Cage valve assembly

Claim 2

A flow control valve for providing bubble tight shut off comprising: a valve body including an interior passageway for flow of fluid, said body further including a support shoulder in said interior passageway; a hard seat ring resting on said shoulder; a soft seat ring resting on said hard seat ring; a hollow valve cage resting on said hard seat ring and securing said soft seat ring between said hard seat ring and said cage; a valve plug slidably engaged within said cage; and a valve bonnet mounted against said valve body for compressively securing said cage, and seats in a fixed relation to said body; wherein said valve plug is guided by an inside surface of said cage and said valve plug further includes a rim seal assembly comprising: a circular sealing ring resting in a notch at the rim of said plug; a resilient ring disposed between said circular sealing ring and said plug urging said sealing ring away from said plug and against said inside surface of said cage; and a washer resting on said sealing ring to restrain motion of said ring in a vertical direction.

Claim 3

A flow control valve for providing bubble tight shut off comprising: a valve body including an interior passageway for flow of fluid, said body further including a support shoulder in said interior passageway; a hard seat ring resting on said shoulder; a soft seat ring resting on said hard seat ring; a hollow valve cage resting on said hard seat ring and securing said soft seat ring between said hard seat ring and said cage; a valve plug slidably engaged within said cage; and a valve bonnet mounted against said valve body for compressively securing said cage, and seats in a fixed relation to said body; wherein an upper rim of said cage and an upper rim of said body form a coplanar surface parallel to a surface of said bonnet; said valve further including a flat circular gasket disposed between said bonnet surface and said coplanar surface; and a circular spiral wound gasket providing fluid sealing in a radial direction and compressive resistant force in an axial direction positioned between said support shoulder and said hard seat ring urging said hard seat ring upward.

Claim 4

A flow control valve for providing bubble tight shut off comprising: a valve body including an interior passageway for flow of fluid, said body further including a support shoulder in said interior passageway; a hard seat ring resting on said shoulder; a soft seat ring resting on said hard seat ring; a hollow valve cage resting on said hard seat ring and securing said soft seat ring between said hard seat ring and said cage; a valve plug slidably engaged within said cage; and a valve bonnet mounted against said valve body for compressively securing said cage, and seats in a fixed relation to said body; wherein an upper rim of said cage and an upper rim of said body form a coplanar surface parallel to a surface of said bonnet; said valve further including a flat circular gasket disposed between said bonnet surface and said coplanar surface; and a circular spiral wound gasket providing fluid sealing in a radial direction and compressive resistant force in an axial direction positioned between said support shoulder and said hard seat ring urging said hard seat ring upward.

Claim 5

A flow control valve structure comprising a valve body and an interior assembly in said body comprising a valve sleeve cage in nested stack assembly on a valve seat ring to be held thereon by a valve bonnet on said valve body, a valve stem and plug combination mounted for valving operation within said cage, said valve seat ring extending radially inward beyond said cage to terminate at least in part with an inner tapered surface, and a readily removable soft seat ring held between said cage and said valve seat ring, said soft seat ring having a portion extending radially inward beyond said cage and along said seat ring, said plug having a tapered periphery for engagement with said inward extension of said soft seat ring to deform said soft seat extension into a plug seat form approaching a continuation of said seat ring taper, with said seat ring taper provided as a back-up seat for said plug taper, beyond said soft seat.

Claim 6

A flow control valve structure comprising a valve body and an interior assembly in said body comprising a valve sleeve cage in nested stack assembly on a valve seat ring to be held thereon by a valve bonnet on said valve body, a valve stem and plug combination mounted for valving operation within said cage, said valve seat ring extending radially inward beyond said cage to terminate at least in part with an inner tapered surface, and a readily removable soft seat ring held between said cage and said valve seat ring, said soft seat ring having a portion extending radially inward beyond said cage and along said seat ring, said plug having a tapered periphery for engagement with said inward extension of said soft seat ring to deform said soft seat extension into a plug seat form approaching a continuation of said seat ring taper, with said seat ring taper provided as a back-up seat for said plug taper, beyond said soft seat.