|  | F |
SECTION F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

|  | F01 - F04 |
Subsection index
MACHINES |
positive displacement |
rotary or oscillating piston |
liquid and elastic fluid or elastic fluid | F01C
liquid only | F04C
reciprocating piston or other |
liquid and elastic fluid or elastic fluid | F01B
liquid only | F04B
non-positive displacement |
liquid and elastic fluid or elastic fluid | F01D
liquid only | F03B
ENGINES |
positive displacement |
rotary or oscillating piston |
liquid and elastic fluid or elastic fluid | F01C
liquid only | F03C
reciprocating piston or other |
liquid and elastic fluid or elastic fluid | F01B
liquid only | F03C
non-positive displacement |
liquid and elastic fluid or elastic fluid | F01D
liquid only | F03B
PUMPS |
positive displacement |
rotary or oscillating piston | F04C
reciprocating piston or other | F04B
non-positive displacement | F04D

LIGHTING; HEATING

|  | F22 |
STEAM GENERATION (chemical or physical apparatus for generating gases Fulltext... Hierarchy... Expanded...B01J; chemical generation of gas, e.g. under pressure, Section C; removal of combustion products or residues, e.g. cleaning of the combustion contaminated surfaces of tubes of boilers, Fulltext... Hierarchy... Expanded...F23J; generating combustion products of high pressure or high velocity Fulltext... Hierarchy... Expanded...F23R; water heaters not for steam generation Fulltext... Hierarchy... Expanded...F24H, Fulltext... Hierarchy... Expanded...F28; cleaning of internal or external surfaces of heat-transfer conduits, e.g. water tubes of boilers, Fulltext... Hierarchy... Expanded...F28G)

|  | F22 |
Note(s) In this class, the following term is used with the meaning indicated: "steam" covers also other condensable vapours, e.g. mercury, diphenyl, diphenyl oxide.

|  | F22B |
METHODS OF STEAM GENERATION; STEAM BOILERS (steam engine plants where engine aspects predominate Fulltext... Hierarchy... Expanded...F01K; domestic central-heating systems using steam Fulltext... Hierarchy... Expanded...F24D; heat exchange or heat transfer in general Fulltext... Hierarchy... Expanded...F28; generation of vapour in the cores of nuclear reactors Fulltext... Hierarchy... Expanded...G21)

|  | F22B |
Note(s) This subclass covers only methods of, or apparatus for, the generation of steam under pressure for heating or power purposes.

|  | F22B |
Subclass index
METHODS FOR STEAM GENERATION | 1/00, 3/00
STEAM BOILERS |
General characteristics |
having drum; having furnace tube; having fire tube; having combined fire tube and water tube; having fire-box | 5/00; 7/00; 9/00; 11/00; 13/00
having water tubes |
auxiliary tubes | 11/00
horizontal; horizontally-inclined; combined horizontally-inclined and vertical; vertical or steeply-inclined | 15/00; 17/00; 19/00; 21/00
formed of sets of spaced double-walled water tubes or of return tubes; water tubes with internally-arranged flue tubes | 23/00; 25/00
Special characteristics | 27/00, 29/00
Modifications or arrangements; details of general application | 31/00; 37/00
PLANTS; CONTROL SYSTEMS | 33/00; 35/00

|  | F22B 1/00 - F22B 3/00 |
General aspects of, or methods for, steam generation

P:0 |  | F22B 1/00 |
Methods of steam generation characterised by form of heating method (use of solar heat Fulltext... Hierarchy... Expanded...F24J 2/00; jackets or other cooling means in which steam is generated and which serve for cooling other apparatus, see the subclasses for such apparatus)

|  | F22B 1/02 |
· | by exploitation of the heat content of hot heat carriers

|  | F22B 1/04 |
· · | the heat carrier being hot slag, hot residues, or heated blocks, e.g. iron blocks

|  | F22B 1/06 |
· · | the heat carrier being molten; Use of molten metal, e.g. zinc, as heat transfer medium

|  | F22B 1/08 |
· · | the heat carrier being steam

|  | F22B 1/10 |
· · · | released from heat accumulators

|  | F22B 1/12 |
· · · | produced by an indirect cyclic process

|  | F22B 1/14 |
· · · | coming in direct contact with water in bulk or in sprays

|  | F22B 1/16 |
· · | the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour

|  | F22B 1/18 |
· · | the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines (use of waste heat of combustion engines, in general, Fulltext... Hierarchy... Expanded...F02)

|  | F22B 1/20 |
· | using heat evolved in a solution absorbing steam; Soda steam boilers

|  | F22B 1/22 |
· | using combustion under pressure substantially exceeding atmospheric pressure

|  | F22B 1/24 |
· · | Pressure-fired steam boilers, e.g. using turbo air compressors actuated by hot gases from boiler furnace

|  | F22B 1/26 |
· · | Steam boilers of submerged-flame type, i.e. the flame being surrounded by, or impinging on, the water to be vaporised

|  | F22B 1/28 |
· | in boilers heated electrically

|  | F22B 1/30 |
· · | Electrode boilers

P:10 |  | F22B 3/00 |
Other methods of steam generation

|  | F22B 3/02 |
· | involving the use of working media other than water

|  | F22B 3/04 |
· | by drop in pressure of high-pressure hot water within pressure-reducing chambers, e.g. in accumulators (steam accumulators per se Fulltext... Hierarchy... Expanded...F01K 1/00)

|  | F22B 3/06 |
· | by transformation of mechanical, e.g. kinetic, energy into heat energy

|  | F22B 3/08 |
· | at critical or supercritical pressure values

|  | F22B 5/00 - F22B 31/00 |
Kinds of steam boilers

P:170 |  | F22B 5/00 |
Steam boilers of drum type, i.e. without internal furnace or fire tubes, the boiler body being contacted externally by flue gas

|  | F22B 5/02 |
· | with auxiliary water tubes outside the boiler body

|  | F22B 5/04 |
· | Component parts thereof; Accessories therefor (covers or similar closure members for pressure vessels in general Fulltext... Hierarchy... Expanded...F16J 13/00)

P:160 |  | F22B 7/00 |
Steam boilers of furnace-tube type, i.e. the combustion of fuel being performed inside one or more furnace tubes built-in in the boiler body

|  | F22B 7/02 |
· | without auxiliary water tubes

|  | F22B 7/04 |
· | with auxiliary water tubes

|  | F22B 7/06 |
· · | inside the furnace tube in transverse arrangement

|  | F22B 7/08 |
· · | inside the furnace tube in longitudinal arrangement

|  | F22B 7/10 |
· · | outside the boiler body

|  | F22B 7/12 |
· | with auxiliary fire tubes; Arrangement of header boxes providing for return diversion of flue gas flow

|  | F22B 7/14 |
· | with both auxiliary water tubes and auxiliary fire tubes

|  | F22B 7/16 |
· | Component parts thereof; Accessories therefor, e.g. stay-bolt connections

|  | F22B 7/18 |
· · | Walling of flues; Flue-gas header boxes

|  | F22B 7/20 |
· · | Furnace tubes

P:150 |  | F22B 9/00 |
Steam boilers of fire-tube type, i.e. the flue gas from a combustion chamber outside the boiler body flowing through tubes built-in in the boiler body

|  | F22B 9/02 |
· | the boiler body being disposed upright, e.g. above the combustion chamber

|  | F22B 9/04 |
· · | the fire tubes being in upright arrangement

|  | F22B 9/06 |
· · · | Arrangement of header boxes providing for return diversion of flue gas flow

|  | F22B 9/08 |
· · | the fire tubes being in horizontal arrangement

|  | F22B 9/10 |
· | the boiler body being disposed substantially horizontally, e.g. at the side of the combustion chamber

|  | F22B 9/12 |
· · | the fire tubes being in substantially-horizontal arrangement

|  | F22B 9/14 |
· · · | Arrangement of header boxes providing for return diversion of flue gas flow

|  | F22B 9/16 |
· | the boiler body containing fire tubes disposed crosswise in inclined upward arrangement

|  | F22B 9/18 |
· | Component parts thereof; Accessories therefor, e.g. stay-bolt connections

P:80 |  | F22B 11/00 |
Steam boilers of combined fire-tube type and water-tube type, i.e. steam boilers of fire-tube type having auxiliary water tubes

|  | F22B 11/02 |
· | the fire tubes being in upright arrangement

|  | F22B 11/04 |
· | the fire tubes being in horizontal arrangement

P:140 |  | F22B 13/00 |
Steam boilers of fire-box type, i.e. the combustion of fuel being performed in a chamber or fire-box with subsequent flue(s) or fire tube(s), both chamber or fire-box and flues or fire tubes being built-in in the boiler body

|  | F22B 13/02 |
· | mounted in fixed position with the boiler body disposed upright

|  | F22B 13/04 |
· | mounted in fixed position with the boiler body disposed substantially horizontally

|  | F22B 13/06 |
· | Locomobile, traction-engine, steam-roller, or locomotive boilers

|  | F22B 13/08 |
· · | without auxiliary water tubes inside the fire-box

|  | F22B 13/10 |
· · | with auxiliary water tubes inside the fire-box

|  | F22B 13/12 |
· · · | the auxiliary water tubes lining the fire-box

|  | F22B 13/14 |
· | Component parts thereof; Accessories therefor

|  | F22B 13/16 |
· · | Stay-bolt connections, e.g. rigid connections

|  | F22B 13/18 |
· · · | Flexible connections, e.g. of ball-and-socket type

P:110 |  | F22B 15/00 |
Water-tube boilers of horizontal type, i.e. the water-tube sets being arranged horizontally

P:120 |  | F22B 17/00 |
Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane

|  | F22B 17/02 |
· | built-up from water-tube sets in abutting connection with two header boxes in common for all sets, e.g. with flat header boxes

|  | F22B 17/04 |
· · | the water-tube sets being inclined in opposite directions, e.g. crosswise

|  | F22B 17/06 |
· · | the water-tube sets being bent angularly

|  | F22B 17/08 |
· · | the water-tube sets being curved

|  | F22B 17/10 |
· | built-up from water-tube sets in abutting connection with two sectional headers each for every set, i.e. with headers in a number of sections across the width or height of the boiler

|  | F22B 17/12 |
· · | the sectional headers being in vertical or substantially-vertical arrangement

|  | F22B 17/14 |
· · | the sectional headers being in horizontal or substantially-horizontal arrangement

|  | F22B 17/16 |
· | Component parts thereof; Accessories therefor

|  | F22B 17/18 |
· · | Header boxes; Sectional headers

P:100 |  | F22B 19/00 |
Water-tube boilers of combined horizontally-inclined type and vertical type, i.e. water-tube boilers of horizontally-inclined type having auxiliary water-tube sets in vertical or substantially-vertical arrangement

P:130 |  | F22B 21/00 |
Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically

|  | F22B 21/02 |
· | built-up from substantially-straight water tubes

|  | F22B 21/04 |
· · | involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely

|  | F22B 21/06 |
· · · | the water tubes being arranged annularly in sets, e.g. in abutting connection with drums of annular shape

|  | F22B 21/08 |
· · · | the water tubes being arranged sectionally in groups or in banks, e.g. bent over at their ends

|  | F22B 21/10 |
· · · | the water tubes being arranged in staggered rows

|  | F22B 21/12 |
· · | involving two or more upper drums and two or more lower drums, e.g. with crosswise-arranged water-tube sets in abutting connection with drums

|  | F22B 21/14 |
· · | involving a single upper drum and two or more lower drums

|  | F22B 21/16 |
· · · | the lower drums being interconnected by further water tubes

|  | F22B 21/18 |
· · | involving two or more upper drums and a single lower drum

|  | F22B 21/20 |
· · | involving sectional or subdivided headers in separate arrangement for each water-tube set

|  | F22B 21/22 |
· | built-up from water tubes of form other than straight or substantially straight

|  | F22B 21/24 |
· · | bent in serpentine or sinuous form

|  | F22B 21/26 |
· · | bent helically, i.e. coiled

|  | F22B 21/28 |
· · | bent spirally

|  | F22B 21/30 |
· · | bent in U-loop form

|  | F22B 21/32 |
· · · | disposed horizontally in abutting connection with upright headers or rising water mains

|  | F22B 21/34 |
· | built-up from water tubes grouped in panel form surrounding the combustion chamber, i.e. radiation boilers

|  | F22B 21/36 |
· · | involving an upper drum or headers mounted at the top of the combustion chamber

|  | F22B 21/38 |
· · | Component parts thereof, e.g. prefabricated panels

|  | F22B 21/40 |
· | built-up from water tubes arranged in a comparatively long vertical shaft, i.e. tower boilers

P:90 |  | F22B 23/00 |
Water-tube boilers built-up from sets of spaced double-walled water tubes of return type in unilaterial abutting connection with a boiler drum or with a header box, i.e. built-up from Field water tubes comprising an inner tube arranged within an outer unilaterally-closed tube

|  | F22B 23/02 |
· | the water-tube, i.e. Field-tube, sets being horizontal or substantially horizontal

|  | F22B 23/04 |
· | the water-tube, i.e. Field-tube, sets being vertical or substantially vertical

|  | F22B 23/06 |
· | Component parts thereof, e.g. Field water tubes (heat-exchange tubes in general Fulltext... Hierarchy... Expanded...F28F)

P:70 |  | F22B 25/00 |
Water-tube boilers built-up from sets of water tubes with internally-arranged flue tubes, or fire tubes, extending through the water tubes

P:50 |  | F22B 27/00 |
Instantaneous or flash steam boilers

|  | F22B 27/02 |
· | built-up from fire tubes

|  | F22B 27/04 |
· | built-up from water tubes (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...F22B 27/12-F22B 27/16 take precedence)

|  | F22B 27/06 |
· · | bent in serpentine or sinuous form

|  | F22B 27/08 |
· · | bent helically, i.e. coiled

|  | F22B 27/10 |
· · | bent spirally

|  | F22B 27/12 |
· | built-up from rotary heat-exchange elements, e.g. from tube assemblies

|  | F22B 27/14 |
· | built-up from heat-exchange elements arranged within a confined chamber having heat-retaining walls

|  | F22B 27/16 |
· | involving spray nozzles for sprinkling or injecting water particles on to or into hot heat-exchange elements, e.g. into tubes

P:60 |  | F22B 29/00 |
Steam boilers of forced-flow type

|  | F22B 29/02 |
· | of forced-circulation type

|  | F22B 29/04 |
· | of combined-circulation type, i.e. in which convection circulation due to the difference in specific gravity between cold and hot water is promoted by additional measures, e.g. by injecting pressure-water temporarily

|  | F22B 29/06 |
· | of once-through type, i.e. built-up from tubes receiving water at one end and delivering superheated steam at the other end of the tubes (Fulltext... Hierarchy... Expanded...F22B 33/00 takes precedence)

|  | F22B 29/08 |
· · | operating with fixed point of final state of complete evaporation

|  | F22B 29/10 |
· · | operating with sliding point of final state of complete evaporation

|  | F22B 29/12 |
· · | operating with superimposed recirculation during starting and low-load periods, e.g. composite boilers

P:40 |  | F22B 31/00 |
Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements or dispositions of combustion apparatus (steam generation characterised by heating method Fulltext... Hierarchy... Expanded...F22B 1/00; combustion apparatus per se Fulltext... Hierarchy... Expanded...F23)

|  | F22B 31/02 |
· | Installation of water-tube boilers in chimneys, e.g. in converter chimneys

|  | F22B 31/04 |
· | Heat supply by installation of two or more combustion apparatus, e.g. of separate combustion apparatus for the boiler and the superheater respectively

|  | F22B 31/06 |
· · | Installation of emergency heat supply

|  | F22B 31/08 |
· | Installation of heat-exchange apparatus or of means in boilers for heating air supplied for combustion

|  | F22B 33/00 - F22B 35/00 |
Steam-generation plants; Control systems

P:30 |  | F22B 33/00 |
Steam-generation plants, e.g. comprising steam boilers of different types in mutual association (arrangements or dispositions of steam-generation plants in marine vessels Fulltext... Hierarchy... Expanded...B63H 21/00)

|  | F22B 33/02 |
· | Combinations of boilers having a single combustion apparatus in common

|  | F22B 33/04 |
· · | of boilers of furnace-tube type with boilers of water-tube type

|  | F22B 33/06 |
· · | of boilers of furnace-tube type with boilers of fire-tube type

|  | F22B 33/08 |
· · | of boilers of water-tube type with boilers of fire-tube type

|  | F22B 33/10 |
· · | of two or more superposed boilers with separate water volumes and operating with two or more separate water levels

|  | F22B 33/12 |
· | Self-contained steam boilers, i.e. comprising as a unit the steam boiler, the combustion apparatus, the fuel storage, accessory machines, and equipment

|  | F22B 33/14 |
· | Combinations of low- and high-pressure boilers

|  | F22B 33/16 |
· · | of forced-flow type

|  | F22B 33/18 |
· | Combinations of steam boilers with other apparatus

P:20 |  | F22B 35/00 |
Control systems for steam boilers (regulation or control of steam power plants Fulltext... Hierarchy... Expanded...F01K 7/00; for regulating feed-water supply Fulltext... Hierarchy... Expanded...F22D; for controlling superheat temperature Fulltext... Hierarchy... Expanded...F22G 5/00; control of combustion Fulltext... Hierarchy... Expanded...F23N)

|  | F22B 35/02 |
· | for steam boilers with natural convection circulation

|  | F22B 35/04 |
· · | during starting-up periods, i.e. during the periods between the lighting of the furnaces and the attainment of the normal operating temperature of the steam boilers

|  | F22B 35/06 |
· | for steam boilers of forced-flow type

|  | F22B 35/08 |
· · | of forced-circulation type

|  | F22B 35/10 |
· · | of once-through type

|  | F22B 35/12 |
· · · | operating at critical or supercritical pressure

|  | F22B 35/14 |
· · | during the starting-up periods, i.e. during the periods between the lighting of the furnaces and the attainment of the normal operating temperature of the steam boilers

|  | F22B 35/16 |
· · | responsive to the percentage of steam in the mixture of steam and water

|  | F22B 35/18 |
· | Applications of computers to steam-boiler control

P:180 |  | F22B 37/00 |
Component parts or details of steam boilers (venting devices Fulltext... Hierarchy... Expanded...F16K 24/00; steam traps or like apparatus Fulltext... Hierarchy... Expanded...F16T)

|  | F22B 37/02 |
· | applicable to more than one kind or type of steam boiler

|  | F22B 37/04 |
· · | and characterised by material, e.g. use of special steel alloy

|  | F22B 37/06 |
· · | Flue or fire tubes; Accessories therefor, e.g. fire-tube inserts

|  | F22B 37/08 |
· · · | Fittings preventing burning-off of the tube edges

|  | F22B 37/10 |
· · | Water tubes; Accessories therefor (working of metal tubes Fulltext... Hierarchy... Expanded...B21D; pipes in general Fulltext... Hierarchy... Expanded...F16L; repairing leaks in water tubes Fulltext... Hierarchy... Expanded...F16L 55/16, Fulltext... Hierarchy... Expanded...F28F 11/00; cleaning water tubes of boilers Fulltext... Hierarchy... Expanded...F23J, Fulltext... Hierarchy... Expanded...F28G; baffles, screens, or deflectors formed of water tubes Fulltext... Hierarchy... Expanded...F23M 9/10)

|  | F22B 37/12 |
· · · | Forms of water tubes, e.g. of varying cross-section

|  | F22B 37/14 |
· · · | Supply mains, e.g. rising mains, down-comers, in connection with water tubes

|  | F22B 37/16 |
· · · | Return bends

|  | F22B 37/18 |
· · · | Inserts, e.g. for receiving deposits from water

|  | F22B 37/20 |
· · · | Supporting arrangements, e.g. for securing water-tube sets (construction of tube walls of furnaces including boiler furnaces Fulltext... Hierarchy... Expanded...F23M 5/08)

|  | F22B 37/22 |
· · | Drums; Headers; Accessories therefor (making boilers from sheet metal Fulltext... Hierarchy... Expanded...B21D 51/24; pressure vessels in general Fulltext... Hierarchy... Expanded...F16J 12/00; covers or similar closure members for pressure vessels in general Fulltext... Hierarchy... Expanded...F16J 13/00)

|  | F22B 37/24 |
· · | Supporting, suspending, or setting arrangements, e.g. heat shielding (frames, engine beds Fulltext... Hierarchy... Expanded...F16M)

|  | F22B 37/26 |
· · | Steam-separating arrangements (vapour-liquid separators, e.g. for drying steam, Fulltext... Hierarchy... Expanded...B01D, Fulltext... Hierarchy... Expanded...B04)

|  | F22B 37/28 |
· · · | involving reversal of direction of flow

|  | F22B 37/30 |
· · · | using impingement against baffle separators

|  | F22B 37/32 |
· · · | using centrifugal force

|  | F22B 37/34 |
· · | Adaptations of boilers for promoting water circulation (auxiliary apparatus Fulltext... Hierarchy... Expanded...F22D 7/00)

|  | F22B 37/36 |
· · | Arrangements for sheathing or casing boilers

|  | F22B 37/38 |
· · | Determining or indicating operating conditions in steam boilers, e.g. monitoring direction or rate of water flow through water tubes (measuring or indicating instruments in general Fulltext... Hierarchy... Expanded...G01)

|  | F22B 37/40 |
· · | Arrangements of partition walls in flues of steam boilers, e.g. built-up from baffles (in flues or chimneys Fulltext... Hierarchy... Expanded...F23J 13/00)

|  | F22B 37/42 |
· · | Applications, arrangements, or dispositions of alarm or automatic safety devices (for feed-water heaters Fulltext... Hierarchy... Expanded...F22D 1/14; alarms responsive to undesired or abnormal conditions Fulltext... Hierarchy... Expanded...G08B)

|  | F22B 37/44 |
· · · | of safety valves (safety valves per se Fulltext... Hierarchy... Expanded...F16K)

|  | F22B 37/46 |
· · · | responsive to low or high water level, e.g. for checking, suppressing, extinguishing combustion in boilers (fire-fighting, fire extinction in general Fulltext... Hierarchy... Expanded...A62)

|  | F22B 37/47 |
· · · | responsive to abnormal temperature, e.g. actuated by fusible plugs (such alarms or devices per se Fulltext... Hierarchy... Expanded...G08B)

|  | F22B 37/48 |
· · | Devices or arrangements for removing water, minerals, or sludge from boilers (cleaning water tubes, furnace tubes, or the like of boilers Fulltext... Hierarchy... Expanded...F23J, Fulltext... Hierarchy... Expanded...F28G)

|  | F22B 37/48 |
Note(s) Group Fulltext... Hierarchy... Expanded...F22B 37/48 covers only systems used while the boiler is in operation, or which remain in position while the boiler is in operation, or are specifically adapted to boilers without any other utility. [4]

|  | F22B 37/50 |
· · · | for draining or expelling water

|  | F22B 37/52 |
· · · | Washing-out devices

|  | F22B 37/54 |
· · · | De-sludging or blow-down devices

|  | F22B 37/56 |
· · | Boiler-cleaning control devices, e.g. for ascertaining proper duration of boiler blow-down

|  | F22B 37/58 |
· · | Removing tubes from headers or drums; Extracting tools

|  | F22B 37/60 |
· | specially adapted for steam boilers of instantaneous or flash type

|  | F22B 37/62 |
· | specially adapted for steam boilers of forced-flow type

|  | F22B 37/64 |
· · | Mounting of, or supporting arrangements for, tube units (construction of tube walls of furnaces, e.g. boiler furnaces Fulltext... Hierarchy... Expanded...F23M 5/08)

|  | F22B 37/66 |
· · · | involving vertically-disposed water tubes

|  | F22B 37/68 |
· · · | involving horizontally-disposed water tubes

|  | F22B 37/70 |
· · | Arrangements for distributing water into water tubes

|  | F22B 37/72 |
· · · | involving injection devices

|  | F22B 37/74 |
· · · | Throttling arrangements for tubes or sets of tubes

|  | F22B 37/76 |
· | Adaptations or mounting of devices for observing existence or direction of fluid flow (devices per se Fulltext... Hierarchy... Expanded...G01P)

|  | F22B 37/78 |
· | Adaptations or mounting of level indicators (level indicators per se Fulltext... Hierarchy... Expanded...G01F)