IPC Classification

Class code (prefix) Descriptions Number of results
F22B 1/00 Methods of steam generation characterised by form of heating method
F22B 1/02 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
F22B 1/04 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot slag, hot residues, or heated blocks, e.g. iron blocks
F22B 1/06 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being molten; Use of molten metal, e.g. zinc, as heat transfer medium
F22B 1/08 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being steam
F22B 1/10 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being steam released from heat accumulators
F22B 1/12 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being steam produced by an indirect cyclic process
F22B 1/14 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being steam coming in direct contact with water in bulk or in sprays
F22B 1/16 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour
F22B 1/18 Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines
F22B 1/20 Methods of steam generation characterised by form of heating method using heat evolved in a solution absorbing steam; Soda steam boilers
F22B 1/22 Methods of steam generation characterised by form of heating method 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 Methods of steam generation characterised by form of heating method in boilers heated electrically
F22B 1/30 Electrode boilers
F22B 3/00 Other methods of steam generation; Steam boilers not provided for in other groups of this subclass
F22B 3/02 Other methods of steam generation; Steam boilers not provided for in other groups of this subclass involving the use of working media other than water
F22B 3/04 Other methods of steam generation; Steam boilers not provided for in other groups of this subclass by drop in pressure of high-pressure hot water within pressure-reducing chambers, e.g. in accumulators
F22B 3/06 Other methods of steam generation; Steam boilers not provided for in other groups of this subclass by transformation of mechanical, e.g. kinetic, energy into heat energy
F22B 3/08 Other methods of steam generation; Steam boilers not provided for in other groups of this subclass at critical or supercritical pressure values
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 Steam boilers of drum type, i.e. without internal furnace or fire tubes, the boiler body being contacted externally by flue gas with auxiliary water tubes outside the boiler body
F22B 5/04 Component parts thereof; Accessories therefor
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 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 without auxiliary water tubes
F22B 7/04 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 with auxiliary water tubes
F22B 7/06 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 with auxiliary water tubes inside the furnace tube in transverse arrangement
F22B 7/08 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 with auxiliary water tubes inside the furnace tube in longitudinal arrangement
F22B 7/10 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 with auxiliary water tubes outside the boiler body
F22B 7/12 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 with auxiliary fire tubes; Arrangement of header boxes providing for return diversion of flue gas flow
F22B 7/14 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 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
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 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 the boiler body being disposed upright, e.g. above the combustion chamber
F22B 9/04 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 the boiler body being disposed upright, e.g. above the combustion chamber 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 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 the boiler body being disposed upright, e.g. above the combustion chamber the fire tubes being in horizontal arrangement
F22B 9/10 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 the boiler body being disposed substantially horizontally, e.g. at the side of the combustion chamber
F22B 9/12 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 the boiler body being disposed substantially horizontally, e.g. at the side of the combustion chamber 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 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 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
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 Steam boilers of combined fire-tube type and water-tube type, i.e. steam boilers of fire-tube type having auxiliary water tubes the fire tubes being in upright arrangement
F22B 11/04 Steam boilers of combined fire-tube type and water-tube type, i.e. steam boilers of fire-tube type having auxiliary water tubes the fire tubes being in horizontal arrangement
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 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 mounted in fixed position with the boiler body disposed upright
F22B 13/04 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 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 Locomobile, traction-engine, steam-roller, or locomotive boilers without auxiliary water tubes inside the fire-box
F22B 13/10 Locomobile, traction-engine, steam-roller, or locomotive boilers with auxiliary water tubes inside the fire-box
F22B 13/12 Locomobile, traction-engine, steam-roller, or locomotive boilers with auxiliary water tubes inside the fire-box 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
F22B 15/00 Water-tube boilers of horizontal type, i.e. the water-tube sets being arranged horizontally
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 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane 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 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane built-up from water-tube sets in abutting connection with two header boxes in common for all sets, e.g. with flat header boxes the water-tube sets being inclined in opposite directions, e.g. crosswise
F22B 17/06 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane built-up from water-tube sets in abutting connection with two header boxes in common for all sets, e.g. with flat header boxes the water-tube sets being bent angularly
F22B 17/08 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane built-up from water-tube sets in abutting connection with two header boxes in common for all sets, e.g. with flat header boxes the water-tube sets being curved
F22B 17/10 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane 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 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane 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 the sectional headers being in vertical or substantially-vertical arrangement
F22B 17/14 Water-tube boilers of horizontally-inclined type, i.e. the water-tube sets being inclined slightly with respect to the horizontal plane 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 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
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
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 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes
F22B 21/04 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely
F22B 21/06 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely the water tubes being arranged annularly in sets, e.g. in abutting connection with drums of annular shape
F22B 21/08 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely the water tubes being arranged sectionally in groups or in banks, e.g. bent over at their ends
F22B 21/10 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely the water tubes being arranged in staggered rows
F22B 21/12 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes 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 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving a single upper drum and two or more lower drums
F22B 21/16 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving a single upper drum and two or more lower drums the lower drums being interconnected by further water tubes
F22B 21/18 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving two or more upper drums and a single lower drum
F22B 21/20 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from substantially-straight water tubes involving sectional or subdivided headers in separate arrangement for each water-tube set
F22B 21/22 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes of form other than straight or substantially straight
F22B 21/24 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes of form other than straight or substantially straight bent in serpentine or sinuous form
F22B 21/26 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes of form other than straight or substantially straight bent helically, i.e. coiled
F22B 21/28 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes of form other than straight or substantially straight bent spirally
F22B 21/30 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes of form other than straight or substantially straight bent in U-loop form
F22B 21/32 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes of form other than straight or substantially straight bent in U-loop form disposed horizontally in abutting connection with upright headers or rising water mains
F22B 21/34 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes grouped in panel form surrounding the combustion chamber, i.e. radiation boilers
F22B 21/36 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes grouped in panel form surrounding the combustion chamber, i.e. radiation boilers 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 Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes arranged in a comparatively long vertical shaft, i.e. tower boilers
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 oute
F22B 23/02 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 oute the water-tube, i.e. Field-tube, sets being horizontal or substantially horizontal
F22B 23/04 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 oute the water-tube, i.e. Field-tube, sets being vertical or substantially vertical
F22B 23/06 Component parts thereof, e.g. Field water tubes
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
F22B 27/00 Instantaneous or flash steam boilers
F22B 27/02 Instantaneous or flash steam boilers built-up from fire tubes
F22B 27/04 Instantaneous or flash steam boilers built-up from water tubes
F22B 27/06 Instantaneous or flash steam boilers built-up from water tubes bent in serpentine or sinuous form
F22B 27/08 Instantaneous or flash steam boilers built-up from water tubes bent helically, i.e. coiled
F22B 27/10 Instantaneous or flash steam boilers built-up from water tubes bent spirally
F22B 27/12 Instantaneous or flash steam boilers built-up from rotary heat-exchange elements, e.g. from tube assemblies
F22B 27/14 Instantaneous or flash steam boilers built-up from heat-exchange elements arranged within a confined chamber having heat-retaining walls
F22B 27/16 Instantaneous or flash steam boilers involving spray nozzles for sprinkling or injecting water particles on to or into hot heat-exchange elements, e.g. into tubes
F22B 29/00 Steam boilers of forced-flow type
F22B 29/02 Steam boilers of forced-flow type of forced-circulation type
F22B 29/04 Steam boilers of forced-flow type 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 Steam boilers of forced-flow type 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
F22B 29/08 Steam boilers of forced-flow type 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 operating with fixed point of final state of complete evaporation
F22B 29/10 Steam boilers of forced-flow type 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 operating with sliding point of final state of complete evaporation
F22B 29/12 Steam boilers of forced-flow type 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 operating with superimposed recirculation during starting and low-load periods, e.g. composite boilers
F22B 31/00 Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements or dispositions of combustion apparatus
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 Steam-generation plants, e.g. comprising steam boilers of different types in mutual association
F22B 33/02 Combinations of boilers having a single combustion apparatus in common
F22B 33/04 Combinations of boilers having a single combustion apparatus in common of boilers of furnace-tube type with boilers of water-tube type
F22B 33/06 Combinations of boilers having a single combustion apparatus in common of boilers of furnace-tube type with boilers of fire-tube type
F22B 33/08 Combinations of boilers having a single combustion apparatus in common of boilers of water-tube type with boilers of fire-tube type
F22B 33/10 Combinations of boilers having a single combustion apparatus in common 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 Combinations of low- and high-pressure boilers of forced-flow type
F22B 33/18 Combinations of steam boilers with other apparatus
F22B 35/00 Control systems for steam boilers
F22B 35/02 Control systems for steam boilers for steam boilers with natural convection circulation
F22B 35/04 Control systems for steam boilers for steam boilers with natural convection circulation 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 Control systems for steam boilers for steam boilers of forced-flow type
F22B 35/08 Control systems for steam boilers for steam boilers of forced-flow type of forced-circulation type
F22B 35/10 Control systems for steam boilers for steam boilers of forced-flow type of once-through type
F22B 35/12 Control systems for steam boilers for steam boilers of forced-flow type of once-through type operating at critical or supercritical pressure
F22B 35/14 Control systems for steam boilers for steam boilers of forced-flow type 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 Control systems for steam boilers for steam boilers of forced-flow type responsive to the percentage of steam in the mixture of steam and water
F22B 35/18 Applications of computers to steam-boiler control
F22B 37/00 Component parts or details of steam boilers
F22B 37/02 Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
F22B 37/04 Component parts or details of steam boilers applicable to more than one kind or type of steam boiler 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
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
F22B 37/22 Drums; Headers; Accessories therefor
F22B 37/24 Supporting, suspending, or setting arrangements, e.g. heat shielding
F22B 37/26 Steam-separating arrangements
F22B 37/28 Steam-separating arrangements involving reversal of direction of flow
F22B 37/30 Steam-separating arrangements using impingement against baffle separators
F22B 37/32 Steam-separating arrangements using centrifugal force
F22B 37/34 Adaptations of boilers for promoting water circulation
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
F22B 37/40 Arrangements of partition walls in flues of steam boilers, e.g. built-up from baffles
F22B 37/42 Applications, arrangements, or dispositions of alarm or automatic safety devices
F22B 37/44 Applications, arrangements, or dispositions of alarm or automatic safety devices of safety valves
F22B 37/46 Applications, arrangements, or dispositions of alarm or automatic safety devices responsive to low or high water level, e.g. for checking, suppressing, extinguishing combustion in boilers
F22B 37/47 Applications, arrangements, or dispositions of alarm or automatic safety devices responsive to abnormal temperature, e.g. actuated by fusible plugs
F22B 37/48 Devices or arrangements for removing water, minerals, or sludge from boilers
F22B 37/50 Devices or arrangements for removing water, minerals, or sludge from boilers 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 Component parts or details of steam boilers specially adapted for steam boilers of instantaneous or flash type
F22B 37/62 Component parts or details of steam boilers specially adapted for steam boilers of forced-flow type
F22B 37/64 Mounting of, or supporting arrangements for, tube units
F22B 37/66 Mounting of, or supporting arrangements for, tube units involving vertically-disposed water tubes
F22B 37/68 Mounting of, or supporting arrangements for, tube units involving horizontally-disposed water tubes
F22B 37/70 Arrangements for distributing water into water tubes
F22B 37/72 Arrangements for distributing water into water tubes 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
F22B 37/78 Adaptations or mounting of level indicators