US-12618479-B2 - Valve assembly useful for cryogenic applications

US12618479B2US 12618479 B2US12618479 B2US 12618479B2US-12618479-B2

Abstract

A valve assembly includes a cartridge that includes a handle coupled to a stem and journaled in a bonnet coupled to an upper end of the stem, and a cage assembly coupled to a lower end of the stem and the bonnet. The cartridge is insertable through an upper end of a valve body, and the bonnet is securable to the upper end of the valve body by means of bonnet bolts. The cage assembly includes an off-set C-ball, which includes a curved face which is coupled to a rotatable C-frame and which is arranged to seal against a curved seat. Rotation of the stem rotates the off-set C-ball to permit or block flow through the cage assembly.

Inventors

Igor Berkovitz
Yoel Hadar

Assignees

HABONIM INDUSTRIAL VALVES & ACTUATORS LTD.

Dates

Publication Date: 20260505
Application Date: 20240924

Claims (10)

1 . A valve assembly comprising: a cartridge that comprises a handle coupled to a stem and journaled in a bonnet coupled to an upper end of said stem, and a cage assembly coupled to a lower end of said stem and said bonnet; wherein said cartridge is insertable through an upper end of a valve body, and said bonnet is securable to the upper end of said valve body by means of bonnet bolts; and wherein said cage assembly comprises an off-set C-ball, which comprises a curved face which is coupled to a rotatable C-frame and which is arranged to seal against a curved seat which is located in an aperture formed in a cage, and wherein rotation of said stem rotates said off-set C-ball to permit or block flow through said cage assembly, and wherein an outer surface of said cage and an outer surface of said curved seat are conical, and said valve body has a conical portion, wherein a conical shape of said conical portion complements a conical shape of said outer surfaces of said cage and a conical shape of said outer surface of said curved seat, and tightening of said bonnet bolts to secure said bonnet to said valve body creates a preload force that forces said conical outer surface of id cage and said conical outer surface of said seat to forcefully move to a fully position in said conical portion, and said preload force creates a sealing preload and sealing effect between said curved seat and said valve body.
2 . The valve assembly according to claim 1 , wherein a bonnet tube portion extends downwards from said bonnet, and said bonnet tube portion, said cage and said curved seat are coupled to each other with one or more fasters.
3 . The valve assembly according to claim 1 , wherein said valve body comprises an end connection.
4 . The valve assembly according to claim 1 , wherein said rotatable C-frame comprises a lower bearing shaft and an upper bearing shaft which comprises a stem interface member that couples with said stem.
5 . The valve assembly according to claim 1 , wherein said curved seat is received in an aperture formed in a first cage half which is coupled to a second cage half to form said cage.
6 . The valve assembly according to claim 1 , wherein there is an offset between a rotation center of said offset C-ball and a body center of said offset C-ball.
7 . The valve assembly according to claim 1 , wherein said off-set C-ball has an orientation in which it is turned to an “approach-to-close” position, in which a cam effect leaves a gap between said curved face of said C-ball and said curved seat to allow flow through the valve assembly.
8 . The valve assembly according to claim 1 , wherein said off-set C-ball has an orientation in which it is turned to a closed position that shuts off flow through the valve assembly, in which said curved face of said C-ball fully touches and seals against said curved seat.
9 . The valve assembly according to claim 1 , wherein said off-set C-ball has an orientation in which it is turned so that said curved face of said C-ball overlaps said curved seat to create an increased torque sealing effect.
10 . The valve assembly according to claim 1 , wherein said cage comprises an annular rim and said curved seat is wedged between said valve body and said annular rim of said cage.

Description

FIELD OF THE INVENTION The present invention generally relates to ball valves, and particularly to a valve assembly which may include a vacuum-jacketed ball valve, particularly useful in cryogenic applications. BACKGROUND OF THE INVENTION Valves for use with extremely low temperature fluid flow, such as liquefied hydrogen or helium, must minimize the heat conduction and heat transfer from the fluid in order to minimize phase change of the cryogenic liquid, that is, to minimize evaporation of the cryogenic liquid into gas. Vacuum-jacketed ball valves are known for such applications. An example of a prior art vacuum-jacketed ball valve is briefly described here with reference to FIGS. 1A and 1B. This example is brought merely to understand a problem with the prior art, which is discussed shortly afterwards. As seen in FIG. 1B, the valve has an operating handle 1 connected to an elongate stem 2 that rotates a ball 3 to either open or close the valve. As seen in FIG. 1A, the ball is housed inside a valve housing 4 that has a fluid port 5. Valve housing 4 is sealingly and tightly closed by bolts 6 that help seal the ball with respect to the valve housing. In order to be able to operate at cryogenic temperatures, the stem 2 is placed inside a vacuum-maintained jacket (vacuum jacket 7, shown in broken lines) that minimizes heat transfer in order to maintain low temperatures. A problem with such prior art vacuum-jacketed ball valves is difficulty of maintenance or repair. In order to replace or repair the ball or seal or other part near or in the housing, one must dismantle the entire vacuum jacket 7 from the jacketed pipeline 8 to gain access to the bolts 6 so that the bolts can be removed to gain access to the inner parts of the valve housing 4. It is noted that globe valves do exist that have top entry, that is, the bonnet is removed for placing a stem through the vacuum jacket, but they have the disadvantage of low flow coefficient and complicated multiple-turn operation during closing or opening. SUMMARY The present invention seeks to provide a valve assembly that solves the problem of the prior art, as is described hereinbelow. The valve assembly of the present invention has a removable cartridge that includes the stem and ball as one unit that is easily mounted in or removed from a valve body which may be mounted in the outer vacuum jacket, and the vacuum jacket does not need to be removed from the pipeline. The removable cartridge is inserted in the valve body and secured by bonnet bolts at the top of the valve body. The ball that is part of the cartridge sits in a valve seat once the cartridge is installed in the outer vacuum jacket. However, just the placement of the cartridge in the valve body may not provide sufficient sealing between the ball and the valve seat in which the ball sits. The invention solves this problem with a unique sealing arrangement between the ball and the valve seat by means of conical shapes of parts and tightening forces of the bonnet bolts that ensure proper ball-to-seat and seat-to-body sealing contact even in cryogenic temperatures, as is described below. There is provided in accordance with a non-limiting embodiment of the invention a valve assembly including a cartridge that includes a handle coupled to a stem and journaled in a bonnet coupled to an upper end of the stem, and a cage assembly coupled to a lower end of the stem and the bonnet, wherein the cartridge is insertable through an upper end of a valve body, and the bonnet is securable to the upper end of the valve body by means of bonnet bolts, and wherein the cage assembly includes an off-set C-ball, which includes a curved face which is coupled to a rotatable C-frame and which is arranged to seal against a curved seat, and wherein rotation of the stem rotates the off-set C-ball to permit or block flow through the cage assembly. In accordance with a non-limiting embodiment of the invention an outer surface of the cage and an outer surface of the curved seat are conical, and the valve body has a conical portion, wherein a conical shape of the conical portion complements a conical shape of these outer surfaces, and tightening of the bonnet bolts to secure the bonnet to the valve body creates a preload force that forces the conical outer surface of the cage and the conical outer surface of the seat to forcefully move to a fully seated position in the conical portion, and the preload force creates a sealing preload and sealing effect between the cage and the valve body, and between the curved seat and the valve body. In accordance with a non-limiting embodiment of the invention the valve body includes an end connection. In accordance with a non-limiting embodiment of the invention the C-frame includes a lower bearing shaft and an upper bearing shaft which includes a stem interface member that couples with the stem. In accordance with a non-limiting embodiment of the invention the curved seat is received in an aperture fo