VALVE ASSEMBLY

A valve assembly 100 for an anti-ice system of an aircraft. The valve assembly 100 comprises: a valve body 110; a first piston 120; and a regulating piston 140. The valve body 110 defines a valve inlet 112, a valve outlet 114, a fluid passage between the valve inlet 112 and the valve outlet 114, and a core portion 116 defining a first chamber 112 by cooperation with the first piston 120 and a regulating chamber 142 by cooperation with the regulating piston 140. The first piston 120 is moveable between a first position and a second position, and the regulating piston 140 is movable between a first position and a second position. The first piston 120 overlaps the regulating piston 140 when the first piston 120 is its first position and the regulating piston 140 is in its second position.