Globe valve having a dismountable seat for rapid maintenance

• US 4,773,442 A
• Filed: 10/16/1987
• Issued: 09/27/1988
• Est. Priority Date: 09/26/1984
• Status: Expired due to Term

• Current Assignee: Schlumberger Industries Incorporated (Schlumberger NV)
• Original Assignee: Sereg
• Inventors: Lephilibert, Jean
• Primary Examiner(s): Walton, George L.
• Application Number:
  US07/110,081
• Time in Patent Office: 347 Days
• Field of Search: 137/315, 137/454.5, 137/454.6, 251/214, 251/266, 251/267, 251/275, 251/276, 251/278, 277/362, 277/363, 277/105, 277/106
• US Class Current: 137/315.28
• CPC Class Codes: F16K 1/42 Valve seats for double-seat valves F16K1/44
• CPC Class Codes: F16K 27/02 of lift valves for reducing the flow resistance of screw-spindle lift-valves F16K1/06
• CPC Class Codes: Y10T 137/6069 Having particularly packed or sealed mechanical movement actuator
• CPC Class Codes: Y10T 137/6106 Screw type
• CPC Class Codes: Y10T 137/7668 Retained by bonnet or closure

Abstract

A globe valve comprising: a control rod (70) which is movable in translation along a valve axis (XX'"'"'), handle means (90) for controlling movements of said rod in translation, a disk (74) fixed to one end of said rod; a body (12) having an inlet passage (14) and an outlet passage (16) therethrough for passing a liquid, said passages giving access to a cavity (18) which is extended via a cylindrical orifice (22) disposed along said valve axis in order to receive said rod; a cage (36) lodged inside said cavity and within which said disk is capable of being moved by axial displacement of said rod; packing (46) surrounding a portion of said rod and disposed within said cylindrical orifice; a seat (28) which is removable from said body for cooperating with said disk in a closure position, said seat having a first face defining a sealing bearing surface for cooperating with said disk and a first annular thrust bearing orifice, and a second face defining a second annular thrust bearing surface; means for defining a third annular thrust bearing surface symmetrically about said axis and disposed in said cavity between the openings to said passages and at least substantially fixed relative to said body; means (26) for providing sealing between said second and third annular thrust bearing surfaces; and compression means (50), said compression means acting on a stack having the same axis as the said valve body and comprising: said packing, said cage, said seat, and said sealing means, whereby said packing and said sealing means are subjected to said compression in order to provide sealing respectively between said rod and the wall of said cylindrical orifice through the body, and between said seat and said body.

Claims

1. A globe valve comprising:

a control rod which is movable in translation along a valve axis, handle means for controlling movements of said rod in translation, a valve disk fixed to one end of said rod;

a body constituted by a single part having an inlet passage and an outlet passage therethrough for passing a fluid to be controlled by said valve disk, said passages giving access to a cavity which is extended via a cylindrical orifice disposed along said valve axis in order to receive said rod;

a cage lodged inside said cavity and within which said valve disk is capable of being moved by axial displacement of said rod;

packing surrounding a portion of said rod and disposed within said cylindrical orifice, said packing being in contact with said rod and the wall of said cylindrical orifice and being supported by said cage;

a seat which is removable from said body for co-operating with said valve disk in a closure position, said seat having a first face defining a sealing bearing surface for co-operating with said valve disk and a first annular thrust bearing surface, and a second face defining a second annular thrust bearing surface;

means for defining a third annular thrust bearing surface symmetrically around said valve axis and disposed in said cavity between the opening of said passages and at least substantially fixed relative to said body, said second and third annular thrust bearing surfaces being inclined with respect to said valve axis;

means for providing sealing directly between said second and third annular thrust bearing surfaces, said sealing means and said second and third thrust bearing surfaces cooperating together to provide a substantially complete axial and radial seal between said second and third thrust bearing surfaces, the size of said cage, said seat, and said sealing means being less, in planes perpendicular to said valve axis, than the diameter of said cylindrical cavity; and

compression means, said compression means acting on a stack having the same axis as said valve and consisting in;

said packing, said cage, said seat, and said sealing means, whereby said packing and said sealing means are both subjected to said compression in order to provide sealing respectively between said rod and said wall of the cylindrical orifice, and between said seat and said body, and whereby said packing may be removed from said body by said cage, said valve disk and said rod being movable by axial displacement of said rod so that said seat may be serviced.

2. A globe valve according to claim 1, wherein said body is constituted by a single part, and wherein the size of said cage, said seat, and said sealing means is less, in planes perpendicular to the axis of said valve, than the diameter of said orifice extending said cavity provided inside the valve body.

3. A globe valve according to claim 1, wherein said means for forming said third annular thrust bearing surface are constituted by a shoulder on said body inside said cavity, and wherein said sealing means comprise a gasket interposed between said second and third annular thrust bearing surfaces.

4. A globe valve according to claim 3, wherein said cage is formed by a base having an orifice therethrough to pass said rod and a side wall having orifices therethrough for passing the liquid, said valve disk being capable of sliding therein, said side wall including a free edge at the opposite end from said base, said edge being applied against said first annular thrust bearing surface, and said packing resting on the outer face of said base.

5. A globe valve according to claim 4, wherein said compression means comprises a plate having an orifice for passing said rod, means for fixing said plate to said body, a stack of resilient washers surrounding said rod, and a packing ram surrounding said rod, said resilient washers being interposed between said plate, and said packing ram, and said packing ram being interposed between said resilient washers and said packing.

6. A globe valve according to claim 4, wherein said means for fixing said plate comprise at least two tiebars disposed parallel to said control rod and each having a first end fixed to a flange which is an integral part of said valve body, a threaded middle portion passing through holes provided in said plate, and at least two nuts, each nut being in contact with that face of said plate which is not in contact with said resilient washers.

7. A globe valve according to claim 1, wherein said means for forming said third annular thrust bearing surface are constituted by a shoulder in said body inside said cavity, and wherein said sealing means comprise ribs provided in said second annular bearing surface of said seat.

8. A globe valve according to claim 1, and further comprising a second cage lodged in a second cavity provided in said valve body, said second cavity communicating with said cavity via a cylindrical passage, said second cage having a free edge disposed in said cylindrical passage an forming said third annular thrust bearing surface, wherein said sealing means comprise an annular gasket lodged in said cylindrical pasage and resting on said free edge.

9. A globe valve according to claim 8, in which said second cage includes a base at the opposite end to said free edge, said base of said second cage resting against a wall of said second cavity via a resilient system.

10. A globe valve according to claim 1, wherein the means for creating said third thrust bearing surface are fixed relative to said valve body, said valve further comprising means for providing a fourth thrust bearing surface which is fixed relative to said valve body so that said seat abuts against said fourth thrust bearing surface under the effect of the compression means, whereby compression of the sealing means between said second and third thrust bearing surfaces is limited by the co-operation between said seat and said fourth thrust bearing surface.