Valve for controlling an opening for the passage of fluid into and out of a pressure accumulator

In combination with a pressure accumulator having an opening for the passage of fluid into and out of the same and an elastic membrane opposite said opening, a valve for controlling said opening, said valve comprising an elongated valve housing having an inner end provided with a valve seat and extending in a sealed manner through said opening to the outside of said pressure accumulator;

• fluid passage means communicating with the interior of the valve housing spaced from said inner end;
• a valve member movable between a closed position engaging said valve seat and an open position;
• biasing means biasing said valve member to said open position;
• a piston slidably guided in said valve housing;
• a push rod abutting with opposite ends respectively against said piston and said valve member;
• an orifice plate arranged in said valve housing between said inner end and said fluid passage means and creating during flow of fluid through said valve housing a pressure difference in the latter to opposite sides of said orifice plate;
• and channel means in said valve housing for transmitting such pressure difference to opposite sides of said piston so that the latter acts through said push rod on said valve member tending to maintain the latter in said open position during outflow of fluid from said pressure accumulator and expanding of the elastic membrane of said pressure accumulator towards said valve member.