Patent ID: 8167581

Claim:
A device for delivering a liquid, which device comprises: a pump of a positive displacement type having an inlet valve, an outlet valve and an inlet duct suitable for being connected to an upstream liquid reservoir and connected to said inlet valve of the pump, said inlet valve of the pump being placed downstream of the inlet duct, an outlet duct connected to said outlet valve of the pump, which outlet valve is made of a rigid material, an anti-siphon valve external to the pump and having an inlet channel connected directly to the outlet duct of the pump, and an outlet channel, disposed between the inlet channel and the outlet channel are a seat and a moving member that co-operate together and that define, between the inlet channel and the outlet channel, a leaktight liquid flow zone, the moving member having a top surface and a bottom surface; and a reference chamber that is not in fluid communication with the outlet channel and having a reference pressure (P ref ), the top surface of the moving member being in contact with a fluid contained within the reference chamber having the reference pressure (P ref ), wherein said moving member moves from an opening position allowing the liquid to flow through said liquid flow zone, to a closure position in which the moving member comes into contact with the seat of the anti-siphon valve and prevents a flow through said liquid flow zone, when said moving member is subjected to at least said reference pressure (P ref ), wherein said reference pressure (P ref ) is substantially equal to a pressure prevailing, when the pump is at rest, in the inlet duct of the pump, and wherein the seat or the moving member of said anti-siphon valve comprises a pliable material.