CPC Main Group
F22D 1/00 Feed-water heaters, i.e. economisers or like preheaters
Filing statistics
CPC F22D 1/00 belongs to the parent subclass F22D, which recorded 5,699 patent applications worldwide between 2013 and 2023. Annual filings grew from 227 in 2013 to 702 in 2023 (+209%), peaking at 774 applications in 2020. The most active applicants in class F22 are XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY (544 applications), SIEMENS (306 applications) and PHILIP MORRIS PRODUCTS (258 applications).
Source: EPO PATSTAT, worldwide filings
12 direct subcodes
Child Classifications
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- F22D 1/02 with water tubes arranged in the boiler furnaces, fire tubes or flue ways
- F22D 1/16 with water tubes arranged otherwise than in the boiler furnace, fire tubes, or flue ways
- F22D 1/24 with fire tubes or flue ways traversing feed-water vessels
- F22D 1/26 with means, other than tubes, to separate water and heating medium, e.g. bulk heaters without internal flues or tubes, jacketted smoke-boxes or flue or flues
- F22D 1/28 for direct heat transfer, e.g. by mixing water and steam
- F22D 1/32 arranged to be heated by steam, e.g. bled from turbines
- F22D 1/36 Water and air preheating systems
- F22D 1/40 Combinations of exhaust-steam and smoke-gas preheaters
- F22D 1/42 specially adapted for locomotives
- F22D 1/50 incorporating thermal de-aeration of feed-water (de-aeration produced in the course of direct heat transfer F22D1/28)
Top Applicants
Top 10 applicants by patent filingsfor class F22, 2013–2023, worldwide · Source: EPO PATSTAT
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 544
- SIEMENS DE 306
- PHILIP MORRIS PRODUCTS CH 258
- GENERAL ELECTRIC TECHNOLOGY CH 254
- MITSUBISHI HITACHI POWER SYSTEMS JP 235
- XIAN JIAOTONG UNIVERSITY 214
- MITSUBISHI HEAVY INDUSTRIES JP 195
- MITSUBISHI HITACHI POWER SYSTEMS 169
- HARBIN BOILER COMPANY 166
- VALMET TECHNOLOGIES FI 155