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US 5,295,661 AGranted
Knife valve
AssigneeVelan Inc.
InventorRenald Roussel
Life of this patent
Estimating the term…
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AssigneeVelan Inc.
InventorRenald Roussel
Estimating the term…
A knife valve comprises a body defining a valve seat and a knife blade longitudinally movable by a cylindrical stem in the body for opening and closing a lateral flow passage defined therethrough. The body includes a bonnet with the stem extending therethrough and with circular packing rings being disposed therein around the stem. The valve seat is located on a first side of the blade and in operative proximity thereto. The stem includes a lower head portion which defines an angular surface, whereas a top portion of the blade defines a slot forming an angular surface parallel to the angular surface of the stem head. The stem head is engageable in the slot with the angular surfaces thereof being in sliding contact. Therefore, when the blade is in its closed position, a longitudinal force exerted by the stem on the blade is transferred into a lateral force oriented towards the seat, thereby forcing the blade against the seat in a tight bidirectional seal under a positive torque. Angular lugs provided on a lower second side of the blade cooperate with tapered lower edges of the blade to also urge the blade against the seat in its closed position. A bypass arrangement is provided in the bonnet around the stem for communication with the valve passage to prevent the pulp fibers from accumulating in the bonnet and jamming the stem. A resilient seat is mounted to the valve body on the first side of the blade.
A wafer knife gate valve comprising a body having a valve seat, a knife blade longitudinally movable by an operating means in said body for opening and closing a lateral flow passage defined through said body, a bonnet means for completely enclosing said knife blade in said valve, said bonnet means comprising therein guide means defining a cavity with said operating means being displaceable therein, a pair of chamber means being defined in said bonnet means on each side of said operating means, said bonnet means defining at an upper portion thereof a passage means at least partly around said guide means for permitting a sufficient flow between said pair of chamber means when said valve is at least partly open, whereby a substance flowing through said valve and into said bonnet means can sufficiently circulate between said pair of chamber means by way of said passage means thereby preventing solids contained in the substance from accumulating in said bonnet means and hampering the operation of the valve, wherein, in a closed position of said valve, said knife blade is seated against said valve seat for isolating the flow passage of a seat side of said valve from said bonnet means and the flow passage on a seatless side of said valve.
A knife valve comprising a body having a valve seat, a knife blade longitudinally movable by a displaceable operating means in said body for opening and closing a lateral flow passage defined through said body, a bonnet means for completely enclosing said knife blade in said valve, said bonnet means comprising therein guide means for said operating means, said valve seat being located on a first side of said knife blade and in operative proximity thereto, said operating means and said knife blade being slidably engaged one to the other and including thereat a first pair of coacting angular surfaces, a pair of lug means being provided on said body on a second side of said knife blade, said knife blade and said pair of lug means defining second and third pairs of coacting angular surfaces, said first, second and third pairs of coacting angular surfaces being adapted for transferring a longitudinal force exerted by said operating means on said knife blade when said knife blade is in a closed position thereof at least partly into lateral forces oriented towards said valve seat and acting on peripheral regions of said knife blade, whereby said knife blade is forced against said valve seat in a tight bidirectional seal.
Dependencies are inferred from the claim text.