Abstract: A seal-piercing device has a pyramidal array of knife-edged blades defining at least one face open to the flow of water. The open face is partly obscured by spreader elements preventing a flap of the cut seal material from closing off the flow of water through that face. Other faces of the pyramid are solid and have one or more holes adjacent their bases. The solid faces preferably have flap-restraining spreaders preventing one of the cut flaps from coming into an obstructing contact with the solid face. When water is drawn from the dispensing vessel of a dispenser equipped with the seal-piercer of the invention, the air entering the bottle may flow through the holes adjacent the bases of the closed faces and upward along each face into the bottle.