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US 4,510,966 AGranted
Plug valve with floating stem seal
AssigneeGarlock Inc.
InventorWilliam Parsons, Jr.
Life of this patent
Estimating the term…
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AssigneeGarlock Inc.
InventorWilliam Parsons, Jr.
Estimating the term…
An improved glandless plug valve of the type in which a tapered plug fits into a tapered bore in a valve body is provided wherein the tapers formed on the plug and in the body coact to form a body seal. A stem seal is also provided. The stem seal comprises a ring-like sealing member confined within mating grooves in the top of the plug and in a floating seal member. The floating seal member is biased downwardly to effect the seal between itself and the ring-like seal member. The bias force is transmitted to the plug valve urging it into engagement with the body of the valve, to provide a good body seal. In a preferred embodiment, the valve and plug are lined such that the valve is suitable for use in connection with corrosive liquids or slurries. The floating seal provides automatic compensation for temperature induced dimensional changes and for wear.
In a plug valve of the type comprising a tapered plug biased into engagement with a correspondingly tapered bore formed in a valve body, whereby a seal is formed between said plug and said bore, said plug being rotatable between open and closed positions by means of a stem extending out of said body, a stem seal additionally being provided, the improvement comprising said stem seal being formed by a ring seal member captured in mating annular grooves formed in said plug and in a floating seal member, said floating seal member being biased axially into engagement with said ring seal member and with said plug, whereby axial movement of said plug does not destroy said stem seal, and said ring seal member being biased radially outwardly into engagement with said floating seal member and with said plug.
An improved stem seal for a tapered plug valve comprising a ring seal member confined within mating annular grooves formed in the plug of said valve and in a floating seal means, said floating seal means being axially biased into engagement with said ring seal member, whereby axial motion of said plug may be accommodated without destruction of said stem seal,
A plug valve comprising a tapered plug fitting into a tapered bore in a valve body, said plug having a transverse passage formed therethrough for mating with inlet and outlet ports formed in said body when said valve is in the open position, said plug being rotatable by a stem extending out of said body along the axis of said tapered bore to open and close said valve, biasing means being provided to urge said plug into engagement with said tapered bore, said biasing means further urging an axially floating stem seal means into engagement with said plug, mating circumferential grooves being formed in said plug and in said floating seal means and a generally circular stem seal ring being located in said mating grooves, said seal ring being urged radially outwardly in said mating circumferential grooves by O-rings confined in each of said grooves, whereby said biasing means urges said floating seal means and said seal ring axially into engagement with said plug and said O-rings urge said seal ring radially outwardly into engagement with said plug and with said floating seal means, whereby said stem seal ring seals said plug to said floating seal means, so that axial movement of said plug with respect to said bore does not destroy the stem seal provided by said seal ring.
Dependencies are inferred from the claim text.