Methods and apparatus to regulate a gaseous fuel system

An apparatus comprising:

• machine-readable instructions;
• and
• at least one programmable circuit to execute the machine-readable instructions to:
• responsive to an operating state of a gas turbine engine being a first operating state, cause a first valve of the gas turbine engine to be in an open state to cause a first fluid to flow through a first fluid supply line via the first valve, a second valve of the gas turbine engine in a closed state when the first valve is in the open state, the second valve fluidly coupled to the first fluid supply line and to a second fluid supply line, the second valve to receive a second fluid different than the first fluid;
• detect that the operating state of the gas turbine engine has changed from the first operating state to a second operating state;
• and
• responsive to the change, cause the second valve to move from the closed state to an open state to cause the second fluid to flow from the second fluid supply line to the first fluid supply line via the second valve.

A system comprising:

• a first actuator coupled to a first valve of a gas turbine engine, the first actuator to control a flow of a first fluid through the first valve;
• a second actuator coupled to a second valve of the gas turbine engine, the first valve magnetically coupled to the second valve;
• and
• at least one programmable circuit in communication with the first actuator to cause the first actuator to be in one of an energized state or a deenergized state based on an operating state of the gas turbine engine, the second actuator to control a flow of a second fluid through the second valve based on the first actuator being in the energized state or the deenergized state, the second fluid different than the first fluid.