Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a second solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a pressure-switching valve operatively coupled to the first and second solenoids. The system includes an actuator operatively coupled to the pressure outlet of the second solenoid.

Abstract: A hydraulic actuator system of an aircraft includes a hydraulic actuator having a housing with a piston having a piston shaft with a piston head attached thereto and arranged within the housing. The piston head divides in internal volume of the housing into an extend cavity and a retract cavity and the extend cavity is configured to be connected to low pressure fluid source. The system also includes a pressure selector unit fluidly connected to the retract cavity and configured to be connected to the low pressure fluid source and to a high pressure fluid source. The unit include three solenoids with the first and second connected in parallel to the fluid sources and the third solenoid having a third solenoid first input connected to the first solenoid output, a third solenoid second input connected to the second solenoid output, and a third solenoid output connected to the retract cavity.

Abstract: A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a second solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a pressure-switching valve operatively coupled to the first and second solenoids. The system includes an actuator operatively coupled to the pressure outlet of the second solenoid.

Abstract: A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. A second solenoid has at least one pressure input and a pressure outlet downstream from the at least one pressure input. A transfer solenoid operatively coupled to the first and second solenoids. An actuator valve operatively coupled to a pressure outlet of the transfer solenoid.

Abstract: A metering valve has a shutoff position at which it blocks flow from the metering valve outlet line from reaching an outlet to a use. A spool has a first end and a second end. The housing has a first shoulder associated with the first end and a second shoulder associated with the second end. In the shutoff position, the spool has the first end spaced from the first shoulder, and the second end spaced from the second shoulder. A fuel system for a gas turbine engine is also disclosed.

Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, a primary flow valve disposed on the primary flow line and configured to selectively allow injectant flow to the primary flow line, a secondary flow line connected to the main flow line, and a secondary flow valve disposed on the secondary flow line and configured to selectively allow injectant flow to the secondary flow line. The system can include a primary purge branch in fluid communication with the primary flow line and connected to a purge gas line, a primary purge valve disposed in the primary purge branch between the primary flow line and the purge gas line, a secondary purge branch in fluid communication with the secondary flow line, and a secondary purge valve disposed between the purge gas line and both of the primary purge branch and the secondary purge branch.

Abstract: A metering valve has a main inlet port and a spool movable, and a housing outlet port in a housing. The spool has a metering inlet orifice selectively aligned with the main inlet port, and a metering outlet orifice selectively aligned with the main outlet port. The main inlet port communicates with the metering inlet orifice, and the outlet port communicates with the metering outlet orifice to each provide a metering orifice. The main outlet port communicates downstream to a minimum pressure valve. The minimum pressure valve has a piston biased to a closed position by a spring force, and a line downstream of the main outlet port acting against a face of the piston in opposition to the spring force to ensure a minimum pressure moving downstream past the piston to a use. A fuel system is also disclosed.

Abstract: A metering valve has a shutoff position at which it blocks flow from the metering valve outlet line from reaching an outlet to a use. A spool has a first end and a second end. The housing has a first shoulder associated with the first end and a second shoulder associated with the second end. In the shutoff position, the spool has the first end spaced from the first shoulder, and the second end spaced from the second shoulder. A fuel system for a gas turbine engine is also disclosed.

Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, a primary flow valve disposed on the primary flow line and configured to selectively allow injectant flow to the primary flow line, a secondary flow line connected to the main flow line, and a secondary flow valve disposed on the secondary flow line and configured to selectively allow injectant flow to the secondary flow line. The system can include a primary purge branch in fluid communication with the primary flow line and connected to a purge gas line, a primary purge valve disposed in the primary purge branch between the primary flow line and the purge gas line, a secondary purge branch in fluid communication with the secondary flow line, and a secondary purge valve disposed between the purge gas line and both of the primary purge branch and the secondary purge branch.