# US 12,000,758 B2 · Leak detection for pressurized fluid systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,758 B2 - Document ID: US12000758B2 - Status: Granted - Kind: B2 - Application number: 17/343,705 - Filed: 2021-06-09 - Published: 2022-12-15 - Granted: 2024-06-04 - Earliest claimed: 2021-06-09 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Antwan Shenouda - Web page: https://patentgrep.com/patent/US12000758B2 ## CPC - G01M 3/025: {Details with respect to the testing of engines or engine parts} - G01M 3/26: by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors - B64D 37/32: Safety measures not otherwise provided for, e.g. preventing explosive conditions - G01M 3/2815: {using pressure measurements} - G01M 3/283: {for double-walled pipes} - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT ## Abstract In accordance with at least one aspect of this disclosure, a fluid system of an aircraft includes a primary fluid conduit that conveys a primary fluid, and a leak detection system disposed around at least a portion of the primary fluid conduit and forming one or more detection volumes. The leak detection system determines whether there is a primary fluid leak into the one or more detection volumes by sensing a pressure change in the one or more detection volumes. ## Claims ### Claim 1 A leak detection system, comprising: a leak detection module that operatively connects to one or more pressure sensors to receive signals from the one or more pressure sensors that sense pressure in a detection volume, the leak detection module operable to execute a method, the method comprising: determining or receiving a detection volume pressure based on the signals from the one or more pressure sensors; comparing the detection volume pressure to a primary leak threshold; outputting a primary fluid leak signal to indicate a primary fluid leak of a primary fluid between a primary fluid path and the detection volume when the detection volume pressure exceeds the primary leak threshold; monitoring the detection volume pressure after crossing the primary fluid leak threshold; and in response to a change in the detection volume pressure, outputting a dual primary-secondary fluid leak signal indicating a secondary fluid leak in addition to the primary fluid leak. ### Claim 2 (depends on 1) The system of claim 1, wherein the method further includes: outputting the dual primary-secondary fluid leak signal if the detection volume pressure stabilizes below a primary fluid pressure threshold. ### Claim 3 (depends on 1) The system of claim 1, wherein the method further includes: outputting the dual primary-secondary fluid leak signal if the detection volume pressure decreases after crossing the primary fluid leak threshold. ### Claim 4 (depends on 1) The system of claim 1, wherein the method further includes: outputting the dual primary-secondary fluid leak signal if the detection volume pressure stabilizes above a primary fluid pressure threshold, and subsequently decreases below the primary fluid pressure threshold. ### Claim 5 (depends on 1) The system of claim 1, wherein the method further includes: comparing the detection volume pressure to a secondary leak threshold; and outputting the secondary fluid leak signal to indicate the secondary fluid leak between the detection volume and an atmosphere if the detection volume pressure declines below the secondary leak threshold. ### Claim 6 (depends on 5) The system of claim 5, wherein the method further includes: monitoring the detection volume pressure after crossing the secondary fluid leak threshold; and outputting the dual primary-secondary fluid leak signal if the detection volume pressure stabilizes above an atmosphere pressure threshold. ### Claim 7 (depends on 5) The system of claim 5, wherein the method further includes: monitoring the detection volume pressure after crossing the secondary fluid leak threshold; and outputting the dual primary-secondary fluid leak signal if the detection volume pressure increases after crossing the secondary fluid leak threshold. ### Claim 8 (depends on 5) The system of claim 5, wherein the method further includes: monitoring the detection volume pressure after crossing the secondary fluid leak threshold; and outputting the dual primary-secondary fluid leak signal if the detection volume pressure stabilizes below an atmosphere pressure threshold, and subsequently increases above the atmosphere pressure threshold. ### Claim 9 (depends on 1) The system of claim 1, further comprising an engine control module that controls an engine based on signals received from the leak detection module. ### Claim 10 (depends on 9) The system of claim 9, wherein the engine control module shutdowns the engine and/or a fuel system thereof if a dual primary-secondary fluid leak is detected. ### Claim 11 A method for detecting a leak in a fuel system, comprising: determining or receiving a detection volume pressure based on signals from one or more pressure sensors; comparing the detection volume pressure to a primary fluid leak threshold; outputting a primary fluid leak signal to indicate a primary fluid leak of a primary fluid between a primary fluid path and the detection volume if the detection volume pressure exceeds the primary leak threshold; monitoring the detection volume pressure after crossing the primary fluid leak threshold; and in response to a change in the detection volume pressure, outputting a dual primary-secondary fluid leak signal indicating a secondary fluid leak in addition to the primary fluid leak. ### Claim 12 (depends on 11) The method of claim 11, further comprising: outputting the dual primary-secondary fluid leak signal if the detection volume pressure stabilizes below a primary fluid pressure threshold. ### Claim 13 A method for leak detection of a fluid system, comprising: pressurizing a primary fluid system to a primary fluid pressure; monitoring a detection volume pressure different from the primary fluid pressure; wherein if the detection volume pressure increases above a primary fluid leak threshold, outputting a primary fluid leak signal; monitoring the detection volume pressure after outputting the primary fluid leak signal; and in response to a decrease in the detection volume pressure below a secondary fluid leak threshold, determining a secondary fluid leak also exists and outputting a second fluid leak signal. ### Claim 14 (depends on 13) The method of claim 13, further comprising activating a maintenance indicator in response to the primary fluid leak signal alone or the secondary fluid leak signal alone. ### Claim 15 (depends on 13) The method of claim 13, further comprising: in response to receiving both a primary fluid leak signal and a secondary fluid leak signal, shutting down the primary fluid system. ### Claim 16 (depends on 13) The method of claim 13, further comprising: wherein if the detection volume pressure stabilizes below a primary fluid pressure threshold, shutting down the primary fluid system. ### Claim 17 (depends on 13) The method of claim 13, further comprising: wherein if the detection volume pressure increases from a lowest point, shutting down the primary fluid system. ### Claim 18 (depends on 13) The method of claim 13, further comprising: wherein if the detection volume pressure stabilizes above an atmosphere pressure threshold, determining a dual primary-secondary fluid leak exists and shutting down the primary fluid system. ### Claim 19 (depends on 13) The method of claim 13, wherein the fluid system is a fuel system. ### Claim 20 (depends on 13) The method of claim 13, wherein the fuel system is a hydrogen fuel system for an aircraft.