# US 10,370,114 B2 · Aircraft fuel tank inerting systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,114 B2 - Document ID: US10370114B2 - Status: Granted - Kind: B2 - Application number: 14/775,742 - Filed: 2014-03-05 - Published: 2016-02-11 - Granted: 2019-08-06 - Earliest claimed: 2013-03-13 - Assignees: Eaton Intelligent Power Limited - Applicants: Eaton Limited - Inventors: Matthew Darren Jones - Web page: https://patentgrep.com/patent/US10370114B2 ## CPC - B64D 37/32: Safety measures not otherwise provided for, e.g. preventing explosive conditions - A62C 3/08: in aircraft {(A62C3/0207 takes precedence)} - A62C 99/0018: {using gases or vapours that do not support combustion, e.g. steam, carbon dioxide} - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - A62C: FIRE-FIGHTING (fire-extinguishing compositions, use of chemical substances in extinguishing fires A62D1/00; spraying, applying liquids or other fluent materials to surfaces in general B05; alarm arrangements G08B, e.g. fire alarms actuated by smoke or gases G08B17/10) ## Abstract An aircraft fuel tank inerting system for a fixed wing aircraft having at least one main fuel tank in the wing and an associated surge tank includes a source of inerting fluid and a flow passage for supplying said inerting fluid to the main fuel tank and discharging it into the main filet tank through at least one discharge outlet. The flow passage includes a pressure relief arrangement adapted to discharge into the surge tank if a pressure in the main fuel tank exceeds a predetermined threshold. ## Claims ### Claim 1 An aircraft fuel tank inerting system for a fixed wing aircraft including at least one main fuel tank in the wing and an associated surge tank, the inerting system comprising: a source of inerting fluid; and a flow passage for supplying the inerting fluid to the main fuel tank and discharging it into the main fuel tank through at least one discharge outlet, wherein the flow passage includes a pressure relief arrangement adapted to discharge inerting fluid passing along the flow passage into the surge tank based on a pressure in the main fuel tank exceeding a predetermined threshold so that inerting fluid is ventable to atmosphere via the surge tank without over-pressurizing the main fuel tank, wherein the flow passage passes through the main fuel tank into the surge tank and then back into the main fuel tank to open into the main fuel tank, and wherein the pressure relief arrangement is disposed in a portion of the flow passage in the surge tank. ### Claim 2 (depends on 1) The aircraft fuel tank inerting system according to claim 1, wherein the flow passage includes a duct. ### Claim 3 (depends on 2) The aircraft fuel tank inerting system according to claim 2, wherein the pressure relief arrangement includes a pressure relief valve in the duct responsive at least in part to a pressure within the duct to open at a predetermined threshold. ### Claim 4 (depends on 2) The aircraft fuel tank inerting system according to claim 2, wherein the pressure relief arrangement comprises a relief valve disposed in the duct, the relief valve venting into the surge tank and being responsive, at least in part, to the pressure in the main fuel tank. ### Claim 5 (depends on 1) The aircraft fuel tank inerting system according to claim 1, wherein the surge tank is disposed outboard and adjacent the main fuel tank. ### Claim 6 (depends on 1) The aircraft fuel tank inerting system according to claim 1, wherein the surge tank includes a vent to ambient. ### Claim 7 (depends on 1) The aircraft tank inerting system according to claim 1, further comprising a vent line separate from the flow passage and adapted to vent the main fuel tank into the surge tank. ### Claim 8 A method of inerting an aircraft including at least one main fuel tank in the wing and an associated surge tank, the method comprising: providing a source of inerting fluid, providing a flow passage for supplying the inerting fluid to the main fuel tank and discharging it therein, and providing a pressure relief arrangement to discharge inerting fluid passing along the flow passage into the surge tank based on a pressure in the main fuel tank and/or the flow passage exceeding a predetermined threshold so that inerting fluid is ventable to atmosphere via the surge tank without over-pressurizing the main fuel tank, wherein the flow passage passes through the main fuel tank into the surge tank and then back into the main fuel tank to open into the main fuel tank, and wherein the pressure relief arrangement is disposed in a portion of the flow passage in the surge tank. ### Claim 9 (depends on 8) The method according to claim 8, further comprising providing a vent line separate from the flow passage and adapted to vent the main fuel tank into the surge tank.