F22B1/00	7	Methods of steam generation characterised by form of heating method	F22B1/00	F22B1/00		650
F22B1/003	8	{using combustion of hydrogen with oxygen}	F22B1/00	F22B1/00		196
F22B1/006	8	{using solar heat}	F22B1/00	F22B1/00		1068
F22B1/02	8	by exploitation of the heat content of hot heat carriers	F22B1/02	F22B1/02		314
F22B1/021	9	{with heating tubes in which flows a non-specified heating fluid (for nuclear reactors F22B1/023)}	F22B1/02	F22B1/02		119
F22B1/023	9	{with heating tubes for nuclear reactors, as long as they are not classified according to a specified heating fluid, in another group}	F22B1/02	F22B1/02		228
F22B1/025	10	{with vertical U shaped tubes carried on a horizontal tube sheet}	F22B1/02	F22B1/02		215
F22B1/026	10	{with vertical tubes between two horizontal tube sheets}	F22B1/02	F22B1/02		45
F22B1/028	9	{Steam generation using heat accumulators (F22B27/14 takes precedence)}	F22B1/02	F22B1/02		395
F22B1/04	9	the heat carrier being hot slag, hot residues, or heated blocks, e.g. iron blocks	F22B1/04	F22B1/04		341
F22B1/06	9	the heat carrier being molten; Use of molten metal, e.g. zinc, as heat transfer medium	F22B1/06	F22B1/06		448
F22B1/063	10	{for metal cooled nuclear reactors}	F22B1/06	F22B1/06		283
F22B1/066	11	{with double-wall tubes having a third fluid between these walls, e.g. helium for leak detection}	F22B1/06	F22B1/06		40
F22B1/08	9	the heat carrier being steam	F22B1/08	F22B1/08		426
F22B1/10	10	released from heat accumulators	F22B1/10	F22B1/10		19
F22B1/12	10	produced by an indirect cyclic process	F22B1/12	F22B1/12		91
F22B1/123	11	{Steam generators downstream of a nuclear boiling water reactor}	F22B1/12	F22B1/12		31
F22B1/126	11	{Steam generators of the Schmidt-Hartmann type}	F22B1/12	F22B1/12		110
F22B1/14	10	coming in direct contact with water in bulk or in sprays	F22B1/14	F22B1/14		95
F22B1/143	11	{in combination with a nuclear installation}	F22B1/14	F22B1/14		31
F22B1/146	11	{Loffler boilers}	F22B1/14	F22B1/14		104
F22B1/16	9	the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour	F22B1/16	F22B1/16		541
F22B1/162	10	{in combination with a nuclear installation}	F22B1/16	F22B1/16		159
F22B1/165	10	{using heat pipes}	F22B1/16	F22B1/16		83
F22B1/167	10	{using an organic fluid}	F22B1/16	F22B1/16		84
F22B1/18	9	the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines	F22B1/18	F22B1/18		1967
F22B1/1807	10	{using the exhaust gases of combustion engines}	F22B1/18	F22B1/18		586
F22B1/1815	11	{using the exhaust gases of gas-turbines}	F22B1/18	F22B1/18		669
F22B1/1823	10	{for gas-cooled nuclear reactors}	F22B1/18	F22B1/18		254
F22B1/183	10	{in combination with metallurgical converter installations}	F22B1/18	F22B1/18		145
F22B1/1838	10	{the hot gas being under a high pressure, e.g. in chemical installations}	F22B1/18	F22B1/18		173
F22B1/1846	11	{the hot gas being loaded with particles, e.g. waste heat boilers after a coal gasification plant}	F22B1/18	F22B1/18		158
F22B1/1853	10	{coming in direct contact with water in bulk or in sprays}	F22B1/18	F22B1/18		118
F22B1/1861	10	{Waste heat boilers with supplementary firing}	F22B1/18	F22B1/18		197
F22B1/1869	10	{Hot gas water tube boilers not provided for in F22B1/1807 - F22B1/1861}	F22B1/18	F22B1/18		197
F22B1/1876	11	{the hot gas being loaded with particles, e.g. dust}	F22B1/18	F22B1/18		103
F22B1/1884	10	{Hot gas heating tube boilers with one or more heating tubes}	F22B1/18	F22B1/18		226
F22B1/1892	10	{Systems therefor not provided for in F22B1/1807&#160;-&#160;F22B1/1861}	F22B1/18	F22B1/18		305
F22B1/20	8	using heat evolved in a solution absorbing steam; Soda steam boilers	F22B1/20	F22B1/20		93
F22B1/22	8	using combustion under pressure substantially exceeding atmospheric pressure	F22B1/22	F22B1/22		1083
F22B1/24	9	Pressure-fired steam boilers, e.g. using turbo air compressors actuated by hot gases from boiler furnace	F22B1/24	F22B1/24		76
F22B1/26	9	Steam boilers of submerged-flame type, i.e. the flame being surrounded by, or impinging on, the water to be vaporised	F22B1/26	F22B1/26		235
F22B1/265	10	{the water being in bulk}	F22B1/26	F22B1/26		66
F22B1/28	8	in boilers heated electrically	F22B1/28	F22B1/28		1717
F22B1/281	9	{other than by electrical resistances or electrodes}	F22B1/28	F22B1/28		328
F22B1/282	9	{with water or steam circulating in tubes or ducts}	F22B1/28	F22B1/28		348
F22B1/284	9	{with water in reservoirs}	F22B1/28	F22B1/28		1219
F22B1/285	10	{the water being fed by a pump to the reservoirs}	F22B1/28	F22B1/28		275
F22B1/287	9	{with water in sprays or in films}	F22B1/28	F22B1/28		228
F22B1/288	9	{Instantaneous electrical steam generators built-up from heat-exchange elements arranged within a confined chamber having heat-retaining walls}	F22B1/28	F22B1/28		180
F22B1/30	9	Electrode boilers	F22B1/30	F22B1/30		865
F22B1/303	10	{with means for injecting or spraying water against electrodes or with means for water circulation}	F22B1/30	F22B1/30		109
F22B1/306	11	{with at least one electrode permanently above the water surface}	F22B1/30	F22B1/30		67
F22B3/00	7	Other methods of steam generation; Steam boilers not provided for in other groups of this subclass	F22B3/00	F22B3/00		172
F22B3/02	8	involving the use of working media other than water	F22B3/02	F22B3/02		388
F22B3/04	8	by drop in pressure of high-pressure hot water within pressure-reducing chambers, e.g. in accumulators	F22B3/04	F22B3/04		587
F22B3/045	9	{the drop in pressure being achieved by compressors, e.g. with steam jet pumps}	F22B3/04	F22B3/04		89
F22B3/06	8	by transformation of mechanical, e.g. kinetic, energy into heat energy	F22B3/06	F22B3/06		237
F22B3/08	8	at critical or supercritical pressure values	F22B3/08	F22B3/08		114
F22B5/00	7	Steam boilers of drum type, i.e. without internal furnace or fire tubes, the boiler body being contacted externally by flue gas	F22B5/00	F22B5/00		106
F22B5/005	8	{with rotating drums}	F22B5/00	F22B5/00		70
F22B5/02	8	with auxiliary water tubes outside the boiler body	F22B5/02	F22B5/02		61
F22B5/04	8	Component parts thereof; Accessories therefor	F22B5/04	F22B5/04		18
F22B7/00	7	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	F22B7/00	F22B7/00		213
F22B7/02	8	without auxiliary water tubes	F22B7/02	F22B7/02		35
F22B7/04	8	with auxiliary water tubes	F22B7/04	F22B7/04		72
F22B7/06	9	inside the furnace tube in transverse arrangements	F22B7/06	F22B7/06		61
F22B7/08	9	inside the furnace tube in longitudinal arrangement	F22B7/08	F22B7/08		14
F22B7/10	9	outside the boiler body	F22B7/10	F22B7/10		5
F22B7/12	8	with auxiliary fire tubes; Arrangement of header boxes providing for return diversion of flue gas flow	F22B7/12	F22B7/12		492
F22B7/14	8	with both auxiliary water tubes and auxiliary fire tubes	F22B7/14	F22B7/14		36
F22B7/16	8	Component parts thereof; Accessories therefor, e.g. stay-bolt connections	F22B7/16	F22B7/16		593
F22B7/18	9	Walling of flues; Flue-gas header boxes	F22B7/18	F22B7/18		15
F22B7/20	9	Furnace tubes	F22B7/20	F22B7/20		88
F22B9/00	7	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	F22B9/00	F22B9/00		79
F22B9/02	8	the boiler body being disposed upright, e.g. above the combustion chamber	F22B9/02	F22B9/02		23
F22B9/04	9	the fire tubes being in upright arrangement	F22B9/04	F22B9/04		516
F22B9/06	10	Arrangement of header boxes providing for return diversion of flue gas flow	F22B9/06	F22B9/06		8
F22B9/08	9	the fire tubes being in horizontal arrangement	F22B9/08	F22B9/08		56
F22B9/10	8	the boiler body being disposed substantially horizontally, e.g. at the side of the combustion chamber	F22B9/10	F22B9/10		32
F22B9/12	9	the fire tubes being in substantially-horizontal arrangement	F22B9/12	F22B9/12		587
F22B9/14	10	Arrangement of header boxes providing for return diversion of flue gas flow	F22B9/14	F22B9/14		27
F22B9/16	8	the boiler body containing fire tubes disposed crosswise in inclined upward arrangement	F22B9/16	F22B9/16		8
F22B9/18	8	Component parts thereof; Accessories therefor, e.g. stay-bolt connections	F22B9/18	F22B9/18		63
F22B11/00	7	Steam boilers of combined fire-tube type and water-tube type, i.e. steam boilers of fire-tube type having auxiliary water tubes	F22B11/00	F22B11/00		439
F22B11/02	8	the fire tubes being in upright arrangement	F22B11/02	F22B11/02		35
F22B11/04	8	the fire tubes being in horizontal arrangement	F22B11/04	F22B11/04		28
F22B13/00	7	Steam boilers of fire-box type, i.e. boilers where both combustion chambers and subsequent flues or fire tubes are arranged within the boiler body	F22B13/00	F22B13/00		134
F22B13/005	8	{with flues, other than fire tubes}	F22B13/00	F22B13/00		195
F22B13/02	8	mounted in fixed position with the boiler body disposed upright	F22B13/02	F22B13/02		91
F22B13/023	9	{with auxiliary water tubes inside the fire-box, e.g. vertical tubes (F22B13/10 takes precedence)}	F22B13/02	F22B13/02		374
F22B13/026	10	{the tubes being in substantially horizontal arrangement}	F22B13/02	F22B13/02		168
F22B13/04	8	mounted in fixed position with the boiler body disposed substantially horizontally	F22B13/04	F22B13/04		108
F22B13/06	8	Locomobile, traction-engine, steam-roller, or locomotive boilers	F22B13/06	F22B13/06		213
F22B13/065	9	{Combination of low- and high-pressure locomotive boilers}	F22B13/06	F22B13/06		62
F22B13/08	9	without auxiliary water tubes inside the fire-box	F22B13/08	F22B13/08		243
F22B13/10	9	with auxiliary water tubes inside the fire-box	F22B13/10	F22B13/10		154
F22B13/12	10	the auxiliary water tubes lining the fire-box	F22B13/12	F22B13/12		174
F22B13/14	8	Component parts thereof; Accessories therefor	F22B13/14	F22B13/14		61
F22B13/145	9	{Firebox thermosiphons}	F22B13/14	F22B13/14		231
F22B13/16	9	Stay-bolt connections, e.g. rigid connections	F22B13/16	F22B13/16		4
F22B13/18	10	Flexible connections, e.g. of ball-and-socket type	F22B13/18	F22B13/18		5
F22B15/00	7	Water-tube boilers of horizontal type, i.e. the water-tube sets being arranged horizontally	F22B15/00	F22B15/00		111
F22B17/00	7	Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane	F22B17/00	F22B17/00		134
F22B17/02	8	built-up from water-tube sets in abutting connection with two header boxes in common for all sets, e.g. with flat header boxes	F22B17/02	F22B17/02		153
F22B17/025	9	{with combined inlet and outlet header boxes, e.g. connected by U-tubes or Field tubes}	F22B17/02	F22B17/02		16
F22B17/04	9	the water-tube sets being inclined in opposite directions, e.g. crosswise	F22B17/04	F22B17/04		22
F22B17/06	9	the water-tube sets being bent angularly	F22B17/06	F22B17/06		1
F22B17/08	9	the water-tube sets being curved	F22B17/08	F22B17/08		32
F22B17/10	8	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	F22B17/10	F22B17/10		682
F22B17/105	9	{with tubes in series flow arrangement}	F22B17/10	F22B17/10		90
F22B17/12	9	the sectional headers being in vertical or substantially-vertical arrangement	F22B17/12	F22B17/12		242
F22B17/14	9	the sectional headers being in horizontal or substantially-horizontal arrangement	F22B17/14	F22B17/14		6
F22B17/16	8	Component parts thereof; Accessories therefor	F22B17/16	F22B17/16		257
F22B17/18	9	Header boxes; Sectional headers	F22B17/18	F22B17/18		14
F22B19/00	7	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	F22B19/00	F22B19/00		85
F22B21/00	7	Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically	F22B21/00	F22B21/00		258
F22B21/002	8	{involving a single upper drum (F22B21/36 takes precedence)}	F22B21/00	F22B21/00		110
F22B21/005	8	{involving a central vertical drum, header or downcomer}	F22B21/00	F22B21/00		45
F22B21/007	8	{specially adapted for locomotives}	F22B21/00	F22B21/00		189
F22B21/02	8	built-up from substantially-straight water tubes	F22B21/02	F22B21/02		103
F22B21/04	9	involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely	F22B21/04	F22B21/04		204
F22B21/06	10	the water tubes being arranged annularly in sets, e.g. in abutting connection with drums of annular shape	F22B21/06	F22B21/06		55
F22B21/065	11	{involving an upper and lower drum of annular shape}	F22B21/06	F22B21/06		113
F22B21/08	10	the water tubes being arranged sectionally in groups or in banks, e.g. bent over at their ends	F22B21/08	F22B21/08		47
F22B21/081	11	{involving a combustion chamber, placed at the side and built-up from water tubes}	F22B21/08	F22B21/08		116
F22B21/083	11	{involving an upper drum and a lower drum and a fire-place between the two drums}	F22B21/08	F22B21/08		41
F22B21/085	11	{the tubes being placed in layers}	F22B21/08	F22B21/08		26
F22B21/086	11	{Frames built-up from water tubes}	F22B21/08	F22B21/08		28
F22B21/088	11	{involving an upper drum and a lower drum and two lateral drums}	F22B21/08	F22B21/08		68
F22B21/10	10	the water tubes being arranged in staggered rows	F22B21/10	F22B21/10		3
F22B21/12	9	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	F22B21/12	F22B21/12		40
F22B21/123	10	{involving crossed water tubes}	F22B21/12	F22B21/12		5
F22B21/126	10	{involving more than two lower or upper drums}	F22B21/12	F22B21/12		231
F22B21/14	9	involving a single upper drum and two or more lower drums	F22B21/14	F22B21/14		197
F22B21/16	10	the lower drums being interconnected by further water tubes	F22B21/16	F22B21/16		6
F22B21/18	9	involving two or more upper drums and a single lower drum	F22B21/18	F22B21/18		185
F22B21/185	10	{involving more than two upper drums and a single lower drum}	F22B21/18	F22B21/18		20
F22B21/20	9	involving sectional or subdivided headers in separate arrangement for each water-tube set	F22B21/20	F22B21/20		31
F22B21/22	8	built-up from water tubes of form other than straight or substantially straight	F22B21/22	F22B21/22		173
F22B21/24	9	bent in serpentine or sinuous form	F22B21/24	F22B21/24		91
F22B21/26	9	bent helically, i.e. coiled	F22B21/26	F22B21/26		438
F22B21/28	9	bent spirally	F22B21/28	F22B21/28		38
F22B21/30	9	bent in U-loop form	F22B21/30	F22B21/30		54
F22B21/32	10	disposed horizontally in abutting connection with upright headers or rising water mains	F22B21/32	F22B21/32		8
F22B21/34	8	built-up from water tubes grouped in panel form surrounding the combustion chamber, i.e. radiation boilers	F22B21/34	F22B21/34		691
F22B21/341	9	{Vertical radiation boilers with combustion in the lower part}	F22B21/34	F22B21/34		124
F22B21/343	10	{the vertical radiation combustion chamber being connected at its upper part to a sidewards convection chamber}	F22B21/34	F22B21/34		159
F22B21/345	11	{with a tube bundle between an upper and a lower drum in the convection pass}	F22B21/34	F22B21/34		79
F22B21/346	9	{Horizontal radiation boilers}	F22B21/34	F22B21/34		237
F22B21/348	9	{Radiation boilers with a burner at the top}	F22B21/34	F22B21/34		48
F22B21/36	9	involving an upper drum or headers mounted at the top of the combustion chamber	F22B21/36	F22B21/36		51
F22B21/363	10	{involving a horizontal drum mounted in an upper corner of the boiler}	F22B21/36	F22B21/36		71
F22B21/366	10	{involving a horizontal drum mounted in the middle of the boiler}	F22B21/36	F22B21/36		10
F22B21/38	9	Component parts thereof, e.g. prefabricated panels	F22B21/38	F22B21/38		12
F22B21/40	8	built-up from water tubes arranged in a comparatively long vertical shaft, i.e. tower boilers	F22B21/40	F22B21/40		42
F22B23/00	7	Water-tube boilers built-up from sets of spaced double-walled water tubes of return type in unilateral 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	F22B23/00	F22B23/00		117
F22B23/02	8	the water-tube, i.e. Field-tube, sets being horizontal or substantially horizontal	F22B23/02	F22B23/02		119
F22B23/04	8	the water-tube, i.e. Field-tube, sets being vertical or substantially vertical	F22B23/04	F22B23/04		205
F22B23/06	8	Component parts thereof, e.g. Field water tubes	F22B23/06	F22B23/06		15
F22B25/00	7	Water-tube boilers built-up from sets of water tubes with internally-arranged flue tubes, or fire tubes, extending through the water tubes	F22B25/00	F22B25/00		219
F22B27/00	7	Instantaneous or flash steam boilers	F22B27/00	F22B27/00		83
F22B27/02	8	built-up from fire tubes	F22B27/02	F22B27/02		24
F22B27/04	8	built-up from water tubes (F22B27/12&#160;-&#160;F22B27/16 take precedence)	F22B27/04	F22B27/04		56
F22B27/06	9	bent in serpentine or sinuous form	F22B27/06	F22B27/06		36
F22B27/08	9	bent helically, i.e. coiled	F22B27/08	F22B27/08		111
F22B27/10	9	bent spirally	F22B27/10	F22B27/10		22
F22B27/12	8	built-up from rotary heat-exchange elements, e.g. from tube assemblies	F22B27/12	F22B27/12		147
F22B27/14	8	built-up from heat-exchange elements arranged within a confined chamber having heat-retaining walls {(F22B1/288 takes precedence)}	F22B27/14	F22B27/14		115
F22B27/16	8	involving spray nozzles for sprinkling or injecting water particles on to or into hot heat-exchange elements, e.g. into tubes {(F22B1/287 takes precedence)}	F22B27/16	F22B27/16		292
F22B27/165	9	{with film flow of water on heated surfaces}	F22B27/16	F22B27/16		47
F22B29/00	7	Steam boilers of forced-flow type	F22B29/00	F22B29/00		76
F22B29/02	8	of forced-circulation type	F22B29/02	F22B29/02		473
F22B29/023	9	{without drums, i.e. without hot water storage in the boiler}	F22B29/02	F22B29/02		90
F22B29/026	10	{operating at critical or supercritical pressure}	F22B29/02	F22B29/02		39
F22B29/04	8	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	F22B29/04	F22B29/04		38
F22B29/06	8	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 (combined low- and high-pressure boilers of forced-flow type F22B33/16)	F22B29/06	F22B29/06		344
F22B29/061	9	{Construction of tube walls}	F22B29/06	F22B29/06		47
F22B29/062	10	{involving vertically-disposed water tubes}	F22B29/06	F22B29/06		103
F22B29/064	10	{involving horizontally- or helically-disposed water tubes}	F22B29/06	F22B29/06		60
F22B29/065	10	{involving upper vertically disposed water tubes and lower horizontally- or helically disposed water tubes}	F22B29/06	F22B29/06		34
F22B29/067	9	{operating at critical or supercritical pressure}	F22B29/06	F22B29/06		69
F22B29/068	9	{operating with superimposed recirculation during normal operation (F22B29/12 takes precedence)}	F22B29/06	F22B29/06		3
F22B29/08	9	operating with fixed point of final state of complete evaporation	F22B29/08	F22B29/08		155
F22B29/10	9	operating with sliding point of final state of complete evaporation	F22B29/10	F22B29/10		47
F22B29/12	9	operating with superimposed recirculation during starting and low-load periods, e.g. composite boilers	F22B29/12	F22B29/12		105
F22B31/00	7	Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements or dispositions of combustion apparatus	F22B31/00	F22B31/00		881
F22B31/0007	8	{with combustion in a fluidized bed}	F22B31/00	F22B31/00		231
F22B31/0015	9	{for boilers of the water tube type}	F22B31/00	F22B31/00		50
F22B31/0023	10	{with tubes in the bed (F22B31/003 takes precedence)}	F22B31/00	F22B31/00		125
F22B31/003	10	{with tubes surrounding the bed or with water tube wall partitions}	F22B31/00	F22B31/00		76
F22B31/0038	11	{with tubes in the bed}	F22B31/00	F22B31/00		88
F22B31/0046	9	{for boilers of the shell type, e.g. with furnace box}	F22B31/00	F22B31/00		35
F22B31/0053	10	{with auxiliary water tubes}	F22B31/00	F22B31/00		32
F22B31/0061	9	{Constructional features of bed cooling}	F22B31/00	F22B31/00		43
F22B31/0069	9	{Systems therefor}	F22B31/00	F22B31/00		94
F22B31/0084	9	{with recirculation of separated solids or with cooling of the bed particles outside the combustion bed}	F22B31/00	F22B31/00		309
F22B31/0092	10	{with a fluidized heat exchange bed and a fluidized combustion bed separated by a partition, the bed particles circulating around or through that partition}	F22B31/00	F22B31/00		66
F22B31/02	8	Installation of water-tube boilers in chimneys, e.g. in converter chimneys	F22B31/02	F22B31/02		10
F22B31/04	8	Heat supply by installation of two or more combustion apparatus, e.g. of separate combustion apparatus for the boiler and the superheater respectively	F22B31/04	F22B31/04		372
F22B31/045	9	{Steam generators specially adapted for burning refuse}	F22B31/04	F22B31/04		138
F22B31/06	9	Installation of emergency heat supply	F22B31/06	F22B31/06		12
F22B31/08	8	Installation of heat-exchange apparatus or of means in boilers for heating air supplied for combustion	F22B31/08	F22B31/08		1286
F22B33/00	7	Steam-generation plants, e.g. comprising steam boilers of different types in mutual association	F22B33/00	F22B33/00		334
F22B33/02	8	Combinations of boilers having a single combustion apparatus in common	F22B33/02	F22B33/02		32
F22B33/04	9	of boilers of furnace-tube type with boilers of water-tube type	F22B33/04	F22B33/04		149
F22B33/06	9	of boilers of furnace-tube type with boilers of fire-tube type	F22B33/06	F22B33/06		5
F22B33/08	9	of boilers of water-tube type with boilers of fire-tube type	F22B33/08	F22B33/08		137
F22B33/10	9	of two or more superposed boilers with separate water volumes and operating with two or more separate water levels	F22B33/10	F22B33/10		24
F22B33/12	8	Self-contained steam boilers, i.e. comprising as a unit the steam boiler, the combustion apparatus, the fuel storage, accessory machines and equipment	F22B33/12	F22B33/12		54
F22B33/14	8	Combinations of low- and high-pressure boilers {(combination of low- and high-pressure locomotive boilers of fire-box type F22B13/065)}	F22B33/14	F22B33/14		109
F22B33/16	9	of forced-flow type	F22B33/16	F22B33/16		13
F22B33/18	8	Combinations of steam boilers with other apparatus	F22B33/18	F22B33/18		2104
F22B33/185	9	{in combination with a steam accumulator}	F22B33/18	F22B33/18		100
F22B35/00	7	Control systems for steam boilers (for regulating feed-water supply F22D5/00; for controlling superheat temperature F22G5/00)	F22B35/00	F22B35/00		2123
F22B35/001	8	{Controlling by flue-gas dampers (for superheaters F22G5/04)}	F22B35/00	F22B35/00		70
F22B35/002	8	{Control by recirculating flue gases (for superheaters F22G5/06)}	F22B35/00	F22B35/00		93
F22B35/004	8	{Control systems for steam generators of nuclear power plants}	F22B35/00	F22B35/00		144
F22B35/005	8	{Control systems for instantaneous steam boilers}	F22B35/00	F22B35/00		152
F22B35/007	8	{Control systems for waste heat boilers}	F22B35/00	F22B35/00		254
F22B35/008	8	{Control systems for two or more steam generators (automatic water-feed control for a number of steam boilers designed for different ranges of temperature and pressure F22D5/36)}	F22B35/00	F22B35/00		134
F22B35/02	8	for steam boilers with natural convection circulation	F22B35/02	F22B35/02		38
F22B35/04	9	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	F22B35/04	F22B35/04		22
F22B35/06	8	for steam boilers of forced-flow type	F22B35/06	F22B35/06		90
F22B35/08	9	of forced-circulation type	F22B35/08	F22B35/08		70
F22B35/083	10	{without drum, i.e. without hot water storage in the boiler}	F22B35/08	F22B35/08		9
F22B35/086	11	{operating at critical or supercritical pressure}	F22B35/08	F22B35/08		19
F22B35/10	9	of once-through type	F22B35/10	F22B35/10		436
F22B35/101	10	{operating with superimposed recirculation during starting or low load periods, e.g. composite boilers (F22B35/125 takes precedence)}	F22B35/10	F22B35/10		30
F22B35/102	10	{operating with fixed point of final state of complete evaporation, e.g. in a steam-water separator}	F22B35/10	F22B35/10		124
F22B35/104	10	{Control systems by injecting water (for superheaters F22G5/12)}	F22B35/10	F22B35/10		57
F22B35/105	10	{operating at sliding pressure}	F22B35/10	F22B35/10		33
F22B35/107	10	{Control systems with auxiliary heating surfaces}	F22B35/10	F22B35/10		23
F22B35/108	10	{Control systems for steam generators having multiple flow paths}	F22B35/10	F22B35/10		66
F22B35/12	10	operating at critical or supercritical pressure	F22B35/12	F22B35/12		68
F22B35/125	11	{operating with superimposed recirculation during starting or low load periods, e.g. composite boilers}	F22B35/12	F22B35/12		15
F22B35/14	9	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	F22B35/14	F22B35/14		165
F22B35/16	9	responsive to the percentage of steam in the mixture of steam and water	F22B35/16	F22B35/16		27
F22B35/18	8	Applications of computers to steam-boiler control	F22B35/18	F22B35/18		556
F22B37/00	7	Component parts or details of steam boilers	F22B37/00	F22B37/00		1076
F22B37/001	8	{Steam generators built-up from pre-fabricated elements}	F22B37/00	F22B37/00		53
F22B37/002	8	{specially adapted for nuclear steam generators, e.g. maintenance, repairing or inspecting equipment not otherwise provided for}	F22B37/00	F22B37/00		355
F22B37/003	9	{Maintenance, repairing or inspecting equipment positioned in or via the headers}	F22B37/00	F22B37/00		336
F22B37/005	10	{Positioning apparatus specially adapted therefor (F22B37/64 takes precedence)}	F22B37/00	F22B37/00		127
F22B37/006	9	{Walking equipment, e.g. walking platforms suspended at the tube sheet}	F22B37/00	F22B37/00		59
F22B37/007	9	{Installation or removal of nuclear steam generators}	F22B37/00	F22B37/00		36
F22B37/008	8	{Adaptations for flue-gas purification in steam generators}	F22B37/00	F22B37/00		238
F22B37/02	8	applicable to more than one kind or type of steam boiler	F22B37/02	F22B37/02		380
F22B37/025	9	{Devices and methods for diminishing corrosion, e.g. by preventing cooling beneath the dew point}	F22B37/02	F22B37/02		203
F22B37/04	9	and characterised by material, e.g. use of special steel alloy	F22B37/04	F22B37/04		168
F22B37/06	9	Flue or fire tubes; Accessories therefor, e.g. fire-tube inserts	F22B37/06	F22B37/06		372
F22B37/08	10	Fittings preventing burning-off of the tube edges	F22B37/08	F22B37/08		27
F22B37/10	9	Water tubes; Accessories therefor	F22B37/10	F22B37/10		575
F22B37/101	10	{Tubes having fins or ribs}	F22B37/10	F22B37/10		156
F22B37/102	11	{Walls built-up from finned tubes}	F22B37/10	F22B37/10		205
F22B37/103	11	{Internally ribbed tubes}	F22B37/10	F22B37/10		57
F22B37/104	10	{Connection of tubes one with the other or with collectors, drums or distributors}	F22B37/10	F22B37/10		382
F22B37/105	10	{Penetrations of tubes through a wall and their sealing}	F22B37/10	F22B37/10		56
F22B37/106	10	{Studding of tubes}	F22B37/10	F22B37/10		42
F22B37/107	10	{Protection of water tubes}	F22B37/10	F22B37/10		226
F22B37/108	11	{Protection of water tube walls}	F22B37/10	F22B37/10		183
F22B37/12	10	Forms of water tubes, e.g. of varying cross-section	F22B37/12	F22B37/12		218
F22B37/125	11	{Bifurcates}	F22B37/12	F22B37/12		33
F22B37/14	10	Supply mains, e.g. rising mains, down-comers, in connection with water tubes	F22B37/14	F22B37/14		261
F22B37/141	11	{involving vertically-disposed water tubes, e.g. walls built-up from vertical tubes}	F22B37/14	F22B37/14		160
F22B37/142	11	{involving horizontally-or helically-disposed water tubes, e.g. walls built-up from horizontal or helical tubes}	F22B37/14	F22B37/14		68
F22B37/143	11	{Panel shaped heating surfaces built up from tubes (F22B37/145 takes precedence)}	F22B37/14	F22B37/14		121
F22B37/145	11	{Flag-shaped panels built-up from tubes, e.g. from U-shaped tubes}	F22B37/14	F22B37/14		31
F22B37/146	11	{Tube arrangements for ash hoppers and grates and for combustion chambers of the cyclone or similar type out of the flues}	F22B37/14	F22B37/14		151
F22B37/147	11	{Tube arrangements for cooling orifices, doors and burners}	F22B37/14	F22B37/14		45
F22B37/148	11	{Tube arrangements for the roofs}	F22B37/14	F22B37/14		23
F22B37/16	10	Return bends	F22B37/16	F22B37/16		54
F22B37/165	11	{Closures for access openings in return bends}	F22B37/16	F22B37/16		18
F22B37/18	10	Inserts, e.g. for receiving deposits from water	F22B37/18	F22B37/18		156
F22B37/20	10	Supporting arrangements, e.g. for securing water-tube sets	F22B37/20	F22B37/20		235
F22B37/201	11	{Suspension and securing arrangements for walls built-up from tubes}	F22B37/20	F22B37/20		111
F22B37/202	11	{Suspension and securing arrangements for contact heating surfaces}	F22B37/20	F22B37/20		272
F22B37/203	12	{Horizontal tubes supported only away from their ends on vertical support tubes}	F22B37/20	F22B37/20		39
F22B37/204	11	{Supporting arrangements for individual tubes, e.g. for securing tubes to a refractory wall}	F22B37/20	F22B37/20		86
F22B37/205	11	{Supporting and spacing arrangements for tubes of a tube bundle}	F22B37/20	F22B37/20		165
F22B37/206	12	{Anti-vibration supports for the bends of U-tube steam generators}	F22B37/20	F22B37/20		77
F22B37/207	11	{Supporting arrangements for drums and collectors}	F22B37/20	F22B37/20		84
F22B37/208	11	{Backstay arrangements}	F22B37/20	F22B37/20		122
F22B37/22	9	Drums; Headers; Accessories therefor	F22B37/22	F22B37/22		758
F22B37/221	10	{Covers for drums, collectors, manholes or the like}	F22B37/22	F22B37/22		161
F22B37/222	11	{Nozzle dams introduced through a smaller manway, e.g. foldable}	F22B37/22	F22B37/22		73
F22B37/223	11	{Boiler plugs, e.g. for handholes}	F22B37/22	F22B37/22		192
F22B37/225	10	{Arrangements on drums or collectors for fixing tubes or for connecting collectors to each other}	F22B37/22	F22B37/22		68
F22B37/226	10	{Protection of drums against combustion}	F22B37/22	F22B37/22		60
F22B37/227	10	{Drums and collectors for mixing}	F22B37/22	F22B37/22		42
F22B37/228	10	{Headers for distributing feedwater into steam generator vessels; Accessories therefor}	F22B37/22	F22B37/22		145
F22B37/24	9	Supporting, suspending or setting arrangements, e.g. heat shielding	F22B37/24	F22B37/24		406
F22B37/242	10	{for bottom supported water-tube steam generators}	F22B37/24	F22B37/24		65
F22B37/244	10	{for water-tube steam generators suspended from the top}	F22B37/24	F22B37/24		114
F22B37/246	10	{for steam generators of the reservoir type, e.g. nuclear steam generators}	F22B37/24	F22B37/24		25
F22B37/248	11	{with a vertical cylindrical wall}	F22B37/24	F22B37/24		49
F22B37/26	9	Steam-separating arrangements	F22B37/26	F22B37/26		815
F22B37/261	10	{specially adapted for boiler drums}	F22B37/26	F22B37/26		76
F22B37/263	10	{Valves with water separators}	F22B37/26	F22B37/26		87
F22B37/265	10	{Apparatus for washing and purifying steam}	F22B37/26	F22B37/26		457
F22B37/266	10	{Separator reheaters}	F22B37/26	F22B37/26		132
F22B37/268	10	{specially adapted for steam generators of nuclear power plants}	F22B37/26	F22B37/26		77
F22B37/28	10	involving reversal of direction of flow	F22B37/28	F22B37/28		138
F22B37/283	11	{specially adapted for boiler drums}	F22B37/28	F22B37/28		37
F22B37/286	11	{specially adapted for steam generators of nuclear power plants}	F22B37/28	F22B37/28		19
F22B37/30	10	using impingement against baffle separators	F22B37/30	F22B37/30		180
F22B37/303	11	{specially adapted for boiler drums}	F22B37/30	F22B37/30		127
F22B37/306	11	{specially adapted for steam generators of nuclear power plants}	F22B37/30	F22B37/30		21
F22B37/32	10	using centrifugal force	F22B37/32	F22B37/32		273
F22B37/322	11	{specially adapted for boiler drums}	F22B37/32	F22B37/32		115
F22B37/325	11	{using a revolving element}	F22B37/32	F22B37/32		29
F22B37/327	11	{specially adapted for steam generators of nuclear power plants}	F22B37/32	F22B37/32		60
F22B37/34	9	Adaptations of boilers for promoting water circulation (auxiliary devices for promoting water circulation F22D7/00)	F22B37/34	F22B37/34		140
F22B37/36	9	Arrangements for sheathing or casing boilers	F22B37/36	F22B37/36		320
F22B37/365	10	{Casings of metal sheets, e.g. expansion plates, expansible joints}	F22B37/36	F22B37/36		106
F22B37/38	9	Determining or indicating operating conditions in steam boilers, e.g. monitoring direction or rate of water flow through water tubes	F22B37/38	F22B37/38		625
F22B37/40	9	Arrangements of partition walls in flues of steam boilers, e.g. built-up from baffles	F22B37/40	F22B37/40		184
F22B37/42	9	Applications, arrangements or dispositions of alarm or automatic safety devices (for feed-water heaters F22D1/14{; emergency feed-water supply F22D11/003})	F22B37/42	F22B37/42		809
F22B37/421	10	{Arrangements for detecting leaks}	F22B37/42	F22B37/42		120
F22B37/423	10	{Valves for testing steam generators}	F22B37/42	F22B37/42		63
F22B37/425	10	{Feed-water supply alarm devices using floats}	F22B37/42	F22B37/42		78
F22B37/426	10	{Feed-water supply alarm devices using electric signals}	F22B37/42	F22B37/42		69
F22B37/428	10	{Feed-water supply alarm devices using dilatation of solids or liquids}	F22B37/42	F22B37/42		129
F22B37/44	10	of safety valves	F22B37/44	F22B37/44		190
F22B37/443	11	{Safety devices extinguishing the fire}	F22B37/44	F22B37/44		53
F22B37/446	11	{Safety devices responsive to overpressure}	F22B37/44	F22B37/44		306
F22B37/46	10	responsive to low or high water level, e.g. for checking, suppressing or extinguishing combustion in boilers	F22B37/46	F22B37/46		322
F22B37/47	10	responsive to abnormal temperature, e.g. actuated by fusible plugs	F22B37/47	F22B37/47		188
F22B37/475	11	{Safety devices with fusible plugs}	F22B37/47	F22B37/47		210
F22B37/48	9	Devices or arrangements for removing water, minerals or sludge from boilers (cleaning water tubes, furnace tubes or the like of boilers F28G){; Arrangement of cleaning apparatus in boilers; Combinations thereof with boilers}	F22B37/48	F22B37/48		383
F22B37/483	10	{specially adapted for nuclear steam generators}	F22B37/48	F22B37/48		296
F22B37/486	10	{Devices for removing water, minerals or sludge from boilers (F22B37/483, F22B37/50, F22B37/52 and F22B37/54 take precedence)}	F22B37/48	F22B37/48		194
F22B37/50	10	for draining or expelling water	F22B37/50	F22B37/50		378
F22B37/52	10	Washing-out devices	F22B37/52	F22B37/52		333
F22B37/54	10	De-sludging or blow-down devices {(F22B37/565 takes precedence)}	F22B37/54	F22B37/54		1272
F22B37/545	11	{Valves specially adapted therefor}	F22B37/54	F22B37/54		205
F22B37/56	9	Boiler cleaning control devices, e.g. for ascertaining proper duration of boiler blow-down	F22B37/56	F22B37/56		246
F22B37/565	10	{Blow-down control, e.g. for ascertaining proper duration of boiler blow-down}	F22B37/56	F22B37/56		152
F22B37/58	9	Removing tubes from headers or drums; Extracting tools	F22B37/58	F22B37/58		45
F22B37/60	8	specially adapted for steam boilers of instantaneous or flash type	F22B37/60	F22B37/60		23
F22B37/62	8	specially adapted for steam boilers of forced-flow type	F22B37/62	F22B37/62		15
F22B37/64	9	Mounting of, or supporting arrangements for, tube units	F22B37/64	F22B37/64		41
F22B37/645	10	{involving upper vertically-disposed water tubes and lower horizontally- or helically disposed water tubes}	F22B37/64	F22B37/64		25
F22B37/66	10	involving vertically-disposed water tubes {(F22B37/645 takes precedence)}	F22B37/66	F22B37/66		43
F22B37/68	10	involving horizontally-disposed water tubes {(F22B37/645 takes precedence)}	F22B37/68	F22B37/68		41
F22B37/70	9	Arrangements for distributing water into water tubes	F22B37/70	F22B37/70		51
F22B37/72	10	involving injection devices	F22B37/72	F22B37/72		13
F22B37/74	10	Throttling arrangements for tubes or sets of tubes	F22B37/74	F22B37/74		68
F22B37/76	8	Adaptations or mounting of devices for observing existence or direction of fluid flow	F22B37/76	F22B37/76		24
F22B37/78	8	Adaptations or mounting of level indicators	F22B37/78	F22B37/78		909
