Fluid end with carbide valve seat and adhesive dampening interface

{
  "publication_number": "US9435454B2",
  "country": "US",
  "kind": "B2",
  "title": "Fluid end with carbide valve seat and adhesive dampening interface",
  "abstract": "A tungsten carbide seat for high-pressure oilfield well service pumps is disclosed. A bonding agent, in conjunction with an interference tapered fit between the valve seat and fluid end housing eliminates stresses created in prior art interference fits. Three interface embodiments are disclosed: a shallow taper combined with a shoulder, a steep taper without a shoulder, and a compound surface in which the seat has an external concave surface and the housing surface that mates with the seat has a convex surface.",
  "claims": [
    "1. A fluid end assembly comprising: a fluid end housing; a valve body; a valve seat, wherein said valve seat is formed with a cemented tungsten carbide; wherein: said valve body comprises a first mating surface configured to be received in a nested position against a second mating surface on said valve seat in response to compressive fluid pressure; said valve seat further comprises a third mating surface that is secured by a bonding agent to a fourth mating surface on said fluid end housing, wherein said third and fourth mating surfaces comprise first and second complementary tapers, respectively, and wherein said bonding agent is evenly distributed between said third and fourth tapered mating surfaces by pressure applied to said valve seat during insertion of said valve seat into said fluid end housing; and said bonding agent is operable to absorb a portion of said compressive fluid pressure on said valve body when said valve body is compressed in said nested position by said compressive fluid pressure.",
    "2. The fluid end assembly of claim 1 wherein said epoxy bonding agent comprises layer of epoxy between said third and fourth mating surfaces, said layer having a thickness of between 0.001 and 0.010 inches.",
    "3. The fluid end assembly of claim 2, wherein said layer of epoxy is formed by a method comprising: applying a layer of epoxy between said third and fourth mating surfaces, said layer having an initial thickness in excess of 0.010 inches; applying pressure to squeeze a portion of said layer of epoxy out of the space between said third and fourth mating surfaces to form a layer of epoxy having a thickness of between 0.001 and 0.010 inches.",
    "4. A fluid end assembly of claim 1 in which the interface angle between said third mating surface of said seat and said fourth mating surface of said housing does not exceed 2.5 inches taper per foot on the diameter.",
    "5. The fluid end assembly of claim 1 in which the interface angle between said third mating surface of said seat and said fourth mating surface of said housing exceeds 2.5 inches taper per foot on the diameter.",
    "6. A fluid end assembly of claim 5, wherein the interface between said fluid end housing and said valve seat further includes and internal shoulder in said fluid housing that shoulders with the bottom of the valve seat.",
    "7. The fluid end assembly of claim 1, wherein said bonding agent comprises cured epoxy bonding agent.",
    "8. The fluid end assembly of claim 7, wherein said epoxy bonding agent comprises a multi-part adhesive.",
    "9. The fluid end assembly of claim 7, wherein said epoxy bonding agent comprises a single-part adhesive.",
    "10. A fluid end assembly of claim 1 wherein the interface between said fluid end housing and said valve seat further includes and internal shoulder in said fluid housing that shoulders with the bottom of the valve seat.",
    "11. The fluid end assembly of claim 10 wherein said valve seat is formed with a tungsten carbide.",
    "12. The fluid end assembly of claim 10, wherein said bonding agent comprises cured epoxy bonding agent.",
    "13. The fluid end assembly of claim 12 wherein said epoxy bonding agent comprises layer of epoxy between said third and fourth mating surfaces, said layer having a thickness of between 0.001 and 0.010 inches.",
    "14. The fluid end assembly of claim 12, wherein said layer of epoxy is formed by a method comprising: applying a layer of epoxy between said third and fourth mating surfaces, said layer having an initial thickness in excess of 0.010 inches; applying pressure to squeeze a portion of said layer of epoxy out of the space between said third and fourth mating surfaces to form a layer of epoxy having a thickness of between 0.001 and 0.010 inches.",
    "15. A fluid end assembly comprising: a fluid end housing; a valve body; a valve seat, wherein said valve seat is formed with a cemented tungsten carbide; wherein: said valve body comprises a first mating surface configured to be received in a nested position against a second mating surface on said valve seat in response to compressive fluid pressure; said valve seat further comprises a third convex mating surface that is secured by a bonding agent to a fourth concave mating surface on said fluid end housing, wherein said third convex mating surface and fourth concave mating surfaces comprise first and second complementary tapers, respectively, and wherein said bonding agent is evenly distributed between said third convex mating surface and said fourth concave mating surface by pressure applied to said valve seat during insertion of said valve seat into said fluid end housing; and said bonding agent is operable to absorb a portion of said compressive fluid pressure on said valve body when said valve body is compressed in said nested position by said compressive fluid pressure."
  ],
  "description_excerpt": "The invention relates generally to methods for installing and assembling tungsten carbide seats in fluid ends used in high pressure oilfield well service pumps.\n\nThe statements in this background section merely provide background information related to the present disclosure and may not constitute prior art.\n\nEngineers typically design high-pressure oil field plunger pumps in two sections; the (proximal) power section and the (distal) fluid section. The power section usually comprises a crankshaft, reduction gears, bearings, connecting rods, crossheads, crosshead extension rods, etc. The power section is commonly referred to as the power end by the users and hereafter in this application. The fluid section is commonly referred to as the fluid end by the users and hereafter in this application. Commonly used fluid sections usually comprise a plunger pump housing having a suction valve in a suction bore, a discharge valve in a discharge bore, an access bore, and a plunger in a plunger bore, plus high-pressure seals, retainers, etc. FIG. 1 is a cross-sectional schematic view of a typical fluid end showing its connection to a power end by stay rods. FIG. 1 also illustrates a fluid chamber which is one internal section of the housing containing the valves, seats, plungers, plunger packing, retainers, covers, and miscellaneous seals previously described. A plurality of fluid chambers similar to that illustrated in FIG. 1 may be combined, as suggested in the Triplex fluid end housing schematically illustrated in FIGS. 2A-D.",
  "cpc": [
    "F16K 25/005",
    "F04B 53/007",
    "F04B 53/1032",
    "F04B 53/1087",
    "F04B 53/16",
    "F04B 53/164",
    "F16K 1/42",
    "F16K 15/063"
  ],
  "ipc": [
    "F16K 25/00",
    "F04B 53/00",
    "F04B 53/10",
    "F04B 53/16",
    "F16K 1/42",
    "F16K 15/06"
  ],
  "inventors": [
    "George H Blume"
  ],
  "filing_date": "2013-08-30",
  "publication_date": "2016-09-06",
  "grant_date": "2016-09-06",
  "priority_date": "2009-02-23",
  "application_number": "US-201314014594-A",
  "family_id": "50232292",
  "cited_by_count": 113,
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}