Mono-seat gate valve

• US 4,294,427 A
• Filed: 07/19/1979
• Issued: 10/13/1981
• Est. Priority Date: 07/19/1979
• Status: Expired due to Term

• Current Assignee: Eugene J. Cilny
• Original Assignee: Eugene J. Cilny
• Inventors: Cilny, Eugene J.
• Primary Examiner(s): Weakley, Harold W.
• Application Number:
  US06/059,251
• Time in Patent Office: 817 Days
• Field of Search: 251/86, 251/158, 251/194, 251/330, 251/333
• US Class Current: 251/86
• CPC Class Codes: F16K 3/10 with special arrangements for separating the sealing faces or for pressing them together
• CPC Class Codes: F16K 3/14 with special arrangements for separating the sealing faces or for pressing them together

Abstract

A single valve element disc and seat gate valve has an in-line flow passage therethrough. The valve seat plane is inclined approximately 5° from the valve stem. First and second cam surfaces are positioned outside the flow passage, and are inclined approximately 30° from the stem axis so that the cam surfaces and the valve seat plane define a wedge for receiving the valve disc and a hanger supporting the disc.

The valve seat is a frustoconical surface. The valve disc is fixed to the hanger by means for urging the valve disc against the seat at the center thereof in a manner to ensure an effective seal therebetween. The gate valve includes a back seal for permitting the stem seal to be removed and replaced while the valve remains in service.

Claims

1. A gate valve comprising:

(a) a valve body formed to define inlet and outlet passages having a common axis, said valve body further defining a transverse axis being substantially normal to said common axis, said valve body defining an annular seat about at least one of said inlet and outlet passages, said seat lying in a plane that is inclined at a first angle with respect to said transverse axis, said seat being formed to define a frusto conical annular sealing surface, said sealing surface being generated about an axis disposed in normal relation to said inclined plane, said body defining first and second cam action surfaces inclined at a second angle with respect to said transverse axis in a direction opposite that of the plane of said valve seat, said cam action surfaces being positioned outside of the flow passage defined by said inlet and outlet passages and respectively above and below said flow passage, and a second body section defining a valve chamber communicating with said inlet and outlet passages;

(b) a bonnet cooperating with said second body section to further define said valve chamber;

(c) a closure member, comprising;

(1) a hanger forming a front surface defining a plane, said plane inclined at said first angle with respect to a central axis of said hanger, and having a mounting hole therethough normal to said front surface plane, and having a vertically oriented arcuate member positioned on each side of said mounting hole adjacent thereto, said hanger further defining first and second cam action surfaces for engaging respective body first and second cam action surfaces, each of said hanger cam action surfaces inclined at said second angle with respect to said central axis;

(2) a valve disc defining a plane and having a mounting shaft formed at the geometric center thereof normal to said valve disc plane, said valve disc being carried and retained solely by said hanger in a spaced relation to said valve body in a manner to permit limited universal movement of said disc with respect to said hanger about an axis passing through said mounting hole normal to said hanger front surface plane, and positioned so that said disc plane is essentially parallel to said valve seat plane, said valve disc permitted to pivot about said mounting hole axis sufficiently to engage said valve seat and effect a uniform seal therebetween to preclude fluid flow through said passage; and

(3) a valve stem having an axis coincident with said valve body transverse axis, said stem extending through said bonnet and valve chamber and carrying said hanger by a means permitting limited movement of said hanger with respect to said stem in a plane normal to said stem axis, said stem threadedly engaging said bonnet for raising and lowering said hanger and said valve disc with respect to said body flow passage;

(d) an annular seal positioned within said bonnet and about said stem for precluding the escape of medium fluid therebetween; and

(e) a back seal formed by said stem and said bonnet when said stem is in its uppermost position for sealing said valve chamber to permit said annular seal to be removed and replaced while said valve remains in service,

whereby lowering said stem and said hanger causes said hanger respective first and second cam action surfaces to engage respective first and second valve body cam action surfaces, thereby causing an axial force along said valve stem to be transmitted through said vertically oriented arcuate members to the geometric center of said valve disc in a direction essentially normal to said valve seat plane for urging said valve disc into sealing engagement with said valve seat to preclude fluid flow through said body flow passage.

2. The gate valve as set forth in claim 1, wherein said second angle is greater than said first angle.

3. The gate valve as set forth in claim 2, wherein said first angle is within the range of 0°

-10° and

wherein said second angle is within the range of 15°

-45°

.