Patent ID: 6725661
Filing Date: 2004-04-27
Classification: F02B,F02D,F02M,Y02T

Abstract:
Valve device for evacuation of a gaseous medium with a pressure above atmospheric pressure from a space (3), comprising an atmosphere-communicating valve housing (1) with a valve opening (2) to said space, a valve body (6) which is biased towards the closed position in contact with a valve seat (5) about the valve opening by spring elements (17) and towards the open position by the pressure of the gaseous medium, and a control plunger (13) disposed in a cylinder (12), said plunger, upon supply of a control pressure medium to a cylinder chamber on its one side, being loaded by a force which counteracts the spring force, characterized in that the plunger (13) and the valve body (6) are movable relative to each other and are biased in opposite directions by the control pressure medium, that first spring means (17) bias, via the plunger, the valve body towards the closed position, that second spring means (11) bias the valve body towards the open position, and that the spring forces of the first and second spring elements and the plunger area and the area of the valve body exposed to the gaseous medium, are selected so that the first spring means, in the absence of control pressure medium, keeps the valve body in the closed position until a predetermined maximum pressure has been reached in said space, and that the valve body, upon supply of control pressure medium with a pressure within a predetermined pressure interval, opens the valve to maintain a gas medium pressure dependent on the control pressure within an interval, the upper limit of which is lower than said maximum pressure.