a vertical shock responsive fluid valve assembly capable of automatically closing a fluid valve in response to earthquake forces or other shock forces of a predetermined magnitude . the vertical shock responsive valve assembly has a flow control mechanism having a cradle that holds a movable ball in a recess at a point perpendicular in relation to a horizontal base plate , where the ball can be rotated 360 ° in any direction during seismic actions or other shock forces and rolls out of its recess at a predetermined force such that it ricochets off a housing cover covering the cradle and pushes a trip fork mechanism that is mounted on a pivoting parallelogram lever mechanism , thereby releasing a swing arm which has a disc on the end that functions as a plug for the hole in the valve body to interrupt gas or fluid flow therein .