Systems and methods for at-cylinder fuel switching
US-12535041-B2 · Jan 27, 2026 · US
Shut-off valves; Check valves; Safety valves; Pressure relief valves
Shut-off valves; Check valves; Safety valves; Pressure relief valves · Cooperative Patent Classification (CPC)
Engines, pumps, lighting, heating, and mechanical systems.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | F02D19/0681 |
| Official title | {Shut-off valves; Check valves; Safety valves; Pressure relief valves} |
| Display label | Shut-off valves; Check valves; Safety valves; Pressure relief valves |
| Total patents | 46 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is growing.
| Year | Patents |
|---|---|
| 2015 | 5 |
| 2016 | 4 |
| 2017 | 2 |
| 2018 | 4 |
| 2019 | 7 |
| 2020 | 3 |
| 2021 | 5 |
| 2022 | 4 |
| 2023 | 2 |
| 2024 | 2 |
| 2025 | 7 |
| 2026 | 1 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Dual fuel system and operating strategy metering fuel via varied fuel pump output
US-12486809-B2 · Dec 2, 2025 · US
Dual fuel system and operating strategy metering fuel via varied fuel pump output
US-2025314211-A1 · Oct 9, 2025 · US
Dual fuel system having overflow buffer for hastening fuel switchover
US-12359632-B1 · Jul 15, 2025 · US
Gas supply system for a gas engine or dual-fuel engine and method for operating the same
US-12345213-B2 · Jul 1, 2025 · US
Systems and methods for at-cylinder fuel switching
US-2025179970-A1 · Jun 5, 2025 · US
Dual fuel system for engine having fuel-actuated fuel pump and method
US-2025101926-A1 · Mar 27, 2025 · US
Quick start fuel system for gaseous fuel internal combustion engine and method
US-12188421-B2 · Jan 7, 2025 · US
Quick start fuel system for gaseous fuel internal combustion engine and method
US-2024254933-A1 · Aug 1, 2024 · US
Fuel system for prime mover
US-11885269-B1 · Jan 30, 2024 · US
Apparatus and method for charging LPG fuel of bi-fuel vehicle
US-11761389-B2 · Sep 19, 2023 · US
Methods and systems for shut down of a multi-fuel engine
US-2023193840-A1 · Jun 22, 2023 · US
System and method for controlling flow in a fuel recirculation line
US-11493000-B1 · Nov 8, 2022 · US
System and method for controlling flow in a fuel recirculation line
US-2022349364-A1 · Nov 3, 2022 · US
Gas fuel supply system
US-11466646-B2 · Oct 11, 2022 · US
Apparatus and method for charging lpg fuel of bi-fuel vehicle
US-2022298980-A1 · Sep 22, 2022 · US
Gas supply system for a gas engine or dual-fuel engine and method for operating the same
US-2021396187-A1 · Dec 23, 2021 · US
Gas fuel supply system
US-2021317801-A1 · Oct 14, 2021 · US
Fuel system for a multi-fuel internal combustion engine
US-11143120-B2 · Oct 12, 2021 · US
Multi-fuel transport refrigeration unit
US-10941713-B2 · Mar 9, 2021 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC F02D19/0681?
- CPC F02D19/0681 is the Cooperative Patent Classification code for “Shut-off valves; Check valves; Safety valves; Pressure relief valves.”
- How many patents are filed under CPC F02D19/0681 (Shut-off valves; Check valves; Safety valves; Pressure relief valves)?
- Our database includes 46 publications tagged with this CPC code.
- Is patent activity under CPC F02D19/0681 growing?
- Publication counts under this code: 2 in 2024 vs 7 in 2025 (latest complete years).