Steel ball valve

• US 5,169,123 A
• Filed: 12/18/1991
• Issued: 12/08/1992
• Est. Priority Date: 04/28/1989
• Status: Expired due to Fees

• Current Assignee: Vanatome Societe Anonyme
• Original Assignee: Vanatome Societe Anonyme
• Inventors: Martin, Roger, Buffa, Laurent
• Primary Examiner(s): Fox, John C.
• Application Number:
  US07/810,356
• Time in Patent Office: 356 Days
• Field of Search: 251/172, 251/160
• US Class Current: 251/177
• CPC Class Codes: F16K 39/06 for taps or cocks
• CPC Class Codes: F16K 5/205 Sealing effected by the flowing medium

Abstract

A valve, with a ball having a shaft (5), comprises, at least on the "upstream" side, a seat (14) that can move in the direction in which the fluid flows (F). Seat (14) is connected to body (1) of the valve by an annular membrane (21), constituting a wall of an annular chamber (22) relatively isolated from the "upstream" conditions for example, by a calibrated hole (23). Equilibration means (26) are provided, with a channel (28) and a conduit (29) connecting annular chamber (22) to central volume (27) of the valve, a communication being formed when the valve is opened, thus moving seat (14) away from ball (5). Said communication can be caused to form by control rod (10) of ball (5) when the valve is adjusted for opening.

Claims

1. A steel ball valve of the type having a shaft, wherein a ball (5) is mounted inside a body (1) of the valve and comprises a central passage (6) and is guided in rotation in bearings (8, 9) and is connected to control means (10 to 13) designed to cause it to pivot around an axis (7) between a closed position and an open position wherein the fluid can flow in the direction of an axis (4) perpendicular to the rotation axis (7) of the ball (5), through the central passage (6) in said ball (5), said valve comprising at least on an upstream side with reference to the direction (F) in which the fluid is flowing, a seat (14) mounted to move in the direction of the axis (4) along which said flow occurs, said seat (14) being connected to the body (1) of the valve by an annular membrane (21) and first means for assuring equilibration of pressure of the fluid on both sides of said seat (14) when the valve is being opened and second means (36) for relieving the equilibration when the valve is being closed, wherein said first equilibration means comprise at least on the upstream side an annular chamber (22) one wall of which is composed of the aforementioned annular membrane (21) and which is relatively isolated (23, 24) from the upstream conditions, and means (26) for forming a temporary communication between said annular chamber (22) and a central volume (27d) of the valve, which houses said ball (5),

wherein said valve is provided with at least one first spring (17) acting on said seat (14) to move it away from said ball (5);

wherein a scraper joint (16) is mounted inside said seat (14) and is kept in contact with said ball (5) regardless of the position of said seat (14) under the effect of the thrust of at least one second spring (20) acting in an opposite direction of said first spring (17).

2. The steel ball alve according to claim 1, wherein said annular chamber (22) is relatively isolated from the upstream conditions by at least one calibrated hole (23) placed radially in said scraper joint (16).

3. The steel ball valve according to claim 1, wherein said annular chamber (22) is relatively isolated from the upstream conditions by a radial clearance (24) provided between said scraper joint (16) and said body (1) of the valve.

4. The steel ball valve according to claim 1, wherein said annular chamber (22) has a relatively small volume.

5. The steel ball valve according claim 1, wherein said upstream seat (14) and a downstream seat (36) are each mounted to move in the direction of the axis (4) along which the fluid flows, wherein each seat (14, 36) is associated with a membrane (21) and with an annular chamber (22) that is relatively isolated from the upstream and downstream conditions, depending on the case, and wherein said means of forming the communication (26) connects the central volume (27) of the valve with both of the annular chambers (22), said communication being formed selectively.

6. The steel ball valve according to claim 5, wherein each of the upstream (14) and downstream (36) seats are equipped with a counter-membrane (38) in addition to the aforementioned membrane (21).

7. A steel ball valve of the type having a shaft, wherein a ball (5) is mounted inside a body (1) of the valve and comprises a central passage (6) and is guided in rotation in bearings (8, 9) and is connected to control means (10 to 13) designed to cause it to pivot around an axis (7) between a closed position and an open position wherein the fluid can flow in the direction of an axis (4) perpendicular to the rotation axis (7) of the ball (5), through the central passage (6) in said ball (5), said valve comprising at least on an upstream side with reference to the direction (F) in which the fluid is flowing, a seat (14) mounted to move in the direction of the axis (4) along which said flow occurs, said seat (14) being connected to the body (1) of the valve by an annular membrane (21) and first means for assuring equilibration of pressure of the fluid on both sides of said seat (14) when the valve is being opened and second means (36) for relieving the equilibration when the valve is being closed, wherein said first equilibration means comprise at least on the upstream side an annular chamber (22) one wall of which is composed of the aforementioned annular membrane (21) and which is relatively isolated (23, 24) from the upstream conditions, and means (26) for forming a temporary communication between said annular chamber (22) and a central volume (27d) of the valve, which houses said ball (5);

wherein said means (26) for forming the communication between said annular chamber (22) and said central volume (27) comprise at least one internal channel (28) and/or one conduit (29), with a closure (33) activated directly by the control means (10 to 13,

     31) of said ball (5), when opening is initiated and when closing is completed.

8. The steel ball valve according to claim 7, wherein said control rod (1) of said ball (5) comprises a cam (31) that cooperates with a tappet (32) which itself acts on a mobile closure (33).

9. The steel ball valve according to claim 8, wherein aid mobile closure (33) is in the form of a pin subjected to the effect of a spring (34) inserted in channel (28) and/or conduit (29) forming the communication between said annular chamber (22) and said central volume (27).

10. The steel ball valve according to claim 9, wherein said tappet (32) is mounted to slide in a tubular conduit (29) issuing into said central volume (27) through at least one orifice (30) and communicating through at least one hole (35) designed to be blocked or unblocked by said mobile closure (33, with said channel (28) issuing into said annular chamber (22).

11. The steel ball valve according to claim 7, wherein said annular chamber (22) is relatively isolated from the upstream conditions by at least one calibrated hole (23) placed radially in said scraper joint (16).

12. The steel ball valve according to claim 7, wherein said annular chamber (22) is relatively isolated from the upstream conditions by a radial clearance (24) provided between said scraper joint (16) and said body (1) of the valve.

13. The steel ball valve according to claim 7, wherein said annular chamber (22) has a relatively small volume.