A method of removing hydraulic fluid from an aircraft hydraulic system is disclosed including a hydraulically actuated mechanism that is actuated by an electrohydraulic servo valve, a hydraulic fluid port through which hydraulic fluid can escape, and a hydraulic fuse with a closed state and an open state between the electrohydraulic servo valve and the hydraulic fluid port. The hydraulic fluid port is opened, and then the activation of the electrohydraulic servo valve is controlled to force hydraulic fluid to escape from the hydraulic system via the hydraulic fluid port, the control being so that the hydraulic fuse does not enter and remain in the closed state.

A valve body has an outside surface and a cylinder. The cylinder has an inlet chamber and an outlet chamber. A piston has a head at one end and a foot at the end opposite the head and a piston body between the head and the foot. A cross channel extends from a first side of the piston body. A longitudinal channel is in fluid communication with the cross channel and extends to the outlet chamber. The piston is positioned in the cylinder so that it can be moved to an open position in which the cross channel is in fluid communication with the inlet chamber and a closed position in which the cross channel is not in fluid communication with the inlet chamber. The piston is actuated between the two positions by a differential in pressure between the inlet chamber and the outlet chamber.

A regulator may include a fuel inlet from which a high-pressure fluid is introduced, a valve seat provided at the fuel inlet, and a pressure regulating valve body. The fluid may pass an opening between the valve seat and the pressure regulating valve body formed with a communication passage to a pressure regulating chamber provided to face a valve-seated seat arranged on the pressure regulating chamber side of the valve seat. A load generated by pressure of pressure-regulated fluid acting on a piston unit joined to the pressure regulating valve body may be balanced with a load by a pressure regulating spring in an atmosphere chamber provided coaxially in parallel with the pressure regulating chamber on an opposite side of the pressure regulating chamber of the piston unit. Fluid pressure of the pressure regulating chamber may be controlled by changing an opening area between the valve-seated seat and the pressure regulating valve body. The valve seat holding the valve-seated seat may be installed on an elastic member via a buffer having a sliding performance for automatic alignment to enable uniform contact between the pressure regulating valve body and valve-seated seat.

The breaker box assembly may include a plurality of breaker modules that are removably attached to each other. Each breaker module includes a body and a first valve assembly disposed within the body. The body includes an inlet and first and second outlets. The first valve assembly is movable between a first position in which fluid is allowed to flow to the first and second outlets and a second position in which fluid is prevented from flowing to the first outlet and is permitted to flow to the second outlet.

A venturi vacuum drawback assembly includes a fluid supply passage that supplies the fluid to the device, a fluid return passage that returns the fluid to the device, a shutoff valve positioned on the fluid supply passage, a bypass passage, a bypass valve positioned on the bypass passage, and a venturi valve positioned on the bypass passage downstream of the bypass valve. The bypass passage includes an inlet and an outlet. The inlet is connected to the fluid supply passage upstream of the shutoff valve, and the outlet connected to the fluid return passage. The venturi valve includes a venturi inlet, a venturi outlet, and a primary orifice positioned between the venturi inlet and the venturi outlet. The primary orifice is connected to a drawback opening on the fluid supply passage by a conduit. The drawback opening of the fluid supply passage is positioned downstream of the shutoff valve.

A venturi vacuum drawback assembly includes a fluid supply passage that supplies the fluid to the device, a fluid return passage that returns the fluid to the device, a shutoff valve positioned on the fluid supply passage, a bypass passage, a bypass valve positioned on the bypass passage, and a venturi valve positioned on the bypass passage downstream of the bypass valve. The bypass passage includes an inlet and an outlet. The inlet is connected to the fluid supply passage upstream of the shutoff valve, and the outlet connected to the fluid return passage. The venturi valve includes a venturi inlet, a venturi outlet, and a primary orifice positioned between the venturi inlet and the venturi outlet. The primary orifice is connected to a drawback opening on the fluid supply passage by a conduit. The drawback opening of the fluid supply passage is positioned downstream of the shutoff valve.

A valve body has an outside surface and a cylinder. The cylinder has an inlet chamber and an outlet chamber. A piston has a head at one end and a foot at the end opposite the head and a piston body between the head and the foot. A cross channel extends from a first side of the piston body. A longitudinal channel is in fluid communication with the cross channel and extends to the outlet chamber. The piston is positioned in the cylinder so that it can be moved to an open position in which the cross channel is in fluid communication with the inlet chamber and a closed position in which the cross channel is not in fluid communication with the inlet chamber. The piston is actuated between the two positions by a differential in pressure between the inlet chamber and the outlet chamber.

A venturi vacuum drawback assembly includes a fluid supply passage that supplies the fluid to the device, a fluid return passage that returns the fluid to the device, a shutoff valve positioned on the fluid supply passage, a bypass passage, a bypass valve positioned on the bypass passage, and a venturi valve positioned on the bypass passage downstream of the bypass valve. The bypass passage includes an inlet and an outlet. The inlet is connected to the fluid supply passage upstream of the shutoff valve, and the outlet connected to the fluid return passage. The venturi valve includes a venturi inlet, a venturi outlet, and a primary orifice positioned between the venturi inlet and the venturi outlet. The primary orifice is connected to a drawback opening on the fluid supply passage by a conduit. The drawback opening of the fluid supply passage is positioned downstream of the shutoff valve.

A venturi vacuum drawback assembly includes a fluid supply passage that supplies the fluid to the device, a fluid return passage that returns the fluid to the device, a shutoff valve positioned on the fluid supply passage, a bypass passage, a bypass valve positioned on the bypass passage, and a venturi valve positioned on the bypass passage downstream of the bypass valve. The bypass passage includes an inlet and an outlet. The inlet is connected to the fluid supply passage upstream of the shutoff valve, and the outlet connected to the fluid return passage. The venturi valve includes a venturi inlet, a venturi outlet, and a primary orifice positioned between the venturi inlet and the venturi outlet. The primary orifice is connected to a drawback opening on the fluid supply passage by a conduit. The drawback opening of the fluid supply passage is positioned downstream of the shutoff valve.

The breaker box assembly may include a plurality of breaker modules that are removably attached to each other. Each breaker module includes a body and a first valve assembly disposed within the body. The body includes an inlet and first and second outlets. The first valve assembly is movable between a first position in which fluid is allowed to flow to the first and second outlets and a second position in which fluid is prevented from flowing to the first outlet and is permitted to flow to the second outlet.