Fluid flow control device having a throttling element seal

• US 7,448,409 B2
• Filed: 03/17/2005
• Issued: 11/11/2008
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Original Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Inventors: Micheel, Raymond W., Westwater, David J.
• Primary Examiner(s): FOX, JOHN C
• Application Number:
  US11/082,265
• Publication Number:
  US 20060207666A1
• Time in Patent Office: 1,335 Days
• Field of Search: 137/625.3, 137/625.33, 137/625.37, 137/625.38, 137/625.39, 251/210
• US Class Current: 137/625.37
• CPC Class Codes: F16K 25/04 Arrangements for preventing erosion, not otherwise provided for
• CPC Class Codes: F16K 3/246 Combination of a sliding valve and a lift valve
• CPC Class Codes: F16K 47/08 for decreasing pressure or noise level and having a throttling member separate from the closure member , e.g. screens, slots, labyrinths
• CPC Class Codes: Y10T 137/86734 With metering feature
• CPC Class Codes: Y10T 137/86759 Reciprocating
• CPC Class Codes: Y10T 137/86791 Piston
• CPC Class Codes: Y10T 137/86807 Sequential opening or closing of serial ports in single flow line

Abstract

A fluid flow control device includes a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet. A valve seat ring is coupled to the body and defines an orifice through which the fluid flow path passes. A cage is also coupled to the body and defines an interior bore, wherein the cage includes at least one passage through which the fluid flow path passes. A throttling element is sized for insertion into the cage interior bore and movable along an axis between open and closed positions. The throttling element defines a sealing surface oriented substantially parallel to the axis. A seal is positioned to engage the sealing surface when the throttling element is substantially in the closed position, thereby to restrict fluid flow through the valve seat ring orifice.

Claims

1. A fluid flow control device comprising:

a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet;

a valve seat ring coupled to the body and defining an orifice through which the fluid flow path passes;

a cage coupled to the body and defining an interior bore, the cage including at least one passage through which the fluid flow path passes;

a throttling element sized for insertion into the cage interior bore and movable along an axis between open and closed positions, the throttling element defining a sealing surface oriented substantially parallel to the axis; and

a seal being positioned immediately adjacent to the valve seat ring to engage the sealing surface when the throttling element is substantially in the closed position, thereby to restrict fluid flow through the valve seat ring orifice;

and wherein the seal comprises a C-seal.

2. The fluid flow control device of claim 1, in which the throttling element sealing surface has an axial width, and in which the seal engages the sealing surface at any point along the axial width of the sealing surface.

3. A fluid flow control device comprising:

a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet;

a valve seat ring coupled to the body and defining an orifice through which the fluid flow path passes;

a cage coupled to the body and defining an interior bore, the cage including at least one passage through which the fluid flow path passes;

a throttling element sized for insertion into the cage interior bore and movable along an axis between a closed position, in which the throttling element engages the valve seat ring, and an open position, the throttling element defining a sealing surface located on an exterior perimeter of the throttling element and oriented substantially parallel to the axis; and

a seal being positioned immediately adjacent to the valve seat ring to engage the sealing surface when the throttling element is substantially in the closed position, thereby to restrict fluid flow through the valve seat ring orifice, and wherein the seal comprises a C-seal.

4. The fluid flow control device of claim 3, in which the throttling element sealing surface has an axial width, and in which the seal engages the sealing surface at any point along the axial width of the sealing surface.

5. A fluid flow control device comprising:

a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet;

a valve seat ring coupled to the body and having an orifice having a first diameter and a seat ring contact surface having a second diameter greater than the first diameter, the flow path extending through the orifice;

a cage coupled to the body and the valve seat ring, the cage defining an interior bore and including at least one passage disposed along the flow path;

a throttling element sized for insertion into the interior bore of the cage and movable along an axis between an open position in which the passage through the cage is exposed and a closed position in which the passage through the cage is closed;

the throttling element including a seating surface sized to engage the seat ring contact surface of the valve seat ring when the throttling element is in the closed position, the throttling element further including an outwardly facing sealing surface;

the cage and the seat ring cooperating to define a recess;

a seal positioned in the recess to engage the sealing surface of the throttling element when the throttling element is in the closed position

the cage, the throttling element and the seat ring define a primary leak path when the throttling element is in the closed position, the primary leak path extending between the sealing surface of the throttling element and the seal, and between the seat ring contact surface and the seating surface of the throttling element, wherein the seal is positioned to limit leakage along the primary leak path; and

wherein the seal is a C seal.

6. The fluid flow control device of claim 5, wherein the recess is formed in part by a radially inwardly facing portion of the cage.

7. The fluid flow control device of claim 5, in which the sealing surface is located on an exterior portion of the throttling element.

8. A fluid flow control device comprising:

a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet;

a valve seat ring coupled to the body and having an orifice and a seat ring contact surface, the flow path extending through the orifice;

a cage coupled to the body and the valve seat ring, the cage defining an interior bore and including at least one passage disposed along the flow path;

a throttling element having an exterior surface sized for insertion into the interior bore of the cage and movable along an axis between an open position in which the passage through the cage is exposed and a closed position in which the passage through the cage is closed;

the throttling element including an inwardly facing inner perimeter forming a seating surface sized to engage the seat ring contact surface of the valve seat ring at a point located radially outward of the orifice when the throttling element is in the closed position, the throttling element further including a sealing surface oriented generally parallel to the axis;

a recess formed at least in part by the seat ring;

a seal positioned in the recess to engage the sealing surface when the throttling element is in the closed position; and

wherein a primary leak path is formed between the seal and the sealing surface of the throttling element when the throttling element is in the closed position, and wherein at least a portion of the primary leak path is disposed radially inwardly of the exterior surface of the throttling element and radially outwardly of a diameter of the orifice.

9. The fluid flow control device of claim 8, wherein the seat ring contact surface has a diameter greater than the diameter of the orifice.

10. The fluid flow control device of claim 8, wherein the sealing surface of the throttling element is formed on a radially outwardly facing portion of the throttling element.

11. The fluid flow control device of claim 10, wherein the sealing surface of the throttling element is disposed radially inwardly of the exterior surface of the throttling element.