Valve assembly

A valve assembly for an anti-ice system of an aircraft, comprising:

• a first piston moveable between a first position and a second position;
• a regulating piston having an interior and an exterior;
• and
• a valve body;
• wherein the valve body defines a valve inlet, a valve outlet, a fluid passage between the valve inlet and the valve outlet, and a core portion defining a first chamber by cooperation with the first piston and a regulating chamber by cooperation with the regulating piston;
• wherein the regulating piston comprises:
• an inlet port arranged to permit fluid flow between the exterior and interior of the regulating piston;
• and
• an outlet arranged to permit fluid flow from the interior of the regulating piston to the valve outlet;
• wherein the regulating piston is movable between a first position in which the inlet port permits fluid flow between the valve inlet and the valve outlet via the fluid passage and the interior of the regulating piston, and a second position in which the inlet port is located within the core portion of the valve body so that the regulating piston prevents fluid flow from the valve inlet to the valve outlet;
• and
• wherein the first piston overlaps the regulating piston when the first piston is its first position and the regulating piston is in its second position.