Seal Assembly for a Fluid Pressure Control Device

• US 20090309059A1
• Filed: 08/24/2009
• Published: 12/17/2009
• Est. Priority Date: 11/10/2004
• Status: Active Grant

• Current Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Original Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Inventors: Catron, Frederick W., McCarty, Michael W., Bush, Donald R., Adams, Daniel M., Frohwein, Michael D.
• Granted Patent: US 8,550,117 B2
• Time in Patent Office: Days
• US Class Current: 251/363
• CPC Class Codes: F16K 1/34 Cutting-off parts, e.g. valve members, seats F16K1/06, F16K1/12, F16K1/14, F16K1/26 take precedence
• CPC Class Codes: F16K 3/246 Combination of a sliding valve and a lift valve
• CPC Class Codes: F16K 3/267 Combination of a sliding valve and a lift valve F16K3/262, F16K3/265 take precedence
• CPC Class Codes: F16K 39/022 using balancing surfaces
• CPC Class Codes: Y10T 137/86734 With metering feature
• CPC Class Codes: Y10T 137/86759 Reciprocating
• CPC Class Codes: Y10T 137/86791 Piston

Abstract

A seal assembly for a fluid pressure control device includes a guide element having a sealing surface and a first guide surface. A throttling element assembly includes a throttling element positionable within a fluid flow path, the assembly defines a mating surface adapted to seal with the sealing surface, and a second guide surface sized to slidingly engage the first guide surface. A relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces to receive loose solid material, to thereby prevent disruption of the seal formed between the sealing surface and the mating surface.

Claims

1. A seal assembly for a fluid pressure control device having a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet, the seal assembly comprising:

a guide element coupled to the body and comprising a packing assembly defining a sealing surface and a first guide surface; and

a throttling element assembly comprising a throttling element positionable within the flow path and a stem coupled to the throttling element, the stem having an exterior surface defining a mating surface and a second guide surface, the mating surface adapted to seal with the sealing surface of the guide element, the second guide surface sized to slidingly engage the first guide surface of the guide element;

wherein a relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces.

2. The seal assembly of claim 1, wherein the sealing surface and the first guide surface are defined by a same interior surface of the packing assembly, and wherein the mating surface and the second guide surface are defined by a same portion of the stem exterior surface.

3. The seal assembly of claim 1, wherein the relief void is formed in an upper portion of a bearing ring.

4. The seal assembly of claim 1, wherein the bearing ring is separated from the packing assembly by a neck formed in a portion of a valve bonnet.

5. The seal assembly of claim 4, wherein the bearing ring is disposed in a countersunk receptacle.

6. A seal assembly for a fluid pressure control device having a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet, the seal assembly comprising:

a valve bonnet comprising a bore, a packing chamber, a neck, and a receptacle;

a valve stem extending through the valve bonnet and having an outer surface;

a packing assembly disposed in the packing chamber and defining a sealing surface arranged to engage a first portion of the outer surface of the valve stem;

a bearing ring disposed in the receptacle and forming a guide surface positioned to guide a second portion of the outer surface of the valve stem;

a relief void formed in a portion of the bearing ring adjacent the second portion of the outer surface of the valve stem.

7. The seal assembly of claim 6, wherein the bearing ring and the packing assembly are separated by the neck.

8. The seal assembly of claim 6, wherein the relief void is formed in an upper portion of the bearing ring.

9. The seal assembly of claim 6, wherein the bearing ring is separated from the packing assembly by the neck, and wherein the relief void is formed immediately adjacent the neck.

10. The seal assembly of claim 6, wherein the receptacle is formed by a bore countersunk into the bore through the valve bonnet.