Two-way sealed globe valve

Abstract

The present invention discloses a two-way sealing stop valve, which includes: a sleeve is installed inside a valve seat, a main valve flap and a main valve flap nut are installed inside the sleeve, the main valve flap nut is installed on the main valve flap, and there is a cavity between the main valve flap nut and the main valve flap; a first flow hole penetrates through the lower part of the cavity; a second flow hole penetrates through the side wall of the valve flap and the outlet communicates with the bottom of the cavity; a pilot valve flap is arranged inside the cavity; the pilot valve flap is arranged above the outlet of the second flow hole; the upper surface of the pilot valve flap has a columnar depression, and a disc is rotatably installed inside the columnar depression; a pilot valve flap nut is installed inside the columnar depression above the disc; a valve rod passes through the valve seat, the pilot valve flap nut and is fixed to the disc. The structure of the present invention realizes the two-way sealing requirements when switching between two different working conditions.

Description

Technical Field

[0001] The present invention relates to a valve, and more particularly to a two-way sealing globe valve. Background Art

[0002] A globe valve belongs to a forced-sealing valve. Therefore, when the valve is closed, pressure must be applied to the valve flap to force the sealing surface not to leak. When the medium enters the valve from below the valve flap, the resistance that the operating force needs to overcome is the friction between the valve stem and the packing and the thrust generated by the pressure of the medium. The force to close the valve is greater than the force to open the valve, so the diameter of the valve stem needs to be large, otherwise the valve stem will be bent. In recent years, since the appearance of self-sealing valves, the flow direction of the medium in the globe valve has changed to enter the valve cavity from above the valve flap. At this time, under the action of the medium pressure, the force to close the valve is small, while the force to open the valve is large, and the diameter of the valve stem can be correspondingly reduced. At the same time, under the action of the medium, this type of valve is also relatively tight.

[0003] At present, the design of domestic hard-sealing globe valves already includes various calibers and has achieved the hard-sealing requirements for high temperature and high pressure difference. However, it cannot meet the special requirements of the existing industry, especially in nuclear-grade valves, where the pressure difference borne by the seal changes greatly, such as (0.5 - 2 MPa and 15 - 20 MPa), and the acting directions are opposite.

[0004] Therefore, the present invention is committed to providing a valve internal part structure for a two-way high-pressure difference sealing globe valve, adopting a B-end sleeve pressure-balanced hard-sealing structure for the globe valve. By using the pressure-balanced part at the B-end to balance the force on the valve stem, the thrust of the valve stem is minimized when the valve reaches the required sealing specific pressure. At the same time, when the inlet pressure is zero and the B-end remains at high pressure, the self-compacting force of the sealing surface can also achieve high sealing requirements. Since the force to open the valve flap is relatively large, the pilot-operated opening pressure balance hole is reasonably utilized to release and balance the pressure difference, reduce the pulling force of the valve stem when opening the valve, reduce the flow resistance, and increase the flow area. Summary of the Invention

[0005] The above object of the present invention is achieved by the following technical solutions:

[0006] A two-way sealing globe valve, comprising: a sleeve is installed inside the valve seat, a main valve flap and a main valve flap nut are installed inside the sleeve, the main valve flap nut is installed on the main valve flap, and there is a cavity between the main valve flap nut and the main valve flap; a first flow hole penetrates through the lower part of the cavity; a second flow hole penetrates through the side wall of the valve flap and its outlet communicates with the bottom of the cavity; a pilot valve flap is arranged inside the cavity; the pilot valve flap is arranged above the outlet of the second flow hole; the upper surface of the pilot valve flap has a columnar depression, and a disc is rotatably installed inside the columnar depression; a pilot valve flap nut is installed inside the columnar depression above the disc; the valve stem passes through the valve seat, the pilot valve flap nut and is fixed to the disc.

[0007] The two-way sealed globe valve as described above, wherein a first round hole is provided at the inlet position of the sleeve corresponding to the second flow hole; the valve seat has a first channel and a second channel, and the first channel communicates with the first round hole; the second channel communicates with the lower opening of the sleeve.

[0008] The two-way sealed globe valve as described above, wherein an annular groove is provided between the upper surface and the outer side of the main valve flap, a sealing ring is installed in the annular groove, and the upper wall of the sealing ring is in close contact with the main valve flap nut.

[0009] The two-way sealed globe valve as described above, wherein an anti-friction pad is installed on the upper surface of the pilot valve flap.

[0010] The two-way sealed globe valve as described above, wherein a plurality of buffer springs are further provided in the cavity, and the buffer springs are connected between the pilot valve flap and the main valve flap.

[0011] The two-way sealed globe valve as described above, wherein the sleeve includes an upper section and a lower section, the diameter of the lower section is smaller than that of the upper section, and the connecting portion between the upper section and the lower section has an inclined surface; the lower part of the main valve flap matches the lower section; the upper part of the main valve flap matches the upper section, and the middle part of the main valve flap has an inclined surface matching the inclined surface of the connecting portion.

[0012] The two-way sealed globe valve as described above, wherein the lower end surface of the sleeve abuts against the sleeve to form a first sealing surface.

[0013] The two-way sealed globe valve as described above, wherein the sleeve is further provided with a second round hole, and a side cavity communicating with the second round hole is provided in the sleeve.

[0014] In summary, due to the adoption of the above technical solutions, a sleeve is installed in the valve seat of the present invention, the valve seat has a first channel and a second channel, the main valve flap and the main valve flap nut are installed in the sleeve, and a pilot valve flap is arranged in the cavity formed by the two, so that during the process of rotating the screw, the pilot valve flap will rise first, the second flow hole will be opened, the fluid will enter the channel, balance the pressure difference between the first channel and the second channel in the valve body cavity, and reduce the opening force of the valve stem. The structure of the present invention ensures that the two-way sealing valve stem thrust is the smallest in the closed position; at the same time, the pilot valve flap opening is increased to solve the problem that the valve stem pulling force is the smallest when the valve is opened; the two-way sealing requirements during the switching of two different working conditions are realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the two-way sealed globe valve of the present invention;

[0016] Figure 2It is a partial enlarged view of part C of the two-way sealing globe valve of the present invention. Detailed implementation manners

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0018] Figure 1 It is a schematic structural view of the two-way sealing globe valve of the present invention. Figure 2 It is a partial enlarged view of part C of the two-way sealing globe valve of the present invention. Please refer to Figure 1 、 Figure 2 A two-way sealing globe valve, which includes: a sleeve 1 is installed in a valve seat 3, a main valve flap 2 and a main valve flap nut 8 are installed in the sleeve 1, the main valve flap nut 8 is installed on the main valve flap 2, and there is a cavity between the main valve flap nut 8 and the main valve flap 2; a first flow hole 4 communicates through the lower part of the cavity; a second flow hole 5 passes through the side wall of the valve flap and its outlet communicates with the bottom of the cavity; a pilot valve flap 6 is arranged in the cavity; the pilot valve flap 6 is arranged above the outlet of the second flow hole 5; the upper surface of the pilot valve flap 6 has a columnar depression, and a disc is rotatably installed in the columnar depression; a pilot valve flap nut 11 is installed in the columnar depression above the disc; a valve stem 10 passes through the valve seat 3, the pilot valve flap nut 11 and is fixed to the disc. During the opening process, when the valve stem 10 rotates and rises, it drives the disc to rise, the disc drives the pilot valve flap 6 to rise, the lower part of the pilot valve flap 6 is disengaged from the outlet of the second flow hole 5, the valve stem 10 continues to rotate, the pilot valve flap 6 rises, and the pilot valve flap nut 11 abuts against the upper main valve flap nut 8, driving the main valve flap 2 to rise. By setting the pilot valve flap 6 in the present invention, the fluid first enters the middle cavity (the upper part of the main valve flap nut 8 is the middle cavity) and the fluid pressure tends to be balanced, and then the main valve flap 2 is fully opened, so that the valve is easy to open and the pulling force of the valve stem 10 for opening the valve is reduced.

[0019] Further, the sleeve 1 is provided with a first round hole at the position corresponding to the inlet of the second flow hole 5; the valve seat 3 has a first channel (B end) and a second channel (A end), the first channel communicates with the first round hole; the second channel communicates with the lower opening of the sleeve 1.

[0020] Specifically, Figure 1 The B end in is in the first flow channel, and the A end is in the second flow channel. The middle cavity is between the upper part of the main valve flap nut 8 and the sleeve 1. The first flow hole 4 communicates the B end with the middle cavity to achieve pressure balance between the middle cavity and the B end.

[0021] Further, a ring-shaped slot is provided between the upper surface and the outer side of the main valve flap 2, and a sealing ring 9 is installed in the ring-shaped slot, and the upper wall of the sealing ring 9 is in close contact with the main valve flap nut 8. The sealing ring 9 can adopt the following materials, for example: O-ring, packing, etc.

[0022] Further, an anti-friction pad 7 is mounted on the upper surface of the pilot valve flap 6. The anti-friction pad 7 is arranged at the bottom of the columnar depression, so that the friction between the disc and the pilot valve flap 6 can be reduced. The anti-friction pad 7 can be annular, and the outlet of the second flow hole 5 can be arranged at the hollow position of the anti-friction pad 7. There is no mutual influence between the two.

[0023] Further, a plurality of buffer springs 12 are also arranged in the cavity. The buffer springs 12 are connected between the pilot valve flap 6 and the main valve flap 2. In the present invention, a buffer spring 12 is arranged between the main valve flap 2 and the pilot valve flap 6, which plays a buffering role when the pilot valve flap 6 is closed.

[0024] Further, the sleeve 1 includes an upper section and a lower section. The diameter of the lower section is smaller than that of the upper section; the lower part of the main valve flap 2 matches the lower section; the upper part of the main valve flap 2 matches the upper section. The connecting part between the upper section and the lower section has an inclined surface, and the middle part of the main valve flap 2 is correspondingly provided with an inclined surface. The two inclined surfaces are arranged oppositely. When the stop valve of the present invention is closed, the inclined surface of the sleeve 1 is closely attached to the inclined surface of the main valve flap 2 to form a second sealing surface 22.

[0025] Further, when the stop valve of the present invention is closed, the lower end surface of the sleeve 1 abuts against the sleeve 1 to form a first sealing surface 21.

[0026] In the present invention, by providing the valve seat 3 and arranging the first sealing surface on the valve seat 3, when the first sealing surface fails due to long-term erosion or cavitation of the fluid in the valve, the service life of the entire stop valve can be extended by replacing the valve seat 3.

[0027] The first sealing surface 21 and the second sealing surface 22 of the present invention form a combined seal, making the sealing reliability higher.

[0028] By providing the valve seat 3 and arranging the first sealing surface 21 on the valve seat 3, when the first sealing surface 21 fails due to long-term erosion or cavitation of the fluid in the valve, the service life of the entire stop valve can be extended by replacing the valve seat 3.

[0029] Further, the sleeve 1 is also provided with a second round hole, and a side cavity communicating with the second round hole is provided in the sleeve 1.

[0030] In the specific implementation process of the present invention, the specific operation method of the present invention can be:

[0031] When the globe valve is closed, the fluid at the B end passes through the first flow hole 4 on the main valve flap 2 to reach the middle cavity of the valve body, thereby using the pressure balance part to make the valve stem 10 bear force, so that the thrust of the valve stem 10 is minimized when the valve reaches the required sealing specific pressure; at the same time, when the pressure at the A end is zero and the B end maintains a high pressure, the self-tightening force of the sealing surface can also achieve high sealing requirements. When the valve needs to be opened, the pilot valve flap nut 11 is driven by the valve stem 10, and the pilot valve flap 6 is threadedly connected to the pilot valve flap nut 11, so that the pilot valve flap 6 is separated from the main valve flap 2, and the second flow hole 5 on the main valve flap 2 is opened. At this time, the fluid enters the middle cavity of the valve through the second flow hole 5, and the pressure difference at the B end of the valve is discharged and balanced. At this time, when the valve stem 10 is lifted again, the pilot valve flap nut 11 drives the main valve flap nut 8 and the main valve flap 2 to move upward together, so that the main valve flap 2 is fully opened. In this embodiment, by setting the pilot valve flap 6, that is, first making the fluid pressure in the middle cavity tend to be balanced, and then fully opening the main valve flap 2, the valve is easy to open and the valve stem pulling force for opening the valve is reduced.

[0032] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative labor or through software programming. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A two-way sealed globe valve, characterized in that, a sleeve is installed inside the valve seat, a main valve flap and a main valve flap nut are installed inside the sleeve, the main valve flap nut is installed on the main valve flap, and there is a cavity between the main valve flap nut and the main valve flap; a first flow hole penetrates through the lower part of the cavity; a second flow hole penetrates through the side wall of the main valve flap and the outlet communicates with the bottom of the cavity; a pilot valve flap is arranged inside the cavity; the pilot valve flap is arranged above the outlet of the second flow hole; a columnar depression is formed on the upper surface of the pilot valve flap, and a disc is rotatably installed inside the columnar depression; a pilot valve flap nut is installed inside the columnar depression above the disc; the valve stem passes through the valve seat, the pilot valve flap nut and is fixed to the disc; a first round hole is opened at the inlet position of the sleeve corresponding to the second flow hole; the valve seat has a first channel and a second channel, and the first channel communicates with the first round hole; the second channel communicates with the lower opening of the sleeve; the sleeve includes an upper section and a lower section, the diameter of the lower section is smaller than that of the upper section, and the connecting part between the upper section and the lower section has an inclined surface; the lower part of the main valve flap matches the lower section; the upper part of the main valve flap matches the upper section, and the middle part of the main valve flap has an inclined surface matching the inclined surface of the connecting part; a first sealing surface is formed by the abutting between the lower end surface of the sleeve and the valve seat.

2. The two-way sealed globe valve according to claim 1, characterized in that, a ring-shaped clamping groove is formed between the upper surface of the main valve flap and the outer side edge of the sleeve, a sealing ring is installed inside the ring-shaped clamping groove, and the upper wall of the sealing ring is in close contact with the main valve flap nut.

3. The two-way sealed globe valve according to claim 1, characterized in that, an anti-friction pad is installed on the upper surface of the pilot valve flap.

4. The two-way sealed globe valve according to claim 1, characterized in that, a plurality of buffer springs are further arranged inside the cavity, and the buffer springs are connected between the pilot valve flap and the main valve flap.

5. The two-way sealed globe valve according to claim 1, characterized in that, the sleeve is further provided with a second round hole, and a side cavity communicating with the second round hole is arranged inside the sleeve.

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