Patent ID: 8602382

Claim:
A valve assembly regulating a supply of fluid from a fluid manifold to a working chamber of a fluid working machine, the valve comprising; a primary valve, an electromagnet and an armature, the primary valve comprising a face-seating primary valve member and a primary valve seat and having an open position in which the primary valve member is spaced apart from the primary valve seat and a sealing position in which the primary valve member is in sealing contact with the primary valve seat, wherein the armature is slidable along a path extending between a first position and a second position, and wherein, when the armature is in the first position, the primary valve member is biased towards the sealing position, wherein, when the armature is in the second position, the primary valve member is biased towards the open position wherein the primary valve member comprises a ferromagnetic member and the valve assembly further comprises a magnetic circuit adapted to direct magnetic flux through the ferromagnetic member when the primary valve is open to thereby hold the primary valve member in the open position.