Patent ID: 6604544
Filing Date: 2003-08-12
Classification: F16K,Y10T

Abstract:
A safety valve installed in a tank of a vessel carrying oil or chemical substance to discharge supersaturated gas produced in the tank and to adjust an internal pressure to a normal level when a negative pressure is produced in the tank; comprising:a lower body; an upper body mounted onto the lower body; a valve stem extended from the upper body to the lower body; and a disc provided on the valve stem and positioned between the upper and lower body to shut out a communication between the upper and lower body; wherein the disc has a groove on an underside thereof, with a protruded portion being formed along an edge of the disc, a low friction material bushing is interposed between the disc and the valve stem, and the disc has a large diameter than an internal diameter of the lower body; and wherein the upper body has a straight portion on an internal lower edge thereof, the straight portion is formed in such a manner that until the disc is raised to a maximum stroke the straight portion is parallel with the disc, and a space is formed between a side of the disc and the straight straighten portion of the upper body.