F22BMETHODS OF STEAM GENERATIONSTEAM BOILERS steam engine plants where engine aspects predominate F01K; domestic central-heating systems using steam F24D; heat exchange or heat transfer in general F28; generation of vapour in the cores of nuclear reactors G21This subclass covers only methods of, or apparatus for, the generation of steam under pressure for heating or power purposesIn this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme. F22B1/00General aspects of, or methods for, steam generation F22B1/00Methods of steam generation characterised by form of heating method solar heating F24S; jackets or other cooling means in which steam is generated and which serve for cooling other apparatus, see the subclasses for such apparatus F22B1/003using combustion of hydrogen with oxygen power plants using steam created by combustion of hydrogen with oxygen F01K25/005 F22B1/006using solar heat solar heat collectors per se F24S; devices for producing mechanical power from solar energy F03G6/00 F22B1/02by exploitation of the heat content of hot heat carriers F22B1/021with heating tubes in which flows a non-specified heating fluid for nuclear reactors F22B1/023, for hot gas F22B1/1884 F22B1/023with heating tubes, for nuclear reactors as far as they are not classified, according to a specified heating fluid, in another group F22B1/025with vertical U shaped tubes carried on a horizontal tube sheet F22B1/026with vertical tubes between to horizontal tube sheets F22B1/028Steam generation using heat accumulators F22B27/14 takes precedence F22B1/04the heat carrier being hot slag, hot residues, or heated blocks, e.g. iron blocks F22B1/06the heat carrier being moltenUse of molten metal, e.g. zinc, as heat transfer medium F22B1/063for metal cooled nuclear reactors heat-exchangers having a liquid metal as heat exchange medium F28D7/00C F22B1/066with double-wall tubes having a third fluid between these walls, e.g. helium for leak detection heat-exchangers with double-wall tubes F28D7/10; double-wall pipes per se F16L9/18 F22B1/08the heat carrier being steam F22B1/10released from heat accumulators F22B1/12produced by an indirect cyclic process F22B1/123Steam generators downstream of a nuclear boiling water reactor F22B1/126Steam generators of the Schmidt-Hartmann type F22B1/14coming in direct contact with water in bulk or in sprays F22B1/143in combination with a nuclear installation F22B1/146Loffler boilers F22B1/16the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour F22B1/162in combination with a nuclear installation F22B1/165using heat pipes heat pipes per se F28D15/02 F22B1/167using an organic fluid F22B1/18the 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, F02G F22B1/1807using the exhaust gases of combustion engines F22B1/1815using the exhaust gases of gas-turbines F22B1/1823for gas-cooled nuclear reactors F22B1/183in combination with metallurgical converter installations F22B1/1838the hot gas being under a high pressure, e.g. in chemical installations F22B1/1846the hot gas being loaded with particles, e.g. waste heat boilers after a coal gasification plant F22B1/1853coming in direct contact with water in bulk or in sprays F22B1/1861Waste heat boilers with supplementary firing F22B1/1869Hot gas water tube boilers not provided for in F22B1/1807 - F22B1/1861 F22B1/1876the hot gas being loaded with particles, e.g. dust with the hot gas being under high pressure F22B1/1846 F22B1/1884Hot gas heating tube boilers with one or more heating tubes F22B1/1892Systems therefor not provided for in F22B1/1807 - F22B1/1861 F22B1/20using heat evolved in a solution absorbing steamSoda steam boilers F22B1/22using combustion under pressure substantially exceeding atmospheric pressure F22B1/24Pressure-fired steam boilers, e.g. using turbo-air compressors actuated by hot gases from boiler furnace F22B1/26Steam boilers of submerged-flame type, i.e. the flame being surrounded by, or impinging on, the water to be vaporised , e.g. water in sprays F22B1/265the water being in bulk F22B1/28in boilers heated electrically superheating using an electrical heat source independent from heat supply of the steam boiler F22G1/165 F22B1/281other than by electrical resistances or electrodes F22B1/282with water or steam circulating in tubes or ducts F22B1/284with water in reservoirs F22B1/285the water being fed by a pump to the reservoirs F22B1/287with water in sprays or in films F22B1/288Instantaneous electrical steam generators built-up from heat-exchange elements arranged within a confined chamber having heat-retaining walls F22B1/30Electrode boilers F22B1/303with means for injecting or spraying water against electrodes or with means for water circulation F22B1/306with at least one electrode permanently above the water surface F22B3/00Other methods of steam generationSteam boilers not provided for in other groups of this subclass F22B3/02involving the use of working media other than water F22B3/04by drop in pressure of high-pressure hot water within pressure- reducing chambers, e.g. in accumulators steam accumulators per se F01K1/00 F22B3/045the drop in pressure being achieved by compressors, e.g. with steam jet pumps F22B3/06by transformation of mechanical, e.g. kinetic, energy into heat energy F22B3/08at critical or supercritical pressure values F22B5/00Kinds of steam boilers F22B5/00Steam boilers of drum type, i.e. without internal furnace or fire tubes, the boiler body being contacted externally by flue gas F22B5/005with rotating drums F22B5/02with auxiliary water tubes outside the boiler body F22B5/04Component parts thereofAccessories therefor covers or similar closure members F16J13/00 F22B7/00Steam 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 F22B7/02without auxiliary water tubes F22B7/04with auxiliary water tubes F22B7/06inside the furnace tube in transverse arrangements F22B7/08inside the furnace tube in longitudinal arrangement F22B7/10outside the boiler body F22B7/12with auxiliary fire tubesArrangement of header boxes providing for return diversion of flue gas flow F22B7/14with both auxiliary water tubes and auxiliary fire tubes F22B7/16Component parts thereofAccessories therefor, e.g. stay-bolt connections F22B7/18Walling of fluesFlue gas header boxes F22B7/20Furnace tubes F22B9/00Steam 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 F22B9/02the boiler body being disposed upright, e.g. above the combustion chamber F22B9/04the fire tubes being in upright arrangement F22B9/06Arrangement of header boxes providing for return diversion of flue gas flow F22B9/08the fire tubes being in horizontal arrangement F22B9/10the boiler body being disposed substantially horizontally, e.g. at the side of the combustion chamber F22B9/12the fire tubes being in substantially horizontal arrangement F22B9/14Arrangement of header boxes providing for return diversion of flue gas flow F22B9/16the boiler body containing fire tubes disposed crosswise in inclined upward arrangement F22B9/18Component parts thereofAccessories therefor, e.g. stay-bolt connections F22B11/00Steam boilers of combined fire-tube type and water-tube type, i.e. steam boilers of fire-tube type having auxiliary water tubes F22B11/02the fire tubes being in upright arrangement F22B11/04the fire tubes being in horizontal arrangement F22B13/00Steam 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 F22B13/005with flues, other than fire tubes F22B13/02mounted in fixed position with the boiler body disposed upright F22B13/023with auxiliary water tubes inside the fire-box, e.g. vertical tubes F22B13/10 takes precedence F22B13/026the tubes being in substantially horizontal arrangement F22B13/04mounted in fixed position with the boiler body disposed substantially horizontally F22B13/06Locomobile, traction-engine, steam-roller, or locomotive boilers F22B13/065Combination of low and high pressure locomotive boilers F22B13/08without auxiliary water tubes inside the fire-box F22B13/10with auxiliary water tubes inside the fire-box F22B13/12the auxiliary water tubes lining the fire-box F22B13/14Component parts thereofAccessories therefor F22B13/145Firebox thermosiphons F22B13/16Stay-bolt connections, e.g. rigid connections F22B13/18Flexible connections, e.g. of ball-and-socket type F22B15/00Water-tube boilers of horizontal type, i.e. the water-tube sets being arranged horizontally F22B17/00Water-tube boilers of horizontally-inclined type, e.g. the water-tube sets being inclined slightly with respect to the horizontal plane F22B17/02built-up from water-tube sets in abutting connection with two header boxes in common for all sets, e.g. with flat header boxes F22B17/025with combined inlet and outlet header boxes, e.g. connected by U-tubes or Field tubes F22B17/04the water-tube sets being inclined in opposite directions, e.g. crosswise F22B17/06the water-tube sets being bent angularly F22B17/08the water-tube sets being curved F22B17/10built-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 F22B17/105with tubes in series flow arrangement F22B17/12the sectional headers being in vertical or substantially vertical arrangement F22B17/14the sectional headers being in horizontal or substantially horizontal arrangement F22B17/16Component parts thereofAccessories therefor F22B17/18Header boxesSectional headers F22B19/00Water-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 F22B21/00Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically F22B21/002involving a single upper drum F22B21/36 takes precedence F22B21/005involving a central vertical drum, header or downcomer F22B21/007specially adapted for locomotives F22B21/02built-up from substantially straight water tubes F22B21/04involving a single upper drum and a single lower drum, e.g. the drums being arranged transversely F22B21/06the water tubes being arranged annularly in sets, e.g. in abutting connection with drums of annular shape F22B21/065involving an upper and lower drum of annular shape F22B21/08the water tubes being arranged sectionally in groups or in banks, e.g. bent over at their ends F22B21/081involving a combustion chamber, placed at the side and built-up from water tubes F22B21/083involving an upper drum and a lower drum and a fire-place between the two drums F22B21/085the tubes being placed in layers F22B21/086Frames built-up from water tubes F22B21/088involving an upper drum and a lower drum and two lateral drums F22B21/10the water tubes being arranged in staggered rows F22B21/12involving two or more upper drums and two or more lower drums, e.g. with crosswise-arranged water-tube sets in abutting connections with drums F22B21/123involving crossed water tubes F22B21/126involving more than two lower or upper drums F22B21/14involving a single upper drum and two or more lower drums F22B21/16the lower drums being interconnected by further water tubes F22B21/18involving two or more upper drums and a single lower drum F22B21/185involving more than two upper drums and a single lower drum F22B21/20involving sectional or subdivided headers in separate arrangement for each water-tube set F22B21/22built-up from water tubes of form other than straight or substantially straight F22B21/24bent in serpentine or sinuous form F22B21/26bent helically, i.e. coiled F22B21/28bent spirally F22B21/30bent in U-loop form F22B21/32disposed horizontally in abutting connection with upright headers or rising water mains F22B21/34built-up from water tubes grouped in panel form surrounding the combustion chamber, i.e. radiation boilers F22B21/341Vertical radiation boilers with combustion in the lower part F22B21/343the vertical radiation combustion chamber being connected at its upper part to a sidewards convection chamber F22B21/345with a tube bundle between an upper and a lower drum in the convection pass F22B21/346Horizontal radiation boilers F22B21/348Radiation boilers with a burner at the top F22B21/36involving an upper drum or headers mounted at the top of the combustion chamber F22B21/363involving a horizontal drum mounted in an upper corner of the boiler F22B21/366involving a horizontal drum mounted in the middle of the boiler F22B21/38Component parts thereof, e.g. prefabricated panels F22B21/40built-up from water tubes arranged in a comparatively long vertical shaft, i.e. tower boilers F22B23/00Water-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 F22B23/02the water-tube, i.e. Field-tube, sets being horizontal or substantially horizontal F22B23/04the water-tube, i.e. Field-tube, sets being vertical or substantially vertical F22B23/06Component parts thereof, e.g. Field water tubes heat-exchange tubes in general F28F F22B25/00Water-tube boilers built-up from sets of water tubes with internally-arranged flue tubes, or fire tubes, extending through the water tubes F22B27/00Instantaneous or flash steam boilers F22B27/02built-up from fire tubes F22B27/04built-up from water tubes F22B27/12 - F22B27/16 take precedence F22B27/06bent in serpentine or sinuous form F22B27/08bent helically, i.e. coiled F22B27/10bent spirally F22B27/12built-up from rotary heat-exchange elements, e.g. from tube assemblies F22B27/14built-up from heat-exchange elements arranged within a confined chamber having heat-retaining walls F22B1/288 takes precedence F22B27/16involving spray nozzles for sprinkling or injecting water particles on to or into hot heat-exchange elements, e.g. into tubes F22B1/287 takes precedence F22B27/165with film flow of water on heated surfaces F22B29/00Steam boilers of forced-flow type F22B29/02of forced-circulation type F22B29/06 takes precedence F22B29/023without drums, i.e. without hot water storage in the boiler F22B29/026operating at critical or supercritical pressure F22B29/04of 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 F22B29/06of 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 F22B33/00 takes precedence F22B29/061Construction of tube walls F22B29/062involving vertically-disposed water tubes F22B29/064involving horizontally- or helically-disposed water tubes F22B29/065involving upper vertically disposed water tubes and lower horizontally- or helically disposed water tubes F22B29/067operating at critical or supercritical pressure with recirculation during normal operation F22B29/026 F22B29/068operating with superimposed recirculation during normal operation F22B29/12 takes precedence F22B29/08operating with fixed point of final state of complete evaporation evaporation or evaporation apparatus for physical or chemical purposes, e.g. evaporation of liquids for gas phase reactions B01B1/005 F22B29/10operating with sliding point of final state of complete evaporation evaporation or evaporation apparatus for physical or chemical purposes, e.g. evaporation of liquids for gas phase reactions B01B1/005 F22B29/12operating with superimposed recirculation during starting and low-load periods, e.g. composite boilers F22B31/00Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatusArrangements of dispositions of combustion apparatus steam generation characterised by heating method F22B1/00; combustion apparatus per se F23 F22B31/0007with combustion in a fluidized bed fluidized bed apparatus per se B01J8/00; fluidized bed combustors F23C10/00 F22B31/0015for boilers of the water tube type F22B31/0023with tubes in the bed F22B31/003 takes precedence F22B31/003with tubes surrounding the bed or with water tube wall partitions F22B31/0038with tubes in the bed F22B31/0046for boilers of the shell type, e.g. with furnace box F22B31/0053with auxiliary water tubes F22B31/0061Constructional features of bed cooling F22B31/0069Systems therefor F22B31/0076Controlling processes for fluidized bed boilers not related to a particular type F22B31/0084with recirculation of separated solids or with cooling of the bed particles outside the combustion bed F22B31/0092with a fluidized heat exchange bed and a fluidized combustion bed separated by a partition, the bed particles circulating around or through that partition F22B31/02Installation of water-tube boilers in chimneys, e.g. in converter chimneys F22B31/04Heat supply by installation of two or more combustion apparatus, e.g. of separate combustion apparatus for the boiler and the superheater respectively F22B31/045Steam generators specially adapted for burning refuse F22B31/06Installation of emergency heat supply F22B31/08Installation of heat-exchange apparatus or of means in boilers for heating air supplied for combustion F22B33/00Steam-generation plantsControl systems F22B33/00Steam-generation plants, e.g. comprising steam boilers of different types in mutual association arrangements or dispositions of steam-generation plants in marine vessels B63H21/00 F22B33/02Combinations of boilers having a single combustion apparatus in common F22B33/04of boilers of furnace-tube type with boilers of water-tube type F22B33/06of boilers of furnace-tube type with boilers of fire-tube type F22B33/08of boilers of water tube type with boilers of fire-tube type F22B33/10of two or more superposed boilers with separate water volumes and operating with two or more separate water levels F22B33/12Self-contained steam boilers, i.e. comprising as a unit the steam boiler, the combustion apparatus, the fuel storage, accessory machines and equipment F22B33/14Combinations of low and high pressure boilers F22B13/065 takes precedence F22B33/16of forced-flow type F22B33/18Combinations of steam boilers with other apparatus F22B33/185in combination with a steam accumulator F22B35/00Control systems for steam boilers for fluidized bed boilers F22B31/0076; regulation or control of steam power plants F01K7/00; for regulating feed-water supply F22D; for controlling superheat temperature F22G5/00; control of combustion F23N; regulating or controlling in general G05 F22B35/001Controlling by flue gas dampers for superheaters F22G5/04 F22B35/002Control by recirculating flue gases for superheaters F22G5/06 F22B35/004Control systems for steam generators of nuclear power plants F22B35/005Control systems for instantaneous steam boilers F22B35/007Control systems for waste heat boilers F22B35/008Control systems for two or more steam generators F22D5/36 takes precedence F22B35/02for steam boilers with natural convection circulation F22B35/04during 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 F22B35/06for steam boilers of forced-flow type F22B35/08of forced-circulation type F22B35/083without drum, i.e. without hot water storage in the boiler F22B35/086operating at critical or supercritical pressure F22B35/10of once-through type F22B35/101operating with superimposed recirculation during starting or low load periods, e.g. composite boilers F22B35/125 takes precedence F22B35/102operating with fixed point of final state of complete evaporation, e.g. in a steam-water separator F22B35/104Control systems by injecting water for superheaters F22G5/12 F22B35/105operating at sliding pressure F22B35/107Control systems with auxiliary heating surfaces F22B35/108Control systems for steam generators having multiple flow paths F22B35/12operating at critical or supercritical pressure F22B35/125operating with superimposed recirculation during starting or low load periods, e.g. composite boilers F22B35/14during 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 F22B35/16responsive to the percentage of steam in the mixture of steam and water F22B35/18Applications of computers to steam boiler control F22B37/00Component parts or details of steam boilers venting devices F16K24/00; steam traps or like apparatus F16T F22B37/001Steam generators built-up from pre-fabricated elements F22B37/002specially adapted for nuclear steam generators, e.g. maintenance, repairing or inspecting equipment not otherwise provided for F22B37/003Maintenance, repairing or inspecting equipment positioned in or via the headers F22B37/005Positioning apparatus specially adapted therefor F22B37/64 takes precedence F22B37/006Walking equipment, e.g. walking platforms suspended at the tube sheet walking mechanism per se B62D57/02 F22B37/007Installation or removal of nuclear steam generators F22B37/008Adaptations for flue gas purification in steam generators, flue gas purification in general F23J; gas purification in general B01D F22B37/02applicable to more than one kind or type of steam boiler F22B37/025Devices and methods for diminishing corrosion, e.g. by preventing cooling beneath the dew point F22B37/04and characterised by material, e.g. use of special steel alloy F22B37/06Flue or fire tubesAccessories therefor, e.g. fire-tube inserts F22B37/08Fittings preventing burning-off of the tube edges F22B37/10Water tubesAccessories therefor working of metal tubes B21D; pipes in general F16L; repairing leaks in water tubes F16L55/16; F28F11/00; baffles, screens, or deflectors formed of water tubes F23M9/10; cleaning internal or external surfaces of water tubes F28G F22B37/101Tubes having fins or ribs F22B37/102Walls built-up from finned tubes F22B37/103Internally ribbed tubes F22B37/104Connection of tubes one with the other or with collectors, drums or distributors in general F16L F22B37/105Penetrations of tubes through a wall and their sealing in general F16L5/00 F22B37/106Studding of tubes F22B37/107Protection of water tubes in general F16L57/00 F22B37/108Protection of water tube walls F22B37/12Forms of water tubes, e.g. of varying cross-section F22B37/125Bifurcates F22B37/14Supply mains, e.g. rising mains, down-comers, in connection with water tubes F22B37/141involving vertically-disposed water tubes, e.g. walls built-up from vertical tubes F22B37/142involving horizontally-or helically-disposed water tubes, e.g. walls built-up from horizontal or helical tubes F22B37/143Panel shaped heating surfaces built up from tubes F22B37/145 takes precedence F22B37/145Flag-shaped panels built-up from tubes, e.g. from U-shaped tubes F22B37/146Tube arrangements for ash hoppers and grates and for combustion chambers of the cyclone or similar type out of the flues F22B37/147Tube arrangements for cooling orifices, doors and burners F22B37/148Tube arrangements for the roofs F22B37/16Return bends F22B37/165Closures for access openings in return bends boiler plugs for drums or headers F22B37/223 F22B37/18Inserts, e.g. for receiving deposits from water F22B37/20Supporting arrangements, e.g. for securing water-tube sets construction of tube walls of furnaces including boiler furnaces F23M5/08 F22B37/201Suspension and securing arrangements for walls built-up from tubes F22B37/202Suspension and securing arrangements for contact heating surfaces F22B37/203Horizontal tubes supported only away from their ends on vertical support tubes F22B37/204Supporting arrangements for individual tubes, e.g. for securing tubes to a refractory wall F22B37/205Supporting and spacing arrangements for tubes of a tube bundle F22B37/206Anti-vibration supports for the bends of U-tube steam generators F22B37/207Supporting arrangements for drums and collectors F22B37/208Backstay arrangements F22B37/22DrumsHeadersAccessories therefor making boilers from sheet metal B21D51/24; pressure vessels in general F16J12/00; covers or similar closure members F16J13/00 F22B37/221Covers for drums, collectors, manholes or the like in general F16J13/00 F22B37/222Nozzle dams introduced through a smaller manway, e.g. foldable F22B37/223Boiler plugs, e.g. for handholes closures for access openings in return bends F22B37/165 F22B37/225Arrangements on drums or collectors for fixing tubes or for connecting collectors to each other F22B37/226Protection of drums against combustion F22B37/227Drums and collectors for mixing F22B37/228Headers for distributing feedwater into steam generator vessels; Accessories therefor F22B37/24Supporting, suspending, or setting arrangements, e.g. heat shielding frames, engine beds F16M F22B37/242for bottom supported water-tube steam generators F22B37/244for water-tube steam generators suspended from the top F22B37/246for steam generators of the reservoir type, e.g. nuclear steam generators F22B37/248with a vertical cylindrical wall F22B37/26Steam-separating arrangements vapour-liquid separators, e.g. for drying steam, B01D; B04 F22B37/261specially adapted for boiler drums F22B37/263Valves with water separators F22B37/265Apparatus for washing and purifying steam F22B37/266Separator reheaters F22B37/268specially adapted for steam generators of nuclear power plants F22B37/28involving reversal of direction of flow F22B37/283specially adapted for boiler drums F22B37/286specially adapted for steam generators of nuclear power plants F22B37/30using impingement against baffle separators F22B37/303specially adapted for boiler drums F22B37/306specially adapted for steam generators of nuclear power plants F22B37/32using centrifugal force F22B37/322specially adapted for boiler drums F22B37/325using a revolving element F22B37/327specially adapted for steam generators of nuclear power plants F22B37/34Adaptations of boilers for promoting water circulation F22B13/145 takes precedence ; auxiliary devices for promoting water circulation F22D7/00 F22B37/36Arrangements for sheathing or casing boilers F22B37/365Casings of metal sheets, e.g. expansion plates, expansible joints F22B37/38Determining 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 G01 F22B37/40Arrangements of partition walls in flues of steam boilers, e.g. built-up from baffles in flues or chimneys F23J13/00 F22B37/42Applications, arrangements, or dispositions of alarm or automatic safety devices for feed-water heaters F22D1/14 ; emergency feed-water supply F22D11/003; alarms responsive to undesired or abnormal conditions G08B F22B37/421Arrangements for detecting leaks F22B37/423Valves for testing steam generators F22B37/425Feed-water supply alarm devices using floats F22B37/426Feed-water supply alarm devices using electric signals F22B37/428Feed-water supply alarm devices using dilatation of solids or liquids F22B37/44of safety valves safety valves per se F16K F22B37/443Safety devices extinguishing the fire F22B37/446Safety devices responsive to overpressure F22B37/46responsive to low or high water level, e.g. for checking, suppressing, extinguishing combustion in boilers fire-fighting, fire extinction in general A62 F22B37/47responsive to abnormal temperature, e.g. actuated by fusible plugs such alarms or devices per se G08B F22B37/475Safety devices with fusible plugs F22B37/48Devices for removing water, salt, or sludge from boilers cleaning internal or external surfaces of water tubes F28GArrangements of cleaning apparatus in boilers cleaning external surfaces of tubes by soot blowers F23JCombinations thereof with boilers F22B37/483specially adapted for nuclear steam generators F22B37/486Devices for removing water, salt, or sludge from boilers F22B37/483, F22B37/50, F22B37/52 and F22B37/54 take precedence F22B37/50for draining or expelling water F22B37/52Washing-out devices F22B37/54De-sludging or blow-down devices F22B37/565 takes precedence F22B37/545Valves specially adapted therefor valves in general F16K F22B37/56Boiler cleaning control devices, e.g. for ascertaining proper duration of boiler blow-down F22B37/565Blow-down control, e.g. for ascertaining proper duration of boiler blow-down F22B37/58Removing tubes from headers or drumsExtracting tools F22B37/60specially adapted for steam boilers of instantaneous or flash type F22B37/62specially adapted for steam boilers of forced-flow type F22B37/64Mounting of, or supporting arrangements for, tube units construction of tube walls of furnaces, e.g. boiler furnaces F23M5/08 F22B37/645involving upper vertically-disposed water tubes and lower horizontally- or helically disposed water tubes F22B37/66involving vertically-disposed water tubes F22B37/645 takes precedence F22B37/68involving horizontally-disposed water tubes F22B37/645 takes precedence F22B37/70Arrangements for distributing water into water tubes F22B37/72involving injection devices F22B37/74Throttling arrangements for tubes or sets of tubes F22B37/76Adaptations or mounting of devices for observing existence or direction of fluid flow devices per se G01P F22B37/78Adaptations or mounting of level indicators level indicators per se G01F