Ducted gas turbine engine stability bleed valve with passive and active shutoff

A bleed air valve, comprising:

• a housing that includes an inlet at a first end, an outlet at a second end, and a center portion between the inlet and the outlet to selectively provide a pneumatic flow path between the inlet and the outlet via a passage in the center portion;
• a piston that moves along a center guide, where the piston includes a first piston surface and an opposing second piston surface, and the piston moves along the center guide in response to forces applied to the first piston surface and the second piston surface, where the piston is spring biased to an open position such that the housing inlet and the housing outlet are in fluid communication;
• a pressure divider network that includes a divider network inlet having an inlet cross sectional area in fluid communication with the passage, a divider network outlet having an outlet cross sectional area in fluid communication with ambient pressure, and a network chamber in fluid communication with the divider network inlet and the divider network outlet, where the network chamber has an intermediate pressure value between pressure at the divider network inlet and pressure at the divider network outlet;
• a valve that includes a valve inlet and a valve outlet, where the valve outlet is in fluid communication with the piston first surface;
• and
• a control valve that receives a command signal and in response provides compressed air to a control valve output that is in fluid communication with the valve inlet.

An aircraft gas turbine engine bleed air valve, comprising:

• a housing that includes an inlet at a first end, an outlet at a second end, and a center portion between the inlet and the outlet to selectively provide a pneumatic flow path between the inlet and the outlet via a passage in the center portion;
• a piston that axially moves along a center guide, where the piston includes a first piston surface and an opposing second piston surface, and the piston axially moves along the center guide in response to forces applied to the first piston surface and the second piston surface, where the piston is spring biased to an open position such that the inlet and the outlet are in fluid communication;
• a pressure divider network that includes a divider network inlet having an inlet cross sectional area in fluid communication with the passage, a divider network outlet having an outlet cross sectional area in fluid communication with ambient pressure, and a network chamber in fluid communication with the divider network inlet and the divider network outlet, where the network chamber has an intermediate pressure value between pressure at the divider network inlet and pressure at the divider network outlet;
• a shuttle valve that includes a shuttle valve inlet and a shuttle valve outlet, where the shuttle valve outlet is in fluid communication with the piston first surface;
• an electromechanical valve that receives a command signal and in response provides compressed air to an electromechanical valve output that is in fluid communication with the shuttle valve inlet;
• and
• a spring that applies a force to the second piston surface to spring bias the aircraft gas turbine engine bleed air valve to the open position to bleed compressor air to ambient.