Patent ID: 8864105

Claim:
A floating ball valve having a pair of mounted ball-seats designed with an equilateral triangle ABC as its section outline and composed of an inner sealing ring (inner ring) and an outer supporting ring (outer ring), wherein the inner ring is of using the equilateral triangle ABC as its section outline: side AB of the triangle ABC is the ball sealing chord of the seat and at a 45 degree angle to the axis of the central bore of the ball, the surface of revolution of side BC is the sealing end surface of the seat, and the surface of revolution of side CA is the supported surface of the inner ring; the outer ring is of a trapezoid section, whose height side D′E′ is the generatrix of the cylindrical surface of the outer ring or the seat, between which and whose accommodating bore in the valve body is a clearance fit, and whose oblique side AC′ is the generatrix of the conical surface for supporting the inner ring; the ball under fluid pressure presses at the same time the outer ring and the inner ring mutually supported to make the outer ring and the inner ring be initiatively pressed to protect each other from being more pressed; the outer ring is made of higher strength material than the inner ring.