A sleeve for a valve assembly has an annular body with an inside surface extending from a first axial sleeve-end to a second axial sleeve-end. The inside surface has a first cylindrical section and a second cylindrical section with a conical interior seating surface extending therebetween. A groove extends circumferentially around and radially outward in the first cylindrical section and axially away from the conical interior seating surface towards the first axial sleeve-end. The sleeve includes one or more first ports that extend radially through the first cylindrical section and spaced apart from the groove. The one or more first ports are spaced apart from the groove by a lip formed by the first cylindrical section. The lip extends continuously and entirely circumferentially around the first cylindrical surface and extends a predetermined axial distance between the groove and the one or more first ports.

A sleeve for a valve assembly has an inside surface having an interior area and a first cylindrical section extending from a first axial end and a second cylindrical section located between the first cylindrical section and second axial end. A conical interior seating surface extends between the first and second cylindrical sections. The conical interior seating surface is metallic. The sleeve includes a groove that extends circumferentially around and radially outward in the first cylindrical section. The groove extends axially away from the conical interior seating surface towards the first axial end. The sleeve has one or more ports extending radially through the first cylindrical section proximate the groove and are spaced apart from the groove by a lip formed by the first cylindrical section. The lip extends a predetermined axial distance between the groove and the port. The lip extends around the first cylindrical section and radially inward.

A sleeve for a valve assembly has an inside surface having an interior area and a first cylindrical section extending from a first axial end and a second cylindrical section located between the first cylindrical section and second axial end. A conical interior seating surface extends between the first and second cylindrical sections. The conical interior seating surface is metallic. The sleeve includes a groove that extends circumferentially around and radially outward in the first cylindrical section. The groove extends axially away from the conical interior seating surface towards the first axial end. The sleeve has one or more ports extending radially through the first cylindrical section proximate the groove and are spaced apart from the groove by a lip formed by the first cylindrical section. The lip extends a predetermined axial distance between the groove and the port. The lip extends around the first cylindrical section and radially inward.

Provided is a tandem cone valve capable of avoiding or reducing resistance on a valve switch caused by fluid pressure in a pipeline in the opening or closing stage. The cone valve includes valve rods, valve cores and a valve body. The valve cores include a first valve core and a second valve core. The first valve core and the second valve core are coaxially arranged in a valve core cavity. The outer walls of the valve cores are in the shape of cones; the first valve core and the second valve core are stacked one on the other, the first valve core is provided with a first valve core first flow hole and a first valve core second flow hole which penetrate through the inner wall and the outer wall of the first valve core, and the valve core cavity is provided with a valve core cavity flow hole corresponding to the first valve core first flow hole and the first valve core second flow hole. The cone valve is provided with the second valve core stacked coaxially on the base of the first valve core, and the second valve rod driving the second valve core to rotate is arranged in the first valve rod in a sleeved manner, thus the valve is simple and compact in structure; and the two levels of valve cores can each rotate to open/close the valve level by level, thus reducing momentary resistance when opening and closing a large cone valve.

Provided is a tandem cone valve capable of avoiding or reducing resistance on a valve switch caused by fluid pressure in a pipeline in the opening or closing stage. The cone valve includes valve rods, valve cores and a valve body. The valve cores include a first valve core and a second valve core. The first valve core and the second valve core are coaxially arranged in a valve core cavity. The outer walls of the valve cores are in the shape of cones; the first valve core and the second valve core are stacked one on the other, the first valve core is provided with a first valve core first flow hole and a first valve core second flow hole which penetrate through the inner wall and the outer wall of the first valve core, and the valve core cavity is provided with a valve core cavity flow hole corresponding to the first valve core first flow hole and the first valve core second flow hole. The cone valve is provided with the second valve core stacked coaxially on the base of the first valve core, and the second valve rod driving the second valve core to rotate is arranged in the first valve rod in a sleeved manner, thus the valve is simple and compact in structure; and the two levels of valve cores can each rotate to open/close the valve level by level, thus reducing momentary resistance when opening and closing a large cone valve.