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CPC Main Group
F28F 11/00

Arrangements for sealing leaky tubes and conduits (stopping flow from or in pipes in general F16L55/10)

Filing statistics

CPC F28F 11/00 belongs to the parent subclass F28F, which recorded 83,812 patent applications worldwide between 2013 and 2023. Annual filings declined from 7,008 in 2013 to 6,475 in 2023 (-8%), peaking at 8,704 applications in 2017. The most active applicants in class F28 are VALEO SYSTEMES THERMIQUES (1,945 applications), MITSUBISHI ELECTRIC CORPORATION (1,518 applications) and MAHLE INTERNATIONAL (1,120 applications).

Source: EPO PATSTAT, worldwide filings

3 direct subcodes

Child Classifications

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  • F28F 11/02 using obturating elements, e.g. washers, inserted and operated independently of each other (F28F11/06 takes precedence)
  • F28F 11/04 using pairs of obturating elements, e.g. washers, mounted upon central operating rods (F28F11/06 takes precedence)
  • F28F 11/06 using automatic tube obturating appliances

Top Applicants

Top 10 applicants by patent filingsfor class F28, 2013–2023, worldwide · Source: EPO PATSTAT

  1. VALEO SYSTEMES THERMIQUES FR 1,945
  2. MITSUBISHI ELECTRIC CORPORATION JP 1,518
  3. MAHLE INTERNATIONAL DE 1,120
  4. ALFA LAVAL SE 1,085
  5. HANON SYSTEMS KR 939
  6. DENSO CORPORATION JP 900
  7. LG ELECTRONICS KR 861
  8. HAMILTON SUNDSTRAND US 795
  9. DAIKIN INDUSTRIES JP 608
  10. DENSO CORPORATION 537