control circuits, indirect, other than FD, FM, FV FQ Quality variable control circuits, other than DD, DM, DV DQ
Quality variable sensors (electrical) - B
Quartz oscillators - G
Quick- closing check valves AA KA
R/C Filters - Z
Rabbles AM KM
Racks for electrical and I & C equipment GZ
Racks, other than GZ BQ
Radial- flow blowers AN KN
Radial- flow compressors AN KN
Radial- flow fans AN KN
Radiation control circuits DR
Radiation detectors - B
Radiation measuring circuits, direct CR
Radiation measuring circuits, indirect FR
Radiation measuring instruments - B
Radiation monitors - E
Radiation sensors (electrical) - B
Radiation transducers - B
Radiators KC
Radiators as equipment units AH
Radio relay systems, PLS and UHF - W
Radio sets - B
Radio transmitters - E
Railings BQ
Rails BQ
Rapping gear (for separation) AT
Reaction vessels BB KD Receivers (electrical) - E Reciprocating compressors AN KN Reciprocating pumps AP KP Recombiners AT KT Recorders - P Rectifier components - G Rectifiers - V Reducers MR Reduction gearings MG Reed relays - K Reflector assemblies JF
Refrigerating heat exchangers AC KC
Refrigerators AH
Refuse shredders AJ KJ
Registers - D
Regulating ball valves AA KA
Regulating dampers AA KA
Regulating gate valves AA KA
Regulating resistors - R
Regulating valve assemblies AA KA
Reheaters AC KC
Relay modules - D
Relays - K
Releasing controllers AS
Relief valves AA KA
Remote control devices - U
Remote- indicating circuit- breakers - F
Remote manipulators KE
Remote position sensors - B
Resistance devices - R
Resistance heating devices AH
Resistance measuring circuits (apparent, active, reactive) CE
Resistance thermometers - B
Resistance trace heaters (electrical) - E
Resistors (electrical) - R
Rheostatic starters (electrical) - R Rheostats - R Rinsing basins KD Rinsing equipment AT KT Rocker switches - S Roller conveyors AF KF Roller crushers AJ KJ Roller grates AV KV Roller mills AJ KJ
Rolling equipment (machine tools) AW KW
Rolling gates AB KB
Roots blower AN KN
Rope drives MU
Rope winches AE KE
Rotary air heaters AH
Rotary blowers AN KN
Rotary brushes KT
Rotary compressors AN KN
Rotary displacement pumps AP KP
Rotary filters AT KT
Rotary mixers AM KM
Rotary piston blowers AN KN
Rotary piston compressors AN KN
Rotary piston pumps AP KP
Rotary resolvers - H
Rotary thickeners AM KM
Rotary transformers - T
Rotary valve compressors AN KN
Rotary valve pumps AP KP
Rotary vane compressors AN KN
Rotary vane feeders AF KF
Rotating drums - S
RT- type pipe unions MR
Rubber flexible couplings MK
Rupture discs KA
Rupture- type safety equipment AA
Safety check valves AA KA
Safety clutches MK
Safety dampers AA KA
Safety valves AA KA
Sand classifiers KT
Sawing machines (machine tools) AW KW
Scale- link travelling grates AV KV
Scraper chain conveyors AF KF
Scraper conveyors AF
Scrapers KT
Screening machines AT
Screens KT
Screens (for cleaning) KT
Screw compressors AN KN Screw conveyors AF KF Screw- in fuses - F Screw pumps AP KP Scrubber towers AT KT Scrubbers AT KT
Selector switches - S
Selectors (electrical) - S
Semiconductors - V
Sensors (electrical) - B
Sensors (non- electrical) QB
Sensors (only if not structurally integral with QP) QB
Separating equipment AT KT Separating machines AT KT Separator valves AA KA Separators AT KT Sequence annunciators - H Sequencers - D
Servo- mechanism (non- electrical), other than MG and MK MU
Servo- mechanism equipment AU
Setpoint adjusters - N
Settering orifices QB
Settling ponds BB KD
Settling tanks AT KD
Shafts (for erection and maintenance only) BE
Shakers KT
Shaking equipment AT
Shaping machines (machine tools) AW KW
Shear blades (machine tools) AW KW
Shear bolt couplings MK
Sheating BU
Shielding - see insulation
Shielding equipment, nuclear JS
Shift registers (eletrot.) - D
Shock absorbers BQ
Shoe brakes MB
Short- circuiting equipment (electrical) - F
Showers AT
Shunt resistors - R
Shunts - R
Sight glasses QP
Signal blockers - D
Signal conditioning for computers (EM- EQ available) EM Signal conditioning for computers (EM- EQ available) EN Signal conditioning for computers (EM- EQ available) EP Signal conditioning for computers (EM- EQ available) EQ Signal conditioning for controls (EA- EE available) EA Signal conditioning for controls (EA- EE available) EB Signal conditioning for controls (EA- EE available) EC Signal conditioning for controls (EA- EE available) ED Signal conditioning for controls (EA- EE available) EE Signal conditioning for protection (EW- EZ available) EW Signal conditioning for protection (EW- EZ available) EX Signal conditioning for protection (EW- EZ available) EY Signal conditioning for protection (EW- EZ available) EZ Signal conditioning for reactor protection ER Signal conditioning for signaling (EG- EK available) EG Signal conditioning for signaling (EG- EK available) EH Signal conditioning for signaling (EG- EK available) EJ Signal conditioning for signaling (EG- EK available) EK
Signal conditioning, combined EU
Signal devices (electrical) - H
Signal fuses - F
Signal isolators - U
Signaling equipment (electrical) - H
Signaling equipment (non- electrical) QH
Signaling lamps - H Signaling modules - H Silencers BS Simulators - P Siphon loops MR Sira valves AA KA Sirens - H Slat conveyors KF Sleeve couplings MK Slewing crushers AJ KJ Slewing gates AB KB Slewing mechanisms AE KE Sliding gates AB KB Smoke detectors QH Smoothing chokes - L Snubbers BQ Socket outlets - X
Sockets (power outlets, electrical) - X
Solder tag blocks - X
Solenoid actuators - Y
Solenoid locking actuators - Y
Solenoid valves AA
Solenoids - Y
Solid waste balers AK KK
Soot- blowers AT KT
Sound pressure measuring circuits CP
Special assemblies (nuclear) JZ
Special components (electrical) - E
Specific gravity measuring circuits CD
Specific volume measuring circuits CD
Spectrometers - B
Speed control circuits DS
Speed governors (non- electrical) QN
Speed measuring circuits, direct CS
Speed measuring circuits, indirect FS
Speed measuring devices (non- electrical) QP
Speed measuring instruments (non- electrical) QP
Speed sensors (electrical) - B
Speed transducers (electrical) - B
Spherical cap luminous annunciators - H
Spray attemporators AC KC
Spray- coating equipment AW KW
Spray equipment AT
Spring clutches MK
Sprinkling equipment (for aerating/deaerating) AT
Sprinkling equipment (for cooling) AC
Sprinkling equipment (for separation) AT
Stairways BQ
Standard volume measuring circuits CD
Starter motors (electrical) - M
Starters - D
Starters (electrical) - R
Starting engines (non- electrical) MM
Static converters - G
Static inverters - G
Stationary grates KV
Steam conditioning valves AA KA
Steam drums AT KD
Steam engines MM
Steam generators AC KC
Steam jet refrigerators AH
Steam- operated air ejectors BN
Steam- operated jet pumps KP
Steam rate, special measuring circuits CU
Steam soot- blowers AT
Steam turbines MT
Steam valves AA KA
Steel pylons BQ
Steel spring clutches MK
Stirring equipment AM
Stirring units AM
Stopcocks AA KA
Storage and memory functions - D
Storage tanks BB KD
Stork spargers KT
Strain gauge cells - B
Strain gauges - B
Strain transducers - B
Strength measuring circuits CU
Strippers AT KT
Structural supports for electrical and I & C equipment GZ
Structural supports, other than GZ BQ
Subassemblies - A
Subassemblies (not assignable to another letter) - A
Subassemblies for high- voltage switchgear - A
Subassemblies for instrumentation and control - A
Subassemblies for low- voltage switchgear - A
Submersible pumps AP
Sunken gates AB KB
Superheaters AC KC
Support frames BQ
Supports for electrical and I & C equipment GZ
Supports, other than GZ BQ
Surface heat exchangers AC KC
Surge arrester systems GV
Surge arresters - F
Surge conductors - F
Surge diverters - F
Surge protective devices - F
Surge short- circuiters - F
Surge tanks (in measuring circuits) QS
Surge tanks (system engineering) KD
Swing check valves AA KA
Swing check valves, damped AA KA
Switches, electrical - S Switchgear equipment (if not identified under procedure equipment) GS
Switchgear trucks GS - A
Switchgear, automatic GS
Synchro- generators (electrical) - B
Synchronization monitoring devices - F
Synchronous motors - M
Tachometer generators - B
Tachometers (electrical) - B
Tanks KD
Tap changers for transformers - Q
Tape punches AW Telecommunication cables - W Telegraphic translators - U Telemeters - P Telephone sets - B Telephones - B
Temperature control circuits DT
Temperature controllers (non- electrical) QN
Temperature measuring circuits, direct CT
Temperature measuring circuits, indirect FT
Temperature measuring instruments (non- electrical) QP
Temperature monitors - F
Temperature sensors (electrical) - B
Temperature sensors (non- electrical) QP
Temperature transducers (electrical) - B
Tensioning equipment, not for electrical control variables AS
Terminal blocks - X
Terminals - X
Terminations (electrical) - Z
Test adapters - P
Test equipment (electrical) - P
Test equipment (non- electrical) QP
Test equipment for plant maintenance AX
Test fittings - P Test jacks - X Test plugs - X Testing fixtures AX QP Testing machines AX Thermal insulation BU
Thermal power measuring circuits CU
Thermal quantity measuring circuits CU
Thermal/cutting machine tools AW
Thermocouples - B
Thermoelectric cells - B
Thermoelectric sensors - B
Thermometers (non- electrical) QP
Thermostats - B
Thermowells (only for sensor protection) QT
Thickeners AT
Thickening evaporators AT
Thin- film evaporators for separating media AT
Throttling valves AA KA
Through conveyors AF KF
Thyristor controllers - G
Thyristors - V
Time control circuits DK
Time- delay relays - K
Time measuring circuits, direct CK
Time measuring circuits, indirect FK
Time measuring instruments (non- electrical) QP
Time monitors - D Time transducers - B Timers - D Timing accessories - D Timing relays - K Tipping equipment AE Tooling, stationary AW KW Toothed couplings MK
Torque measuring circuits CW
Trace heating equipment AH
Transducers - B
Transductors - N
Transformer circulation pumps AP KP
Transformer equipment GT
Transformer load devices - Q
Transformers - T
Transistors - V
Transmission gear (non- electrical), other than MG, MK MU
Transmission paths (electrical) - W
Transmission shafts (non- electrical) MU
Transport gear AE KE
Travelling grates AV KV
Triacs - V
Trigger equipment - N
Trips, magnetic - F
Trolleys (associated with process) AE
Tube mills AJ KJ Tubes (electrical) - V Tubs BB KD Tumbler switches - S Tun dishes MR Tunnel diodes - V
Turbines (not main and heavy machinery) MT
Turbocompressors AN KN
Turbofans AN KN
Turning gear AE KE
Turntables (for railway vehicles) AE KE
TV cameras - E
Ultrasonic cleaning equipment AT
Ultrasonic instruments - B
Underfeed stokers AV KV
Uniselectors - S
Universal- fuel engines (non- electrical) MM
Universal motors (electrical) - M
Vacuum breakers AA KA
Valve assemblies (valve blank) AA
Valve boxes KA
Valve chests KA
Valves, excl. Actuators KA
Vane pumps AP KP
Vapor compression refrigerators AH
Vapor extractors AN KN
Vaposcopes AA KA
Variable capacitance diodes - V
Vent valves AA KA
Ventilation ducts BR MR
Venturis QB
Vessel level measuring circuits CL
Vibrating control circuits DY
Vibrating conveyors AF KF
Vibrating screens AT KT
Vibration detectors (electrical) - B
Vibration measuring circuits, direct CY
Vibration measuring circuits, indirect FY
Vibration measuring instruments (non- electrical) QV
Vibration sensors - B
Vibration transducers - B
Vibrators (for separating) AT KT
Video display units - P
Video screens - E
Viscosity control circuits DV
Viscosity measuring circuits, direct CV
Viscosity measuring circuits, indirect FV
Viscosity measuring instruments (non- electrical) QP
Viscosity sensors (electrical) - B
Voltage measuring circuits (electrical) CE
Voltage monitors - F
Voltage operated earth- leakage circuit- breakers - F
Voltage transformers - T
Volume measuring circuits (for vessels) CL
Volume measuring circuits (not for vessels) CU
Volumetric flow measuring circuits CF
Volumetric flow rate measuring circuits CF
Volumetric flow sensors (electrical) - B
Volumetric flow sensors (non- electrical) QB
Waldron couplings MK
Washing machines AT
Water meters QP
Water- operated air ejectors BN
Water- operated jet pumps BN
Water soot- blowers AT KT
Waterhammer suppressors AA KA
Wave traps (electrical) - L
Weighing machines QB
Weighing machines as measuring circuits CW
Weight control circuits DW
Weight measuring circuits CW
Weight measuring circuits, direct CW
Weight measuring circuits, indirect FW
Weight measuring instruments (non- electrical) QP
Weight transducers (electrical) - B
Weirs AB
Welding machines AW
Winches AE KE
Windows AB KB
Work meters - P
