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DIFF Subgroup
F22B 21/26

bent helically, i.e. coiled

Introduced: September 1968

Full Title

Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically > built-up from water tubes of form other than straight or substantially straight > bent helically, i.e. coiled

No child classifications to compare. This is a leaf node in both IPC and CPC.

Top Applicants

Top Applicants (IPC)

Class F22,2013–2023, worldwide · Source: EPO PATSTAT

  1. XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 922
  2. MIURA COMPANY 416
  3. HARBIN BOILER COMPANY 390
  4. MITSUBISHI HITACHI POWER SYSTEMS 303
  5. XIAN JIAOTONG UNIVERSITY 287
  6. SGCC(STATE GRID CORPORATION OF CHINA) 257
  7. HUADIAN ELECTRIC POWER RESEARCH INSTITUTE 253
  8. SIEMENS DE 247
  9. MIDEA 243
  10. NORTH CHINA ELECTRIC POWER UNIVERSITY 223

Top Applicants (CPC)

Class F22,2013–2023, worldwide · Source: EPO PATSTAT

  1. XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 544
  2. SIEMENS DE 306
  3. PHILIP MORRIS PRODUCTS CH 258
  4. GENERAL ELECTRIC TECHNOLOGY CH 254
  5. MITSUBISHI HITACHI POWER SYSTEMS JP 235
  6. XIAN JIAOTONG UNIVERSITY 214
  7. MITSUBISHI HEAVY INDUSTRIES JP 195
  8. MITSUBISHI HITACHI POWER SYSTEMS 169
  9. HARBIN BOILER COMPANY 166
  10. VALMET TECHNOLOGIES FI 155