Abstract: A packaging container having a pressure equalizing or venting valve which includes a valve seat, a pair of opposed faces and a valve opening therebetween. One of the faces is adapted to be secured to a wall of the packaging container surrounding an aperture which is located therein. A flexible valve diaphragm at least partially surrounds and substantially covers the valve opening on the other side of the faces and of the valve seat. A separation layer is secured to at least a portion of one of the faces of the valve seat and at least partially surrounds the valve opening. The separation layer is positioned between the other face and the flexible valve diaphragm to establish a pressure equalizing or venting passage extending from the valve opening through the flexible valve diaphragm.