Patent ID: 7025083

Claim:
A device for over-pressure protection of a tank during filling with a liquid, comprising: a main body with an inlet that leads to an inlet chamber, an outlet that leads to an outlet chamber, and a valve seat having an opening that defines a passage therein, wherein the passage interconnects the inlet chamber to the outlet chamber, said main body also featuring a working chamber and an open section in communication with the working chamber; a closing element disposed within said main body and movable between an open position where liquid may flow through the passage and a closed position where the closing element engages the valve seat so that liquid is prevented from flowing through the passage; and a piston movably disposed within a working chamber within the main body and connected to the closing element by a pull rod, said working chamber in communication with the outlet chamber so that said piston is adapted to communicate with the tank through the main body outlet so that the closing element is moved between the open and closed positions in response to a pressure change within the tank; and said piston sized smaller than said working chamber so that fluid may pass between the piston and sidewalks of the working chamber into the open section.