Fluid control ball valve structure for throttling service

Claim 2

A fluid control ball valve structure comprising a valve body having a valvE chamber, upstream and downstream flow passages formed in said valve body and being in fluid communication with the valve chamber, a ball member disposed within the valve chamber and having a bore therethrough, means to rotate the ball member about a fixed axis of rotation between an open position in which the bore is in axial alignment with the flow passages and a closed position in which the bore is positioned generally at a right angle to the flow passages, an annular upstream seat member about the upstream flow passage and an annular downstream seat member about the downstream flow passage, the bore through said ball member having an entrance port adjacent the upstream seat member and an exit port adjacent the downstream seat member, and a circumferential upstream edge portion on said ball member defining the entrance port and having a generally arcuate indentation therein positioned on the circumferential segment of the edge portion initially clearing the upstream seat member upon rotation of the ball member from fully closed position toward open position, said arcuate indentation being struck from a generally constant radius which is positioned generally along a horizontal plane extending through the centerline of the flow passage with the surface formed by the indentation being beveled along its lateral edges, said indentation upon being exposed initially to fluid flow increasing substantially the flow area upon the initial opening of the valve member.

Claim 3

A fluid control ball valve structure as set forth in claim 1 wherein said bore increases progressively in diameter from the entrance port to the exit port.

Claim 4

A fluid control ball valve structure as set forth in claim 1 wherein a downstream circumferential edge portion defines the exit port of said bore and has an arcuate indentation positioned on a segment thereof initially clearing the downstream seat member upon rotation of the ball member from fully closed position toward open position thereby to permit exit of the fluid initially received through the flow area defined by said arcuate indentation on the upstream edge portion.

Claim 5

A fluid control ball valve structure as set forth in claim 1 wherein said arcuate indentation extends for at least thirty degrees of the circumference of said edge portion to a maximum of one hundred and eighty degrees.

Claim 6

A fluid control ball valve structure comprising a valve body having a valve chamber, upstream and downstream flow passages formed in said valve body and being in fluid communication with the valve chamber, a valve ball member disposed within the valve chamber and having a bore therethrough, means to rotate the ball member about a fixed axis of rotation between an open position in which the bore is in axial alignment with said flow passages and a closed position in which the bore is positioned generally at a right angle to the flow passages, an annular upstream seat member about the upstream flow passages and an annular downstream seat member about the downstream flow passage, the bore through said ball member having an entrance port adjacent the upstream seat member and an exit port adjacent the downstream seat member, and opposed circular circumferential edge portions of said ball member defining the entrance and exit ports and each edge portion having a generally arcuate groove therein for at least thirty degress of its circumference positioned on the circumferential segment of the respective edge portion initially clearing the adjacent seat member upon rotation of the ball member from fully closed position toward an open position, said arcuate grooves being struck from generally constant radii positioned generally along a horizontal plane extending through the centerline of the flow passage with the surfaces formed by the grooves being beveled along their lateral edges, said grooves upon being exposed initially to fluid flow increasing substantially the flow area upon the initial opening of the valve ball member.

Claim 7

A fluid control ball valve structure comprising a valve body having a valve chamber, upstream and downstream flow passages formed in said valve body and being in fluid communication with the valve chamber, a valve ball member disposed within the valve chamber and having a bore therethrough, means to rotate the ball member about a fixed axis of rotation between an open position in which the bore is in axial alignment with said flow passages and a closed position in which the bore is positioned generally at a right angle to the flow passages, an annular upstream seat member about the upstream flow passages and an annular downstream seat member about the downstream flow passage, the bore through said ball member having an entrance port adjacent the upstream seat member and an exit port adjacent the downstream seat member, and opposed circular circumferential edge portions of said ball member defining the entrance and exit ports and each edge portion having a generally arcuate groove therein for at least thirty degress of its circumference positioned on the circumferential segment of the respective edge portion initially clearing the adjacent seat member upon rotation of the ball member from fully closed position toward an open position, said arcuate grooves being struck from generally constant radii positioned generally along a horizontal plane extending through the centerline of the flow passage with the surfaces formed by the grooves being beveled along their lateral edges, said grooves upon being exposed initially to fluid flow increasing substantially the flow area upon the initial opening of the valve ball member.