Abstract: A seismically triggered valve is designed to shut off gas supply during an earthquake. A valve member is pivoted within a valve body, the valve member being mechanically movable to the open position. A magnet is fixed to the valve member, and a ferromagnetic ball is free on a concave surface. The center of the concave surface is aligned with the magnet; but, when the valve is shaken, the ball moves and releases the magnet. The valve member moves by gravity, but is assisted by a spring bias towards the closed position. A control rod can engage the valve member to open the valve, and can mechanically close the valve if desired. Further, a bleed passage connecting the valve body with the outlet is controlled by the control rod selectively to bleed off pressure within the valve body. The valve body is formed integrally. with an open top, and the sensor is received within the open top to close the top and properly locate the sensor.

Abstract: A seismically triggered valve is designed to shut off gas supply during an earthquake. A valve member is pivoted within a valve body, the valve member being mechanically movable to the open position and movable by gravity to the closed position. A magnet is fixed to the valve member, and a ferromagnetic ball is free on a concave surface. The center of the concave surface is aligned with the magnet; but, when the valve is shaken, the ball moves and releases the magnet so the valve member closes by gravity. The valve body is formed integrally with an open top, and the sensor is received within the open top to close the top and properly locate the sensor. The valve can be closed at will by moving the ball off center, for example by a plunger, or by magnetically attracting the ball. To prevent inadvertent closing of the valve, baffles direct the incoming fluid away from the loose edge of the valve member.