Systems, apparatus, and methods to a flame out valve for a gaseous fuel system are disclosed. An example apparatus to reduce fuel combustion comprises: a first valve connected to a fuel supply line, the first valve including: a first plug to control a flow of fuel; a first spring coupled to a first end of the first plug; and a first magnet coupled to a second end of the first plug; a second valve connected to a purge system in parallel with the fuel supply line, the second valve including: a second plug to control a flow of a gas; a second spring coupled to a first end of the second plug; and a second magnet coupled to a second end of the second plug, the second magnet magnetically coupled to the first magnet; and an electromagnetic actuator coupled to at least one of the first or the second valve.

A dual-fuel turbine engine is a type of turbine engine that can operate using two different fuel sources, such as liquid fuel (e.g., diesel) and natural gas. For liquid fuels, the turbine engine includes a primary line to facilitate engine startup and a secondary line to modify power output. Generally, the turbine engine only uses one type of fuel for combustion at a time. The fuel lines and passages in the fuel nozzles that carry the unused fuel source should preferably be purged and sealed by a purging system to reduce coking. However, conventional purge systems typically purge and seal only the secondary line for liquid fuels. As a result, the passages in the fuel nozzles connected to the primary line are prone to coking. To address this problem, a purge system is disclosed that purges and seals the primary line and, optionally, the secondary line.