Abstract: In accordance with at least one aspect of this disclosure, a system includes, a first moveable member disposed in a first chamber configured to move between a first position and a second position of the first moveable member to allow or prevent fluid from passing from an inlet of the first chamber to an outlet of the first chamber. A second moveable member is disposed in a second chamber configured to move between a first position and a second position of the second moveable member to allow or prevent fluid from entering a biasing chamber, the second chamber being fluidly connected to the first chamber.

Abstract: In accordance with at least one aspect of this disclosure, a system includes, a first moveable member disposed in a first chamber configured to move between a first position and a second position of the first moveable member to allow or prevent fluid from passing from an inlet of the first chamber to an outlet of the first chamber. A second moveable member is disposed in a second chamber configured to move between a first position and a second position of the second moveable member to allow or prevent fluid from entering a biasing chamber, the second chamber being fluidly connected to the first chamber.

Abstract: A sleeve valve includes an inlet port and an outlet port. A sleeve is movable to close flow from the inlet port to the outlet port. The sleeve valve has a sleeve biased to an open position at which it allows flow from the inlet port to the outlet port by a spring. Pressure in a pressure chamber urges the sleeve to a closed position at which it blocks flow from the inlet port to the outlet port. A line pressure conduit communicates the fluid chamber into the pressure chamber. Pressurized air is supplied to the pressure chamber through a selectively closed valve. The selectively closed valve is opened to allow the flow of high pressure air from a pressure source into the pressure chamber to move the sleeve to a closed position. A bleed air system for a gas turbine engine is also disclosed.

Abstract: A bleed valve for an air plenum includes a valve body having a poppet seat, a poppet supported by the valve body and movable relative to the poppet seat, and piston slideable relative to the poppet and movable relative to the poppet between an extended position and a retracted position. Gas turbine engines and methods of bleeding fluid from gas turbine engines are also described.

Abstract: A sleeve valve includes an inlet port and an outlet port. A sleeve is movable to close flow from the inlet port to the outlet port. The sleeve valve has a sleeve biased to an open position at which it allows flow from the inlet port to the outlet port by a spring. Pressure in a pressure chamber urges the sleeve to a closed position at which it blocks flow from the inlet port to the outlet port. A line pressure conduit communicates the fluid chamber into the pressure chamber. Pressurized air is supplied to the pressure chamber through a selectively closed valve. The selectively closed valve is opened to allow the flow of high pressure air from a pressure source into the pressure chamber to move the sleeve to a closed position. A bleed air system for a gas turbine engine is also disclosed.

Abstract: A bleed valve for an air plenum includes a valve body having a poppet seat, a poppet supported by the valve body and movable relative to the poppet seat, and piston slideable relative to the poppet and movable relative to the poppet between an extended position and a retracted position. Gas turbine engines and methods of bleeding fluid from gas turbine engines are also described.

Abstract: A bleed valve for an air plenum includes a valve body having a poppet seat, a poppet supported by the valve body and movable relative to the poppet seat, and piston slideable relative to the poppet and movable relative to the poppet between an extended position and a retracted position. Gas turbine engines and methods of bleeding fluid from gas turbine engines are also described.

Abstract: A valve according to an example of the present disclosure includes a poppet head configured to move with respect to a valve outlet of the valve. A first spring is configured to be compressed with a force generated by fluid flow through the valve, and compression of the first spring allows the poppet head to move towards the valve outlet. A second spring is configured to allow the poppet head to move toward the valve outlet when compressed. A method for controlling fluid flow is also disclosed.

Abstract: A bleed valve includes a valve housing defining an inlet and an outlet with a flow path for fluid communication from the inlet to the outlet. A poppet head is connected to the valve housing by a primary spring and a secondary spring. The poppet head is configured for movement relative to the valve housing between: a fully open position in which the poppet head is spaced apart from the inlet to allow flow through the flow path, with the primary spring and secondary spring both expanded; a partially closed position in which the poppet head is spaced apart from the inlet but is closer to the inlet than in the fully open position, with the primary spring compressed; and a fully closed position in which the poppet head seats against the valve housing blocking flow through the flow path, with the primary spring and the secondary spring both compressed.

Abstract: According to one embodiment, an air turbine starter is provided. The air turbine starter comprising: a turbine wheel including a hub integrally attached to a turbine rotor shaft and a plurality of turbine blades extending radially outward from the hub; an inlet housing at least partially surrounding the turbine wheel; a nozzle located upstream from the turbine wheel and contained within the inlet housing defining an inlet flowpath between the nozzle and the inlet housing, the inlet flowpath directs air flow into the turbine blades; and a plurality of turbine vanes rotatably connected to the nozzle, each turbine vane extending radially from the nozzle into the inlet flowpath towards the inlet housing; wherein the plurality of turbine vanes are operable to adjust air flow through the inlet flowpath by rotating each turbine vane.

Abstract: A solenoid includes a coil defining an axis, an armature disposed radially inward of the coil, and a plurality of linear guides disposed at least partially between a radially inward facing surface of the coil and a radially outward facing surface of the armature. Each of the linear guides has a frictional surface area, with a dimension of the frictional surface area aligned with the axis being larger than a dimension of the frictional surface area aligned with a circumference of the coil.

Abstract: An example arrangement for cooling a gas turbine engine includes an air turbine starter having a turbine section for rotationally driving a compressor through rotation of a shaft. An starter air valve is configured to control a flow of pressurized air that flows downstream towards turbine blades of the air turbine starter. An airflow adjustment device (AAD) is configured to adjust the flow when a manual override feature of the starter air valve is engaged based on a rotational speed of one of the shaft and an additional shaft that is driven by the compressor. A governor is configured to control a degree to which the AAD adjusts the flow. The governor is mechanically linked to the shaft through one or more gears and configured to adjust the AAD such that a rotational speed of said one the shafts does not exceed a predefined threshold during a particular operating mode.

Abstract: According to an aspect, a system includes a starter air valve in fluid communication with an air turbine starter to drive motoring of a gas turbine engine responsive to a compressed air flow from a compressed air source. The system also includes a variable-position electromechanical device operable to adjust positioning of the starter air valve and a discrete-position electromechanical device operable to adjust positioning of the starter air valve and limit a motoring speed of the gas turbine engine below a resonance speed of the gas turbine engine responsive to a pulse width modulation control based on a failure of the variable-position electromechanical device.

Abstract: An example arrangement for cooling a gas turbine engine includes an air turbine starter, a starter air valve, and an airflow adjustment device. The air turbine starter includes a turbine section for rotationally driving a compressor of a gas turbine engine through rotation of a shaft that connects the turbine section to the compressor. The starter air valve is configured to control a flow of pressurized air along a flow path from a source to turbine blades of the turbine section. The starter air valve includes a manual override feature that allows manual opening of the starter air valve. The airflow adjustment device is configured to adjust the flow of pressurized air along the flow path when the manual override feature is engaged based on a rotational speed of one of the shaft and an additional shaft that is driven by the compressor.

Abstract: A valve according to an example of the present disclosure includes a poppet head configured to move with respect to a valve outlet of the valve. A first spring is configured to be compressed with a force generated by fluid flow through the valve, and compression of the first spring allows the poppet head to move towards the valve outlet. A second spring is configured to allow the poppet head to move toward the valve outlet when compressed. A method for controlling fluid flow is also disclosed.

Abstract: A starter air valve comprising: a housing comprising an inlet at a first end, an outlet at a second end opposite the first end, and a center portion between first end and second end, the outlet being fluidly connected to the inlet through a fluid passage; a first piston located within the housing between the first end and center portion, the first piston comprising: a first cupped portion configured to form a first chamber with the housing proximate the first end; and a second piston located within the housing between the second end and center portion, the second piston comprising: a third cupped portion configured to form a third chamber with the housing proximate the second end; wherein the pistons are configured to regulate airflow through the fluid passage by adjusting at least one of a first pressure within the first chamber and a third pressure within the third chamber.

Abstract: A bleed valve includes a valve housing defining an inlet and an outlet with a flow path for fluid communication from the inlet to the outlet. A poppet head is connected to the valve housing by a primary spring and a secondary spring. The poppet head is configured for movement relative to the valve housing between: a fully open position in which the poppet head is spaced apart from the inlet to allow flow through the flow path, with the primary spring and secondary spring both expanded; a partially closed position in which the poppet head is spaced apart from the inlet but is closer to the inlet than in the fully open position, with the primary spring compressed; and a fully closed position in which the poppet head seats against the valve housing blocking flow through the flow path, with the primary spring and the secondary spring both compressed.

Abstract: A bleed valve for an air plenum includes a valve body having a poppet seat, a poppet supported by the valve body and movable relative to the poppet seat, and piston slideable relative to the poppet and movable relative to the poppet between an extended position and a retracted position. Gas turbine engines and methods of bleeding fluid from gas turbine engines are also described.

Abstract: A starter air valve comprising: a housing comprising an inlet at a first end, an outlet at a second end opposite the first end, and a center portion between the first and second end, the outlet being fluidly connected to the inlet through a fluid passage; a first piston located within the housing between first end and center portion, the first piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; a second piston located within the housing between second end and center portion, the second piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; and a manual override system configured to move from closed to open position at least one of the first and second pistons.

Abstract: A solenoid includes a coil defining an axis, an armature disposed radially inward of the coil, and a plurality of linear guides disposed at least partially between a radially inward facing surface of the coil and a radially outward facing surface of the armature. Each of the linear guides has a frictional surface area, with a dimension of the frictional surface area aligned with the axis being larger than a dimension of the frictional surface area aligned with a circumference of the coil.