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US 4,030,520 AGranted
Ball-type safety valve
OwnerAsa D. Sandsinventor
Life of this patent
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OwnerAsa D. Sandsinventor
Estimating the term…
A safety valve has a valve body defining a valve chamber having a longitudinal axis with flow passages at opposite ends of the axis, transverse walls at opposite ends of the valve chamber separating the valve chamber from the flow passages, valve ports through the transverse walls coaxial with the valve chamber, at least one of the valve ports being defined by a frusto-conical valve seat facing the valve chamber and by a cylindrical inner surface between the valve seat and the side of the one valve port opposite the valve chamber, an annular groove formed in the cylindrical surface of the one valve port, a convolute coil spring having a large end coil seated in the annular groove and a small end axially removed from the large end in the direction of the valve chamber and located within the confines of the valve seat, a ball valve of small diameter than the valve chamber disposed in the chamber and movable toward and away from the seat, and a leak passage for bypassing a restricted flow of fluid around the valve when the valve is closed. In one embodiment of the invention both valve ports are similarly defined and both include convolute coil springs so that the valve may operate bidirectionally. In another embodiment, the valve is designed for unidirectional use, however the valve body is generally the same as in the first embodiment except that the convolute spring and seat for same are omitted from the upstream valve port, and in lieu thereof an open ended frust-conical deflector is mounted coaxially within the port so that the deflector diverges toward the valve chamber forming an annular ring of fluid which tends to center the ball valve within the valve chamber.
In a flow operated safety valve, the combination of a valve body defining a valve chamber having a longitudinal axis with flow passages at opposite ends of said axis, a cylindrical inner surface about said valve chamber, transverse walls at opposite ends of said valve chamber separating said valve chamber from said flow passages and defining annular shoulders at opposite ends of said chamber, a valve port through each of said transverse walls coaxial with said valve chamber, at least one of said valve ports being defined by a frusto-conical valve seat facing said chamber and by a cylindrical surface at the end of said valve seat remote from said chamber, an annular groove formed in said cylindrical surface of said one valve port, a convolute coil spring having a large end coil seated in said annular groove and tapering axially in the direction of said chamber to a small end located within the confines of said valve seat, a ball valve of smaller diameter than said chamber disposed in the chamber and movable toward and away from said valve seat, said safety valve body when in normal use being mounted in a flow line with its longitudinal axis horizontal so that said ball valve normally rests on the lowest portion of said cylindrical inner surface of said valve chamber out of contact with said valve seat and said spring, said ball valve being responsive to an excess rate of fluid flow above a predetermined maximum flow rate in the direction of said seat to move against said spring compressing same and seating upon said conical valve seat, thus substantially reducing the flow of fluid through said valve, and restricted leak passage means for bypassing fluid around said ball valve and said valve seat.
Dependencies are inferred from the claim text.