CPC technology class · E03

E03F - Sewers

Sewers; cesspools. 1,375 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

1,375
US patents granted: #4/4
in E03: 18.8%
E03 class share: +18%
5-yr velocity

The verdict

According to USPTO PatentsView, Sewers ranks #416 of 670 CPC technology areas - 1,375 US patents granted since 2015, with recorded grant volume up 18% over five years.

#416
of 670 CPC technology areas: 1,375
US patents granted, 2015–2025: Milwaukee Electric Tool
leading assignee (37): +18%
grant velocity, last 5 yrs

How E03F's grant cadence moved

Between 2020–2024, E03F recorded 678 grants versus 575 in 2015–2019 (+18% equal-window velocity). Across complete years, output peaked in 2019 at 177 grants and bottomed in 2015 at 74 (+139% peak-over-trough). Lead assignee MAG Aerospace Industries, LLC holds 1.9% of the class ; the top three share 5.5%.

Leaderboard read

E03F concentration, lead at 1.9%

MAG Aerospace Industries, LLC leads this historical grant record at 1.9% of E03F - us corporation assignees hold 71% of class grants (492 of 693). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 1.9%
Top three share: 5.5%
Lead over #2: 1

Where E03F sits inside E03

Among 4 subclasses in E03 (Water SUPPLY; Sewerage), E03F ranks #4 and holds 18.8% of the parent class's 7,304 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

E03C 2,911 E03D 1,515 E03B 1,503

Rising assignees active in E03F

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 Chongqing University 9.29x 7 → 65 company-wide · 6 in E03F
#2 Modology Design Group 8.00x 0 → 8 company-wide · 8 in E03F
#3 Zoeller Pump Company, LLC 7.00x 1 → 7 company-wide · 7 in E03F
#4 ACO Ahlmann SE & Co. KG 6.00x 0 → 6 company-wide · 8 in E03F
#5 Watts Regulator Co. 3.33x 15 → 50 company-wide · 9 in E03F

E03F grants by year, peak 2019 (177)

US utility-patent grants per year in E03F, 2015–2025 - recent five years are up 18% versus 2015–2019.

Mag Aerospace…

26
Zurn Industries

25
Advanced Drainage…

25
Bio Clean Environmenta…

22
Seescan

21
Ridge Tool

18
Thermaco Incorporated

17
Infiltrator Water

15
Oatey

13
Aco Sevrin Ahlmann &…

13
Lmk

12
Oldcastle Precast

11

What this shows Milwaukee Electric… is the most active filer in E03F, holding 37 of the 1,375 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 E03F
Rank	Company	Patents in E03F
#1	MAG Aerospace Industries, LLC	26
#2	Zurn Industries, LLC	25
#3	Advanced Drainage Systems, Inc.	25
#4	BIO Clean Environmental Services, LLC	22
#5	SeeScan, Inc.	21
#6	Ridge Tool Company	18
#7	Thermaco Incorporated	17
#8	Infiltrator Water Technologies, LLC	15
#9	Oatey Co.	13
#10	ACO Sevrin Ahlmann GMBH & Co KG	13
#11	LMK Technologies, LLC	12
#12	Oldcastle Precast Inc.	11
#13	Waskey Bridges, Inc.	11
#14	Oldcastle Infrastructure, Inc.	11
#15	iPEK International GmbH	11
#16	Watts Regulator Co.	9
#17	Hydro International Ltd	9
#18	Stormtrap, LLC	9
#19	Schluter Systems L.P.	8
#20	Contech Engineered Solutions LLC	8

Footprint here vs. claim strategy

Each dot is a leading E03F 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 E03F assignees by class footprint. Bubble size = patents in E03F. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near E03F's 1,375-grant footprint

Nationwide nearest neighbors for E03F (#416 of 670 by volume ; lead share 2.7%) - not the E03 parent-class siblings above.

Nearest by grant volume

C10J 1,392 B66D 1,354 A22C 1,343 G04F 1,418

Nearest by lead-assignee share

F28F 2.7% A23P 2.7% B29K 2.7% G16H 2.7%

Questions about E03F

Which company holds the most patents in E03F?

Milwaukee Electric Tool Corporation leads E03F with 37 patents (1.9% of the subclass). By PatentsView assignee type, us corporations account for 71% of class grants.

Which E03F assignees grew fastest recently?

Among assignees with ≥5 grants in E03F, Chongqing University shows the highest company-wide grant multiple (9.29x: 7 grants in 2019–2021 → 65 in 2022–2024) while holding 6 patents in this subclass. Growth is company-wide, not class-only.

How does E03F compare inside parent class E03?

Inside E03 (Water SUPPLY; Sewerage), E03F ranks #4 of 4 subclasses by grant volume and holds 18.8% of the parent class total. The largest sibling is E03C (2,911 grants).

What to do with this data

E03F in context - here's where to go next.

MAG Aerospace Industries, LLC leads E03F with 26 grants in this class. See full portfolio
E03F ranks #416 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class E03, the largest sibling subclass is E03C with 2,911 grants. Explore E03C

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

Methodology - E03F figures are USPTO PatentsView granted-utility totals for this subclass (1,375 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.