CN111946836A - Two-way sealing stop valve - Google Patents

Abstract

The invention discloses a two-way sealing globe valve, which comprises: a sleeve is installed in a valve seat, a main valve disc and a main valve disc nut are installed in the sleeve, and the main valve disc nut is installed on the main valve disc. On the valve flap, there is a cavity between the main valve flap nut and the main valve flap; the first flow hole communicates through the lower part of the cavity; the second flow hole communicates with the outlet after passing through the side wall of the valve flap the bottom of the cavity; the cavity is provided with a pilot valve flap; 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 the columnar depression A disc is rotatably installed; a pilot valve disc nut is installed in the cylindrical recess above the disc; a valve stem passes through the valve seat, and the pilot disc nut is fixed to the disc. The structure of the invention realizes the bidirectional sealing requirement when two different working conditions are switched.

Description

Two-way sealing globe valve

technical field

The invention relates to a valve, in particular to a two-way sealing shut-off valve.

Background technique

The globe valve is a forced sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from under the valve disc, the resistance that the operating force needs to overcome is the friction force 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 valve stem The diameter of the valve should be large, otherwise the failure of the top of the valve stem will occur. In recent years, since the emergence of self-sealing valves, the medium flow direction of the globe valve has been changed from the top of the valve disc into the valve cavity. 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 valve stem's force is small. The diameter can be reduced accordingly. At the same time, under the action of the medium, this form of valve is also tighter.

At present, the design of domestic hard-sealed globe valves has included a variety of caliber specifications, and the hard-sealing requirements of high temperature and high pressure difference have been achieved. However, it cannot meet the large changes in the pressure difference of the existing industry, especially in nuclear-grade valves, such as (0.5~2MPa and 15~20MPa), and it is a special requirement for the action in the opposite direction.

Therefore, the present invention is devoted to providing a valve trim structure capable of realizing two-way high pressure differential sealing of the globe valve, adopting the hard sealing structure of the stop valve with the pressure balance of the B-end sleeve, and using the pressure of the B-end to balance the part of the valve stem to force the valve. When the necessary sealing specific pressure is reached, the valve stem thrust is the smallest; at the same time, when the inlet pressure is zero and the B side maintains high pressure, the self-compression force of the sealing surface can also achieve high sealing requirements. Open the pressure balance hole to balance the pressure difference, reduce the valve stem tension when the valve is opened, reduce the flow resistance, and increase the flow area.

SUMMARY OF THE INVENTION

Above-mentioned purpose of the present invention is achieved through the following technical solutions:

A two-way sealing globe valve, comprising: a sleeve is installed in a valve seat, a main valve disc and a main valve disc nut are installed in the sleeve, and the main valve disc nut is installed on the main valve disc, There is a cavity between the main valve flap nut and the main valve flap; the first flow hole communicates through the lower part of the cavity; the second flow hole passes through the side wall of the valve flap and the outlet communicates with the cavity bottom; a pilot valve flap is arranged in 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 recess, and a rotatable installation in the columnar recess There is a disc; a pilot valve disc nut is installed in the cylindrical recess above the disc; the valve stem passes through the valve seat, and the pilot disc nut is fixed with the disc.

The above-mentioned two-way sealing globe valve, wherein, the sleeve is provided with a first round hole corresponding to the inlet position of the second flow hole; the valve seat has a first channel and a second channel, and the first channel communicates with all the the first circular hole; the second passage communicates with the lower opening of the sleeve.

The above-mentioned two-way sealing globe valve, wherein an annular clamping groove is opened between the upper surface and the outer side of the main valve flap, a sealing ring is installed in the annular clamping groove, and the upper wall of the sealing ring is connected to the outer side. The main valve disc nut is in close contact.

In the above-mentioned two-way sealing globe valve, wherein, a friction-reducing pad is installed on the upper surface of the pilot valve disc.

In the above-mentioned bidirectional sealing globe valve, a plurality of buffer springs are further arranged in the cavity, and the buffer springs are connected between the pilot valve flap and the main valve flap.

The bidirectional sealing globe valve as described above, wherein the sleeve comprises 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 plane; The lower part of the main valve flap is matched with the lower section; the upper part of the main valve flap is matched with the upper section, and the middle part of the main valve flap has an inclined surface matched with the inclined surface of the connecting part.

In the above-mentioned two-way sealing globe valve, wherein the first sealing surface is formed by abutting between the lower end surface of the sleeve and the sleeve.

In the above-mentioned two-way sealing globe valve, wherein the sleeve is further provided with a second round hole, and the sleeve has a side cavity in communication with the second round hole.

To sum up, 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 disc and the main valve disc nut are installed in the sleeve, and the two are installed. A pilot valve disc is set in the formed cavity, so that in the process of rotating the screw, the pilot valve disc will rise first, the second flow hole will be opened, the fluid will enter the channel, and the pressure difference between the first channel and the second channel in the valve body cavity will be balanced and reduced. The opening force of the valve stem. The structure of the invention ensures the minimum thrust of the two-way sealing valve stem in the closed position; at the same time, the opening of the pilot valve flap is increased to solve the minimum pulling force of the valve stem when the valve is opened; and the bidirectional sealing requirement when switching between two different working conditions is realized.

Description of drawings

Fig. 1 is the structural representation of the two-way sealing globe valve of the present invention;

Fig. 2 is a partial enlarged view of part C of the two-way sealing globe valve of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the present invention is further described:

Fig. 1 is a schematic diagram of the structure of the two-way sealing globe valve of the present invention, Fig. 2 is a partial enlarged view of the C part of the two-way sealing globe valve of the present invention, please refer to Fig. 1, Fig. 2, a two-way sealing globe valve, which includes: a valve seat 3. A sleeve 1 is installed in the sleeve 1, and the main valve disc 2 and the main valve disc nut 8 are installed in the sleeve 1. The main valve disc nut 8 is installed on the main valve disc 2, and the main valve disc nut 8 and the main valve disc 2 are between There is a cavity; the first flow hole 4 communicates through the lower part of the cavity; the second flow hole 5 passes through the side wall of the valve flap and the outlet communicates with the bottom of the cavity; the cavity is provided with a pilot valve flap 6; the pilot valve flap 6 is arranged at Above the outlet of the second flow hole 5; the upper surface of the pilot valve disc 6 has a cylindrical recess, and a disc is rotatably installed in the cylindrical recess; the pilot valve disc nut 11 is installed in the cylindrical recess above the disc; the valve stem 10 passes through The valve seat 3 and the pilot valve disc nut 11 are fixed to the disc. During the opening process, the valve stem 10 rises during the rotation process, driving the disc to rise, the disc drives the pilot valve disc 6 to rise, the lower part of the pilot valve disc 6 is released from contact with the outlet of the second flow hole 5, the valve stem 10 continues to rotate, and the pilot valve The flap 6 rises, and the pilot flap nut 11 abuts against the main flap nut 8 above, driving the main flap 2 to rise. In the present invention, by setting the pilot valve flap 6, that is, first the fluid enters the middle cavity (the middle cavity above the main valve flap nut 8) and the fluid pressure tends to balance, and then the main valve flap 2 is fully opened, so that the valve is easy to open and reduces the valve opening rate. 10 tension of the valve stem.

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

Specifically, the B end in FIG. 1 is in the first flow channel, and the A end is in the second flow channel. The upper part of the main valve disc nut 8 and the sleeve 1 is the middle cavity. The first flow hole 4 communicates with the B end and the middle cavity, so as to realize the pressure balance between the middle cavity and the B end

Further, an annular clamping groove is formed between the upper surface and the outer side of the main valve disc 2 , a sealing ring 9 is installed in the annular clamping groove, and the upper wall of the sealing ring 9 is in close contact with the main valve disc nut 8 . The sealing ring 9 can be made of the following materials, such as: O-ring, packing, etc.

Further, a friction reducing pad 7 is installed on the upper surface of the pilot valve disc 6 . The anti-friction pad 7 is arranged at the bottom of the cylindrical recess, so that the friction between the disc and the pilot valve disc 6 can be reduced. The anti-friction pad 7 may be annular, and the outlet of the second flow hole 5 may be set at a position where the anti-friction pad 7 is hollow. The two do not affect each other.

Further, a plurality of buffer springs 12 are also arranged in the cavity, and the buffer springs 12 are connected between the pilot valve disc 6 and the main valve disc 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.

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 is matched with the lower section; the upper part of the main valve flap 2 is matched with the upper section. The connecting part between the upper section and the lower section has an inclined surface, the middle of the main valve disc 2 has a matching inclined surface, and the two inclined surfaces are arranged oppositely. When the stop valve of the present invention is closed, the inclined surface of the sleeve 1 and the inclined surface of the main valve disc 2 are in close contact The second sealing surface 22 is formed.

Further, when the shut-off valve of the present invention is closed, the lower end surface of the sleeve 1 and the sleeve 1 abut to form the first sealing surface 21 .

In the present invention, by setting the valve seat 3 and setting 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 entire globe valve can be extended by replacing the valve seat 3 service life.

The first sealing surface 21 and the second sealing surface 22 of the present invention form a combined seal, so that the sealing reliability is higher.

By arranging the valve seat 3 and setting 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 valve seat 3 can be replaced to extend the entire shut-off valve. service life.

Further, the sleeve 1 is also provided with a second round hole, and the sleeve 1 has a side cavity in communication with the second round hole.

In the specific implementation process of the present invention, the specific operation mode of the present invention can be:

When the shut-off valve is closed, the fluid at the B end reaches the middle cavity of the valve body through the first flow hole 4 on the main valve disc 2, so that the valve stem 10 is stressed by the pressure balance part, so that the valve reaches the necessary sealing pressure. The thrust is the smallest; at the same time, when the pressure at the A end is zero and the B end maintains a high pressure, the self-compression force of the sealing surface can also achieve high sealing requirements. When the valve needs to be opened, the pilot valve disc nut 11 is driven by the valve stem 10, and the pilot valve disc 6 and the pilot valve disc nut 11 are threadedly connected, so that the pilot valve disc 6 is separated from the main valve disc 2, and the valve on the main valve disc 2 is opened. The second flow hole 5, at this time, the fluid enters the valve cavity through the second flow hole 5, and the pressure difference at the inlet B end of the valve is discharged and balanced. At this time, the valve stem 10 is lifted again, and the pilot valve disc nut 11 drives the main valve disc. The nut 8 and the main valve flap 2 go up together, so that the main valve flap 2 is fully opened. In this embodiment, by setting the pilot valve flap 6, that is, the fluid pressure in the middle cavity is first balanced, and then the main valve flap 2 is fully opened. , so as to make the valve open easily and reduce the valve stem tension for valve opening.

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

Claims (8)

1. A bi-directional seal shut-off valve, comprising: a sleeve is arranged in the valve seat, a main valve flap and a main valve flap nut are arranged in the sleeve, the main valve flap nut is arranged on the main valve flap, and a cavity is formed between the main valve flap nut and the main valve flap; a first flow through hole communicates through the lower portion of the cavity; the second flow through hole penetrates through the side wall of the valve clack, and the outlet is communicated with the bottom of the cavity; a pilot valve clack is arranged in the cavity; the pilot valve clack is arranged above the outlet of the second through hole; the upper surface of the pilot valve clack is provided with a columnar recess, and a disc is rotatably arranged in the columnar recess; a pilot valve clack nut is arranged in the columnar recess above the disc; the valve rod penetrates through the valve seat, the pilot valve clack nut and is fixed with the disc.

2. The bidirectional sealing stop valve of claim 1, wherein the sleeve is provided with a first round hole at a position corresponding to the inlet of the second through-flow hole; the valve seat is provided with a first channel and a second channel, and the first channel is communicated with the first round hole; the second channel is communicated with the lower opening of the sleeve.

3. The bidirectional sealing stop valve of claim 1, wherein an annular groove is formed between the upper surface and the outer side edge of the main valve flap, a sealing ring is installed in the annular groove, and the upper wall of the sealing ring is tightly attached to the main valve flap nut.

4. The bi-directional sealing shut-off valve of claim 1, wherein an anti-friction pad is mounted on an upper surface of the pilot flap.

5. The bi-directional sealing stop valve of claim 1, further comprising a plurality of cushioning springs disposed within the cavity, the cushioning springs being connected between the pilot flap and the main valve flap.

6. The bi-directional sealing shut-off valve of claim 1, wherein the sleeve comprises an upper section, a lower section, the lower section being smaller in diameter than the upper section, a connection between the upper section and the lower section having a bevel; the lower part of the main valve flap is matched with the lower section; the upper part of the main valve flap is matched with the upper part section, and the middle part of the main valve flap is provided with an inclined plane matched with the inclined plane of the connecting part.

7. The bi-directional seal stop valve of claim 1, wherein a first sealing surface is formed between the lower end surface of the sleeve and the sleeve.

8. The bidirectional sealing stop valve of claim 1, wherein the sleeve further defines a second circular aperture, and the sleeve has a side cavity therein communicating with the second circular aperture.

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