Ball valve with integral seal retraction
Disclosed embodiments include ball valves with an asymmetric seal and seat, to minimize seal wear. In embodiments, a seal is disposed upon a ball with a first and second section, where the first section of the seal is disposed at a different angle from the second section. A seat has a first and second section at different angles that correspond to angles of the first and second section of the seal, respectively, such that the seal fully contacts the seat when the ball is in a closed position. When the ball is rotated to an open position, the different angles of the first and second sections allow the second section of the seal to clear the first section of the seat without contact.
1. A ball valve, comprising:
a non-planar seal disposed circumferentially upon a rotating ball, wherein the rotating ball and the non-planar seal are contained within a housing, wherein the non-planar seal comprises a first section separated from a second section by an intervening transition zone, and wherein the first section is oriented at a different angle than the second section wherein the intervening transition zone has a different angle than the first section and the second section; and
a mating surface disposed within the housing adjacent to the rotating ball, wherein the mating surface comprises a plurality of cut-outs configured to be uncovered by the non-planar seal as the rotating ball is rotated between a closed position and an open position, and wherein the plurality of cut-outs are configured to release a biasing pressure from an inlet port of the ball valve when uncovered by the non-planar seal.
2. The ball valve of claim 1 , wherein the plurality of cut-outs comprises a first subset of cut-outs disposed within the first section of the mating surface.
3. The ball valve of claim 2 , wherein the plurality of cut-outs comprises a second subset of cut-outs disposed within the second section of the mating surface.
4. The ball valve of claim 1 , wherein, when the ball valve is in the closed position, the ball valve is exposed to an upstream flow and biased towards the closed position by the upstream flow.
5. The ball valve of claim 1 , wherein the first section and the second section each comprise an arcuate portion of the non-planar seal.
6. The ball valve of claim 5 , wherein the first section, the second section, and the intervening transition zone collectively create a twist in the non-planar seal.
7. The ball valve of claim 1 , wherein the non-planar seal and the mating surface are disposed about an outlet port of the ball valve.
8. The ball valve of claim 1 , wherein the first section of the non-planar seal is oriented at a first acute angle relative to a first axis oriented tangentially to an outer surface of the rotating ball.
9. The ball valve of claim 8 , wherein the first axis is a direction of travel of the rotating ball.
10. The ball valve of claim 8 , wherein the second section of the non-planar seal is oriented at a second acute angle relative to a second axis oriented tangentially to an outer surface of the rotating ball.
11. The ball valve of claim 10 , wherein the second acute angle is greater than the first acute angle.
12. A ball valve, comprising:
a housing;
a rotating ball contained within the housing; and
a non-planar seal disposed circumferentially upon the rotating ball and contained within the housing, wherein the non-planar seal comprises a first section and a second section separated by a first intervening transition zone, and wherein the first section is oriented at a different angle than the second section such that the non-planar seal defines at least two planes, and wherein the first section, the second section wherein the first intervening transition zone has a different angle than the first section and the second section, and the first intervening transition zone collectively create a twist in the non-planar seal.
13. The ball valve of claim 12 , wherein the first section and the second section each comprise an arcuate portion of the non-planar seal.
14. The ball valve of claim 12 , wherein the first section of the non-planar seal is oriented at a first acute angle relative to a first axis oriented tangentially to an outer surface of the rotating ball.
15. The ball valve of claim 14 , wherein the first axis is a direction of travel of the rotating ball.
16. The ball valve of claim 14 , wherein the second section of the non-planar seal is oriented at a second acute angle relative to a second axis oriented tangentially to an outer surface of the rotating ball.
17. The ball valve of claim 16 , wherein the second acute angle is greater than the first acute angle.
18. A ball valve, comprising:
a non-planar seal disposed circumferentially upon a rotating ball, wherein the rotating ball and the non-planar seal are contained within a housing; and
a mating surface disposed within the housing adjacent to the rotating ball, the mating surface arranged to fully contact the non-planar seal when the ball valve is in a closed position, the mating surface including a first section and a second section on opposite sides of the mating surface, wherein the mating surface comprises a plurality of cut-outs configured to be uncovered by the non-planar seal as the rotating ball is rotated between the closed position and an open position, wherein the plurality of cut-outs comprises a first subset of cut-outs disposed within the first section of the mating surface and a second subset of cut-outs disposed within the second section of the mating surface, and wherein the first and second subset of the plurality of cut-outs are configured to release a biasing pressure from an inlet port of the ball valve when uncovered by the non-planar seal.
19. The ball valve of claim 18 , wherein the seal does not contact the mating surface until the rotating ball is rotated within five degrees of the closed position.
20. The ball valve of claim 18 , wherein, when the ball valve is in the closed position, first and second portions of the rotating ball are exposed to an upstream flow, with the first portion having a greater surface area than the second portion such that the rotating ball is biased towards the closed position when pressurized by the upstream flow.
21. The ball valve of claim 18 , wherein the seal is a first seal and the mating surface is a first mating surface, and wherein the ball valve further comprises:
a second seal; and
a second mating surface arranged to fully contact the seal when the ball valve is in a closed position.
22. The ball valve of claim 21 , wherein the first seal and first mating surface are disposed about an outlet port, and the second seal and second mating surface are disposed about an inlet port.