F28G CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS (cleaning pipes or tubes in general B08B9/02; devices or arrangements for removing water, minerals, or sludge from boilers while the boiler is in operation, or which remain in position while the boiler is in operation, or are specifically adapted to boilers without any other utility F22B37/48; removal or treatment of combustion products or combustion residues F23J; removing ice from heat-exchange apparatus F28F17/00)
Introduced: September 1968
Description
F28G covers apparatus and methods for removing fouling, scale, deposits, and other contaminants from the interior or exterior surfaces of heat-exchange conduits, including boiler tubes, pipes, and similar thermal transfer systems. This classification encompasses mechanical cleaning devices (brushes, scrapers, sponge balls), chemical cleaning processes, and combined approaches designed to maintain heat transfer efficiency and system integrity. It applies to both in-service cleaning operations and maintenance procedures for industrial heat exchangers, steam generators, and related equipment. Adjacent classes F28D (heat exchangers) and F22B (steam generation) address the heat-exchange devices themselves, while F28G focuses specifically on their cleaning and surface maintenance.
Title
Titles differ between systems:
IPC: CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OF BOILERS
CPC: CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS (cleaning pipes or tubes in general B08B9/02; devices or arrangements for removing water, minerals, or sludge from boilers while the boiler is in operation, or which remain in position while the boiler is in operation, or are specifically adapted to boilers without any other utility F22B37/48; removal or treatment of combustion products or combustion residues F23J; removing ice from heat-exchange apparatus F28F17/00)
Full Title
Full titles differ between systems:
CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OF BOILERS
CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS (cleaning pipes or tubes in general B08B9/02; devices or arrangements for removing water, minerals, or sludge from boilers while the boiler is in operation, or which remain in position while the boiler is in operation, or are specifically adapted to boilers without any other utility F22B37/48; removal or treatment of combustion products or combustion residues F23J; removing ice from heat-exchange apparatus F28F17/00)
IPC and CPC are identically structured here. All 8 subcodes exist in both systems.
6 shared codes have differing titles between IPC and CPC.
Child Classifications
Navigate with arrow keys, Enter to open
- F28G 1/00 Non-rotary, e.g. reciprocated, appliances (F28G3/00 takes precedence) IPC+CPC Available in IPC and CPC
- F28G 11/00 Cleaning by combustion, e.g. using squibs, using travelling burners IPC+CPC Available in IPC and CPC
- F28G 13/00 Appliances or processes not covered by groups F28G1/00 - F28G11/00; Combinations of appliances or processes covered by groups F28G1/00 - F28G11/00 +1 CPC IPC+CPC Available in IPC and CPC
- F28G 9/00 Cleaning by flushing or washing, e.g. with chemical solvents (appliances using jets of fluid for removing debris F28G1/16, F28G3/16) +1 CPC IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class F28,2013–2023, worldwide · Source: EPO PATSTAT
- VALEO SYSTEMES THERMIQUES FR 1,902
- MITSUBISHI ELECTRIC CORPORATION JP 1,327
- GREE ELECTRIC APPLIANCES 1,152
- MAHLE INTERNATIONAL DE 999
- ALFA LAVAL SE 960
- HANON SYSTEMS KR 917
- DENSO CORPORATION 905
- DENSO CORPORATION JP 802
- CHINESE ACADEMY OF SCIENCES 787
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 762
Top Applicants (CPC)
Class F28,2013–2023, worldwide · Source: EPO PATSTAT
- VALEO SYSTEMES THERMIQUES FR 1,945
- MITSUBISHI ELECTRIC CORPORATION JP 1,518
- MAHLE INTERNATIONAL DE 1,120
- ALFA LAVAL SE 1,085
- HANON SYSTEMS KR 939
- DENSO CORPORATION JP 900
- LG ELECTRONICS KR 861
- HAMILTON SUNDSTRAND US 795
- DAIKIN INDUSTRIES JP 608
- DENSO CORPORATION 537