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CPC Main Group Additional Only
F23J 2211/00

Flue gas duct systems

4 direct subcodes

Child Classifications

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  • F23J 2211/20 Common flues for several combustion devices
  • F23J 2211/30 Chimney or flue associated with building ventilation system
  • F23J 2211/40 Chimney with internal flue pipe system

Top Applicants

Top 10 applicants by patent filingsfor class F23, 2013–2023, worldwide · Source: EPO PATSTAT

  1. GE (GENERAL ELECTRIC COMPANY) US 2,581
  2. UNITED TECHNOLOGIES CORPORATION (UTC) US 1,180
  3. SIEMENS DE 1,157
  4. GE (GENERAL ELECTRIC COMPANY) 994
  5. XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 769
  6. MITSUBISHI HEAVY INDUSTRIES JP 701
  7. MITSUBISHI HITACHI POWER SYSTEMS JP 695
  8. RAYTHEON TECHNOLOGIES CORPORATION US 587
  9. NINGBO FOTILE KITCHENWARE COMPANY 543
  10. GENERAL ELECTRIC TECHNOLOGY CH 490