A high-pressure butterfly valve having pressure enhanced sealing which comprises a valve body defined by a pair of interfitting body plates that are retained in assembly by bolts that also secure the valve mechanism into a flow line. The interfitting valve plates also cooperate to define a seal recess within which is received an annular sealing element that provides a peripheral seal about a butterfly disc that is rotatably supported within a flow passage defined by the valve body plates. The annular sealing element also includes a pressure-responsive portion that is energized by pressure upstream of the butterfly element and which is directly responsive to pressure to urge the sealing portion thereof into sealing engagement with the periphery of the butterfly element. The valve body is so constructed that the downstream plate thereof may be secured in assembly with the upstream plate by bolts extending through an upstream pipe flange, thereby allowing the valve mechanism to be employed in the absence of any abutting relationship with a downstream pipe flange. The pressure enhancing feature of the annular sealing element also induces pressure enhanced sealing about a valve stem and trunnion that support the butterfly element for rotation within the flow passage of the valve.
A valve comprising a substantially cylindrical housing, a substantially annular cylindrical resilient valve seating member in said housing, said seating member having an inner surface and an outer surface, a butterfly valve having an outer periphery, a shaft extending through the housing and the seating member for mounting the butterfly valve for movement between a first position wherein its outer periphery is in engagement with the inner surface of the seating member and an open position wherein the outer periphery of the butterfly valve is spaced from the inner surface, a plurality of ribs on the outer surface of the valve seating member for bearing against the inner surface of the housing, chambers between the ribs, a plurality of openings in the valve seating member upstream of the butterfly valve for permitting pressurized fluid to enter the chambers to thereby tend to move the resilient valve seating member radially inwardly into engagement with the outer periphery of the butterfly valve when the latter is in a closed position, said ribs limiting said seating member from expanding outwardly.
A valve comprising a substantially cylindrical housing, a substantially annular cylindrical resilient valve seating member in said housing, said seating member having an inner surface and an outer surface, a butterfly valve having an outer periphery, a shaft extending through the housing and the seating member for mounting the butterfly valve for movement between a first position wherein its outer periphery is in engagement with the inner surface of the seating member and an open position wherein the outer periphery of the valve is spaced from the inner surface, an annular chamber between the outer surface of the valve seating member and the housing, a plurality of apertures in the valve seating member upstream of the butterfly valve for permitting pressurized fluid to enter the chamber to thereby tend to move the resilient valve seating member radially inwardly into engagement with the outer periphery of the butterfly valve when the latter is in a closed position.
An expansible device for exerting force which has a generally "S" shape cross-section, being formed by stepped diameter cylinder, and arrangements using such a device are disclosed. The device may exert sealing forces and be controlled by admission of fluid pressure which acts on a thin wall member so supported as to be subjected to compressive stress alone.
A butterfly valve for use with corrosive fluids is constructed of fiberglass-reinforced plastic (FRP). The valve blade is mounted in the valve body on a shaft comprising a continuous strand fiberglass-reinforced plastic rod secured in a sleeve. Exposed end portions of the rod are coated with plastic resin and machined for journaling in the valve body. An FRP sealing layer coats the sleeve and adjacent portion. A pressurizeable O-ring seal surrounds the passageway of the valve body for sealing against the periphery of the blade. The periphery of the blade is rounded and sized so that the O-ring cups the periphery of the blade when closed. The valve body is formed in two tubular sections which are connected together during assembly of the valve. The end faces of the two sections are oppositely beveled to jointly form an inverted V-shaped channel for the O-ring seal. The beveled end faces provide acutely angled edges tangentially contacting the sides of the O-ring along the inner surface of the valve body. During assembly, the O-ring is positioned between the beveled faces and fiberglass-reinforced plastic putty is laid in the channel along the exterior lateral sides of the O-ring to form wedges to retain the O-ring in position. An exterior overlay of fiberglass-reinforced plastic is then applied across the channel to connect the two sections together to form a unitary valve body.
An expansible device for exerting force which has a generally "S" shape cross-section, being formed by stepped diameter cylinder, and arrangements using such a device are disclosed. The device may exert sealing forces and be controlled by admission of fluid pressure which acts on a thin wall member so supported as to be subjected to compressive stress alone.
