Pressure equalizing flapper type safety valve for subterranean wells

摘要

The disclosure relates to a flapper type safety valve incorporating a pressure equalizing feature in the body of the flapper valve. A bypass aperture in the flapper valve communicates with a downwardly facing conical sealing surface. A conically shaped sealing plug is insertable in the bypass aperture and has a post portion projecting upwardly through such aperture. A diametral slot is provided in the top surface of the flapper valve body to mount a leaf spring which is secured to the upstanding post. An abutment element is also secured to the top end of the upstanding post and projects diametrically into the path of the actuating sleeve normally utilized to effect the opening of the flapper valve. The actuating sleeve thus contacts the abutment element prior to effecting any opening movement of the flapper valve and depresses the abutment element downwardly, against the bias of the leaf spring, to move the sealing plug downwardly and open the bypass aperture, thus equalizing pressure across the flapper valve body before any opening movement of the flapper valve body occurs.