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DIFF Main Group
F22B 23/00

Water-tube boilers built-up from sets of spaced double-walled water tubes of return type in unilateral abutting connection with a boiler drum or with a header box, i.e. built-up from Field water tubes comprising an inner tube arranged within an outer unilaterally-closed tube

Introduced: September 1968

IPC and CPC are identically structured here. All 3 subcodes exist in both systems.

Child Classifications

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  • F22B 23/02 the water-tube, i.e. Field-tube, sets being horizontal or substantially horizontal IPC+CPC Available in IPC and CPC
  • F22B 23/04 the water-tube, i.e. Field-tube, sets being vertical or substantially vertical IPC+CPC Available in IPC and CPC
  • F22B 23/06 Component parts thereof, e.g. Field water tubes IPC+CPC Available in 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