US3749529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plunger packing wash system
Assignee: National Oilwell Varco LP
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Filing: 1971-02-16
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Granted: 1973-07-31
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Expires: 1991-02-16
Abstract
Abstract A plunger packing wash system for a pumping mechanism for fluids containing abrasive materials in suspension therein comprising a wiping gland in the periphery of the cylinder of the pumping mechanism around the plunger, the annular clearance between the gland and the plunger being controlled so as to provide a maximum velocity flow at the surface of the plunger, at least one annular chamber in the wiping gland, open pore foam in at least one of the annular chambers, and a source of wash liquid at a pressure greater than the suction pressure of the pump communicating with the wiping gland on the intake or suction stroke of the plunger.
Inventors
- 👤 D Cornelsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:34
CPC Classifications
F; F04; F04B; F04B53/00; F04B53/16; F04B53/162; F04B53/164
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
330 words
In a pumping mechanism for pumping fluids containing abrasive materials in suspension therein having an intake and outlet mainfold provided with an intake valve and an outlet valve, at least one cylinder communicating with said manifold, a plunger axially mounted within said cylinder and movable therein between an extended position and a retracted position, said pump pulling fluid through said intake valve into said manifold and said cylinder when said plunger moves from its extended position to its retracted position and discharging fluid through said outlet valve when said plunger moves from its retracted position to its extended position, the improvement, in combination therewith, comprising a wiping gland in the periphery of said cylinder around said plunger, the annular clearance between said wiping gland and said plunger being controlled to provide a maximum velocity flow at the surface of said plunger, said wiping gland being provided with at least one annular chamber, open pore foam in at least one of said chambers contiguous with the surface of said plunger, and a source of clean wash liquid at a pressure greater than the suction pressure of said pump communicating directly with said wiping gland and said open pore foam, upstream of said open pore foam, whens said plunger moves from its extended position to its retracted position, including valve means responsive to the movement of said plunger for controlling the flow of clean wash liquid to said wiping gland, whereby said plunger is continuously wiped and cleaned both when it moves from its extended position to its retracted position, during which time clean wash liquid communicates with said wiping gland, and when it moves from its retracted position to its extended position, during which time said valve means precludes the flow of clean wash liquid to said wiping gland, and maintains a fresh charge of clean wash liquid within said annular chamber of said wiping gland, the fresh charge of clean wash liquid being slowly discharged with the fluid being pumped.
Claim 2
Dependent Claim
330 words
In a pumping mechanism for pumping fluids containing abrasive materials in suspension therein having an intake and outlet mainfold provided with an intake valve and an outlet valve, at least one cylinder communicating with said manifold, a plunger axially mounted within said cylinder and movable therein between an extended position and a retracted position, said pump pulling fluid through said intake valve into said manifold and said cylinder when said plunger moves from its extended position to its retracted position and discharging fluid through said outlet valve when said plunger moves from its retracted position to its extended position, the improvement, in combination therewith, comprising a wiping gland in the periphery of said cylinder around said plunger, the annular clearance between said wiping gland and said plunger being controlled to provide a maximum velocity flow at the surface of said plunger, said wiping gland being provided with at least one annular chamber, open pore foam in at least one of said chambers contiguous with the surface of said plunger, and a source of clean wash liquid at a pressure greater than the suction pressure of said pump communicating directly with said wiping gland and said open pore foam, upstream of said open pore foam, whens said plunger moves from its extended position to its retracted position, including valve means responsive to the movement of said plunger for controlling the flow of clean wash liquid to said wiping gland, whereby said plunger is continuously wiped and cleaned both when it moves from its extended position to its retracted position, during which time clean wash liquid communicates with said wiping gland, and when it moves from its retracted position to its extended position, during which time said valve means precludes the flow of clean wash liquid to said wiping gland, and maintains a fresh charge of clean wash liquid within said annular chamber of said wiping gland, the fresh charge of clean wash liquid being slowly discharged with the fluid being pumped.
Claim 3
Dependent Claim
35 words
The pumping mechanism according to claim 1, wherein the pressure of said clean wash liquid is sufficiently greater than the main pump suction pressure so that a positive flow of wash liquid can be achieved.
Claim 4
Dependent Claim
71 words
The pumping mechanism according to claim 1, wherein surge chamber and by-pass means are provided between said source of wash liquid and said valve means to dampen the normal pulsations resulting from the intermittent flow of wash liquid to said plunger, providing for a smoother flow of wash liquid with less chance of damage to the system and better filling of said wiping gland during the suction stroke of said pump.
Claim 5
Dependent Claim
128 words
The pumping mechanism according to claim 3, wherein said surge chamber and by-pass means comprises a supply pump communicating with said source of wash liquid, said supply pump having a greater capacity than the actual demand to insure a steady supply of said wash liquid to said valve means, a volume tank which receives the discharge from said supply pump and communicates with each of said valve means, a by-pass communicating between said volume tank and said source of supply, second valve means to control the regulation of pressure in the system leading to said valve means by varying the amount of fluid allowed to by-pass and return to said source, and at least one surge chamber disposed between said volume tank and each of said valve means.
Claim 6
Dependent Claim
33 words
The pumping mechanism according to claim 4, wherein a flow meter is disposed between said surge chamber and said volume tank to permit a reading of the amount of wash liquid being utilized.
Claim 7
Dependent Claim
24 words
The pumping mechanism according to claim 1, wherein said wiping gland is provided with two annular chambers having open pore foam in each chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |