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PCE
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DIFF Subgroup
E21F 1/04

Air ducts (suspension devices E21F17/02)

Introduced: September 1968

Title

Titles differ between systems:

IPC: Air ducts

CPC: Air ducts (suspension devices E21F17/02)

Full Title

Full titles differ between systems:

IPC:

Ventilation of mines or tunnels; Distribution of ventilating currents > Air ducts

CPC:

Ventilation of mines or tunnels; Distribution of ventilating currents (ventilating rooms or spaces in general F24F) > Air ducts (suspension devices E21F17/02)

IPC and CPC are identically structured here. All 1 subcodes exist in both systems.

1 shared codes have differing titles between IPC and CPC.

Child Classifications

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  • E21F 1/06 Duct connections (tube connections in general F16L) IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 26,607
  2. PETROCHINA COMPANY 14,382
  3. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
  4. CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
  5. BAKER HUGHES US 6,269
  6. SCHLUMBERGER TECHNOLOGY US 5,929
  7. SAUDI ARABIAN OIL COMPANY SA 5,880
  8. SOUTHWEST PETROLEUM UNIVERSITY 4,477
  9. CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
  10. SCHLUMBERGER TECHNOLOGY NL 4,219

Top Applicants (CPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 27,652
  2. SAUDI ARABIAN OIL COMPANY SA 7,755
  3. PETROCHINA COMPANY 7,025
  4. BAKER HUGHES US 6,589
  5. SCHLUMBERGER TECHNOLOGY US 6,151
  6. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 4,443
  7. SCHLUMBERGER TECHNOLOGY NL 4,255
  8. CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 3,991
  9. SERVICES PETROLIERS SCHLUMBERGER FR 3,300
  10. SCHLUMBERGER CANADA CA 3,086