IPC Main Group
F22D 5/00 Controlling water feed or water level; Automatic water feeding or water-level regulators
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- Class:
- STEAM GENERATION
- Subclass:
- PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
8 direct subcodes
Child Classifications
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- F22D 5/02 with an intermediate compartment from which the water is fed by gravity after mechanically moving the compartment, the movement being controlled according to water level
- F22D 5/04 with pivoting buckets
- F22D 5/06 with receptacles external to, but in free communication with, the boilers and adapted to move up and down in accordance with change in water level
- F22D 5/08 with float-actuated valves
- F22D 5/14 responsive to thermal expansion and contraction, e.g. of solid elements
- F22D 5/18 for varying the speed or delivery pressure of feed pumps
- F22D 5/24 with electric switches
- F22D 5/26 Automatic feed-control systems
Top Applicants
Top 10 applicants by patent filingsfor class F22, 2013–2023, worldwide · Source: EPO PATSTAT
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 922
- MIURA COMPANY 416
- HARBIN BOILER COMPANY 390
- MITSUBISHI HITACHI POWER SYSTEMS 303
- XIAN JIAOTONG UNIVERSITY 287
- SGCC(STATE GRID CORPORATION OF CHINA) 257
- HUADIAN ELECTRIC POWER RESEARCH INSTITUTE 253
- SIEMENS DE 247
- MIDEA 243
- NORTH CHINA ELECTRIC POWER UNIVERSITY 223