Flexible wedge gate valve

• US 6,338,469 B1
• Filed: 11/04/1999
• Issued: 01/15/2002
• Est. Priority Date: 01/22/1997
• Status: Expired due to Term

• Current Assignee: Kalsi Engineering Inc.
• Original Assignee: Kalsi Engineering Inc.
• Inventors: Kalsi, Manmohan Singh, Wang, Jaw-Kuang, Alvarez, Patricio Daniel
• Primary Examiner(s): FOX, JOHN C
• Application Number:
  US09/433,665
• Time in Patent Office: 803 Days
• Field of Search: 251/324, 251/326, 251/327
• US Class Current: 251/326
• CPC Class Codes: F16K 3/12 with wedge-shaped arrangements of sealing faces

Abstract

A wedge gate valve having a valve body defining a valve chamber and flow passages and upwardly diverging circular seat surfaces of circular, flat configuration and defining seat planes. A valve disk or wedge having downwardly converging sealing surfaces is movable within said valve chamber between open and closed positions for controlling flow through the valve. Pressure boundary plates connected by hubs to the valve disk define the sealing surfaces of the disk and have bottom corners that establish line contact with the downstream seat surface and prevent any portion of said sealing surfaces of said valve disk from crossing the sealing plane of the downstream seat in the event of flow responsive downstream movement of the valve disk during its opening and closing movement. Guide ears of the disk are provided with flexible upper and lower extremities and rounded or chamfered inner end surfaces to minimize localized peak contact stress with disk guide rails of the valve body. The center section of the disk is rendered flexible by the provision of an internal transverse cavity that extends completely through the center section or is located centrally of the center section to define flexible walls between the hubs to thus provide for disk flexibility for overcoming the tendency for disk binding. A valve actuator for opening and closing the valve disk is provided with an adjustable downstop to prevent overtravel of the disk during seating.

Claims

1. A wedge gate valve mechanism, comprising:

(a) a valve body having an internal valve chamber and flow passages intersecting said valve chamber and having planar, upwardly diverging circular seat surfaces being defined at the intersection of said valve chamber and flow passages, said valve body having guide means therein;

(b) a valve disk having a closed and fully seated position located between and in sealing engagement with said circular seat surfaces and an open position unseated from said circular seat surfaces, said valve disk comprising;

(1) a disk center section having at least one cavity located therein and defining a pair of flexible disk walls being spaced by said at least one cavity, said at least one cavity being unobstructed and said flexible disk walls being flexible at all positions of said valve disk and at said closed position of said valve disk being flexible toward one another responsive to thermal contraction of said valve body to minimize thermal binding of said valve disk, said disk center section defining top and bottom ends and having opposed sides oriented in substantially transverse relation with said flexible disk walls, said at least one cavity being located substantially centrally of said disk center section and between said opposed sides and between said top and bottom ends of said disk center section;

(2) a pair of hubs each being integrally connected with a respective one of said pair of flexible disk walls and having said cavity of said disk center section located therebetween, said pair of hubs being moveable toward one another at said closet and fully seated position of said valve disk responsive to thermal contraction of said valve body for minimizing thermal binding of said valve disk; and

(3) a pair of pressure boundary plates each being integrally connected to and supported by a respective one of said hubs and having a sealing surface thereon, said sealing surfaces of said pressure boundary plates being oriented in downwardly converging relation for sealing engagement with said upwardly diverging circular seat surfaces, said pressure boundary plates being flexible at all positions of said valve disk;

(c) disk guide means being located on opposed side portions of said valve disk and being disposed in disk guiding relation with said guide means of said valve body;

(d) a stem connection being defined by said valve disk and being disposed in offset relation with said flexible disk walls and said at least one cavity; and

(e) a valve stem having linear driving relation with said stem connection for moving said valve disk to said open and closed positions.

2. The improvement of claim 1 wherein:

said slot passing transversely through said disk center section to define said flexible walls.

3. The improvement of claim 1 wherein:

said slot being a substantially closed and unobstructed space within said disk center section.

4. A wedge gate valve mechanism comprising:

(a) a valve body having an internal valve chamber and flow passages intersecting said valve chamber and having planar, upwardly diverging circular seat surfaces being defined at the intersection of said valve chamber and flow passages, said valve body having guide means therein;

(b) a valve disk having a closed position located between and in sealing engagement with said circular seat surfaces and an open position unseated from said circular seat surfaces, said valve disk being flexible at both said open and closed positions to minimize thermal binding of said valve disk relative to said valve body under conditions where said valve disk is closed and seated and where said valve body thermally contracts more than said valve disk, said valve disk comprising;

(1) a disk center section having at least one slot of predetermined length located substantially centrally therein and defining a pair of opposed generally planar flexible disk walls being spaced by said at least one slot, said flexible disk walls being unobstructed and flexible at all positions of said valve disk and permitting movement of said opposed flexible disk walls toward one another to minimize thermal binding thereof by said valve body;

(2) a pair of hubs each being integrally connected with a respective one of said pair of flexible disk walls and having said slot of said disk center section located therebetween, said hubs having a predetermined dimension, said predetermined length of said slot of said disk center section being greater than said predetermined dimension of said hubs, said pair of hubs being moveable toward one another at said closed and fully seated position of said valve disk responsive to thermal contraction of said valve body for minimizing thermal binding of said valve disk;

(3) a pair of pressure boundary plates establishing boundary plate height length and width and being integrally connected to and supported by a respective one of said hubs and having a sealing surface thereon said length of said pressure boundary plates exceeding said predetermined length of said slot, said sealing surfaces of said pressure boundary plates being oriented in downwardly converging relation for sealing engagement with said upwardly diverging circular seat surfaces, when said valve disk is located at said closed position and fully seated said flexible disk walls and said pressure boundary plates being flexible toward one another responsive to thermal contraction of said valve body for minimizing thermal binding of said valve disk;

(c) disk guide means being located on opposed side portions of said valve disk and being disposed in disk guiding relation with said guide means of said valve body;

(d) a stem connection being defined by said valve disk and being located offset from said slot and said flexible disk walls; and

(e) a valve stem having driving engagement with said stem connection for moving said valve disk to said open and closed positions.

5. A wedge gate valve mechanism comprising:

(a) a valve body having an internal valve chamber and flow passages intersecting said valve chamber and having planar, upwardly diverging circular seat surfaces being defined at the intersection of said valve chamber and flow passages, said valve body having guide means therein, said wedge gate valve mechanism further having actuation means for opening and closing movement thereof;

(b) a valve disk having a closed position located between and in sealing engagement with said circular seat surfaces and an open position unseated from said circular seat surfaces, said valve disk comprising;

(1) a disk center section having at least one cavity located therein and defining a pair of flexible disk walls being spaced by said cavity, said disk center section defining top and bottom ends and opposed sides oriented in substantially transverse relation with said pressure boundary pressure plates; and

having opposed internal surfaces within said disk center section defining said cavity and defining said opposed internal surfaces of said flexible walls of said disk center section, said opposed internal surfaces intersecting each of said opposed sides of said disk center section and defining a transverse slot extending centrally through said disk center section and having slot openings at each of said opposed sides of said disk center section;

(2) a pair of hubs each being integrally connected with a respective one of said pair of flexible disk walls and having said cavity of said disk center section located therebetween; and

(3) a pair of pressure boundary plates each being integrally connected to and supported by a respective one of said hubs and having a sealing surface thereon, said sealing surfaces of said pressure boundary plates being oriented in downwardly converging relation for sealing engagement with said upwardly diverging circular seat surfaces, said flexible disk walls and said pressure boundary plates being movable toward said cavity responsive to thermal contraction of said valve body when said valve disk is at said closed position; and

(c) disk guide means being located on opposed side portions of said valve disk and being disposed in disk guiding relation with said guide means of said valve body.

6. The improvement of claim 5, further comprising:

said stem connection being defined by said pressure boundary plates of said valve disk and receiving said valve stem in driving relation therewith.

7. The wedge gate valve mechanism of claim 5, wherein:

said stem connection being a “

T”

-Slot adapted for driven connection with said valve stem.

8. The improvement of claim 5, wherein said flexible disk walls are of variable thickness to optimize the flexible nature thereof.