CPC technology class · F22

F22B - Methods Of Steam Generation

Methods of steam generation; steam boilers. 1,959 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

1,959
US patents granted: #1/3
in F22: 82.1%
F22 class share: -17%
5-yr velocity

The verdict

According to USPTO PatentsView, Methods Of Steam Generation ranks #370 of 670 CPC technology areas - 1,959 US patents granted since 2015, with recorded grant volume down 17% over five years.

#370
of 670 CPC technology areas: 1,959
US patents granted, 2015–2025: General Electric
leading assignee (63): -17%
grant velocity, last 5 yrs

How F22B's grant cadence moved

Between 2020–2024, F22B recorded 810 grants versus 979 in 2015–2019 (-17% equal-window velocity). Across complete years, output peaked in 2019 at 248 grants and bottomed in 2024 at 143 (+73% peak-over-trough). Lead assignee General Electric Technology GMBH holds 2.9% of the class ; the top three share 6.9%.

Leaderboard read

F22B concentration, lead at 2.9%

General Electric Technology GMBH leads this historical grant record at 2.9% of F22B - us corporation assignees hold 53% of class grants (540 of 1,028). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 2.9%
Top three share: 6.9%
Lead over #2: 16

Where F22B sits inside F22

Among 3 subclasses in F22 (Steam Generation), F22B ranks #1 and holds 82.1% of the parent class's 2,387 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

F22D 238 F22G 190

Rising assignees active in F22B

Company-wide grant multiples (2022–2024 vs 2019–2021) among assignees with ≥5 patents in this subclass. Growth is company-wide; class patent counts are subclass-specific.

#1 Doosan Enerbility Co., Ltd. 121x 0 → 121 company-wide · 10 in F22B
#2 ICE Thermal Harvesting, LLC 45x 1 → 45 company-wide · 29 in F22B
#3 Rondo Energy, Inc. 36x 0 → 36 company-wide · 41 in F22B
#4 Nooter/Eriksen, Inc. 5.50x 2 → 11 company-wide · 7 in F22B
#5 Gecko Robotics, Inc. 3.15x 13 → 41 company-wide · 30 in F22B

F22B grants by year, peak 2019 (248)

US utility-patent grants per year in F22B, 2015–2025 - recent five years are down 17% versus 2015–2019.

General Electric…

57
Rondo Energy

41
Altria Client Services

37
Mitsubishi Hitachi…

32
Gecko Robotics

30
Ice Thermal Harvesting

29
Westinghouse Electric

28
Philip Morris Products

21
The Babcock & Wilcox

20
Alstom Technology

17
Fontem Holdings 1 B V

16
Rai Strategic Holdings

15

What this shows General Electric is the most active filer in F22B, holding 63 of the 1,959 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

View data table

Top patent holders in CPC subclass F22B
Rank	Company	Patents in F22B
#1	General Electric Technology GMBH	57
#2	Rondo Energy, Inc.	41
#3	Altria Client Services LLC	37
#4	Mitsubishi Hitachi Power Systems, Ltd.	32
#5	Gecko Robotics, Inc.	30
#6	ICE Thermal Harvesting, LLC	29
#7	Westinghouse Electric Company LLC	28
#8	Philip Morris Products S.A.	21
#9	The Babcock & Wilcox Company	20
#10	Alstom Technology Ltd	17
#11	Fontem Holdings 1 B.V.	16
#12	RAI Strategic Holdings, Inc.	15
#13	Doosan Heavy Industries & Construction Co., Ltd.	14
#14	Valmet Technologies Oy	14
#15	Miura Co., Ltd.	13
#16	Mitsubishi Power, Ltd.	12
#17	Nuscale Power, LLC	12
#18	GE-Hitachi Nuclear Energy Americas LLC	11
#19	8 Rivers Capital, LLC	11
#20	Malta Inc.	11

Footprint here vs. claim strategy

Each dot is a leading F22B assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 F22B assignees by class footprint. Bubble size = patents in F22B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near F22B's 1,959-grant footprint

Nationwide nearest neighbors for F22B (#370 of 670 by volume ; lead share 3.2%) - not the F22 parent-class siblings above.

Nearest by grant volume

A23G 1,990 B21B 1,895 B31B 2,038 F24D 2,041

Nearest by lead-assignee share

C11C 3.2% H02M 3.2% C30B 3.2% F16N 3.2%

Questions about F22B

Which company holds the most patents in F22B?

General Electric Company leads F22B with 63 patents (2.9% of the subclass). By PatentsView assignee type, us corporations account for 53% of class grants.

Which F22B assignees grew fastest recently?

Among assignees with ≥5 grants in F22B, Doosan Enerbility Co., Ltd. shows the highest company-wide grant multiple (121x: 0 grants in 2019–2021 → 121 in 2022–2024) while holding 10 patents in this subclass. Growth is company-wide, not class-only.

How does F22B compare inside parent class F22?

Inside F22 (Steam Generation), F22B ranks #1 of 3 subclasses by grant volume and holds 82.1% of the parent class total. The largest sibling is F22D (238 grants).

What to do with this data

F22B in context - here's where to go next.

General Electric Technology GMBH leads F22B with 57 grants in this class. See full portfolio
F22B ranks #370 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class F22, the largest sibling subclass is F22D with 238 grants. Explore F22D

Figures reflect USPTO PatentsView grant data through 2026-05-15; pending applications not yet granted are not counted.

Methodology - F22B figures are USPTO PatentsView granted-utility totals for this subclass (1,959 grants in the tracked window).

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.