Double-blocking and double-isolating type combined needle valve

Abstract

An inlet end and an outlet end are arranged on the two sides of a valve body of the double-blocking double-isolation type combined needle valve, and a plurality of crossed overflowing cavities are formed in the portion, between the inlet end and the outlet end, of the valve body and are communicated with one another. The upper part and the lower part of the valve body are provided with a first interface, a second interface, a third interface and a fourth interface which are respectively and correspondingly provided with a first needle valve, a second needle valve, a third needle valve and a screw plug; the first needle valve and the second needle valve control opening and closing of the overflowing cavity to form double blocking and double isolation of media. The third needle valve is simultaneously communicated with the pipeline at the outlet end and the discharge overflowing cavity; and a screw plug is arranged at the outlet of the discharge overflowing cavity. The three valves are combined and integrated into a whole, multiple functions are achieved, the effect of reducing leakage points is achieved, and the manufacturing cost is also saved.

Description

Technical Field

[0001] The invention relates to the technical field of valve manufacturing, and in particular to a double-blocking and double-isolating combined needle valve. Background Art

[0002] The consumption of traditional energy sources such as chemical fuels and the increasingly severe environmental pressure have led to an increasing demand for new clean energy. Hydrogen energy and hydrogen fuel cells are increasingly valued by countries around the world due to their good environmental performance, high energy conversion efficiency and certain economic efficiency. Therefore, hydrogen refueling stations have become a necessary way to develop the hydrogen energy industry. At present, the more mature technologies are 35MPa and 70MPa hydrogen refueling stations. In order to promote the localization of equipment, the development of ultra-high pressure valves is also a key link. In general, in order to achieve its multiple functions, multiple valves are installed separately. In a high-pressure working environment, there is a potential risk of leakage, which causes safety hazards, and increases costs and installation troubles. Summary of the invention

[0003] The present invention provides a double-blocking and double-isolating combined needle valve, which realizes the functions of double blocking and double isolation and avoids the problem of multiple leakage points and installation trouble caused by independent installation of a single valve.

[0004] The technical solution adopted by the present invention is: A double-blocking and double-isolation combined needle valve, comprising a valve body, wherein an inlet end and an outlet end are arranged on both sides of the valve body, and a plurality of cross-flow chambers are arranged on the valve body between the inlet end and the outlet end and are interconnected; a first interface and a second interface are arranged on the upper part of the valve body, and a third interface and a fourth interface are arranged on the lower part of the valve body, and a first needle valve, a second needle valve, a third needle valve and a screw plug are installed correspondingly respectively; the first needle valve and the second needle valve control the opening and closing of the flow chamber to form a double-blocking and double-isolating medium; the medium flows in from the inlet end and flows along the first flow chamber, and when the first needle valve is closed, the medium is blocked from reaching the second flow chamber, and when the first needle valve leaks, the medium reaches the second flow chamber, and the second needle valve is closed to block the medium from reaching the third flow chamber, thereby preventing the medium from flowing out from the outlet end, thereby forming a double-blocking function; The second needle valve and the first needle valve are closed at the same time, isolating the medium in the second flow chamber from flowing back to the inlet end, isolating the medium in the second flow chamber from flowing out to the outlet end, forming a double isolation function; the third needle valve is connected to the pipeline at the outlet end and the discharge flow chamber at the same time, and a screw plug is installed at the outlet of the discharge flow chamber.

[0005] The valve covers and valve bodies of the first needle valve, the second needle valve and the third needle valve are connected through fine thread and then contact each other through conical surfaces.

[0006] A flexible graphite-wrapped metal wire gasket is arranged between the valve cover and the valve body.

[0007] A V-shaped packing seal is arranged between the valve cover and the valve stem. The V-shaped packing is divided into an upper packing, a middle packing and a lower packing. The packing gland presses the V-shaped packing tightly.

[0008] A disc spring is arranged between the packing gland and the pressure cap, and the pressure cap is threadedly connected with the valve cover.

[0009] The valve cover and the screw plug are both provided with anti-rotation screws.

[0010] The present invention utilizes three needle valves and a discharge screw plug to form an integrated integrated valve structure. The two needle valves provide double-layer blocking and double-layer isolation functions in the forward and reverse directions, avoiding the independent installation of a single valve, resulting in multiple leakage points and installation troubles, and also saving manufacturing costs. In addition, a needle valve is arranged at the upstream end to discharge pipeline pressure, reduce leakage, avoid direct discharge, and facilitate pipeline system maintenance and shutdown. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the structure of the valve body assembly of the present invention; Figure 2 This is a schematic diagram of the valve cover connection structure of the present invention; Figure 3 This is a schematic diagram of the packing installation structure of the present invention; Figure 4 It is a schematic diagram of the valve cover anti-rotation structure of the present invention. DETAILED DESCRIPTION

[0012] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] Reference Figure 1 , a double-blocking and double-isolation combined needle valve, comprising a valve body, wherein the valve body 1 is provided with an inlet end 1-1 and an outlet end 2-2 on both sides, and a plurality of cross-flow chambers are provided on the valve body between the inlet end 1-1 and the outlet end 2-2 and are interconnected; a first interface and a second interface are provided on the upper part of the valve body 1, and a third interface and a fourth interface are provided on the lower part of the valve body 1, and a first needle valve 2, a second needle valve 3, a third needle valve 4 and a screw plug 5 are installed respectively; the first needle valve 2 and the second needle valve 3 control the opening and closing of the flow chamber to form a double-blocking and double-isolating medium; the medium flows in from the inlet end 1-1 and flows along the first flow chamber a. When the first needle valve 2 is closed, the medium is blocked from reaching the second flow chamber b. When the first needle valve 2 leaks, the medium reaches the second flow chamber b, and the second needle valve 3 is closed to block the medium from reaching the third flow chamber c, thereby preventing the medium from flowing out from the outlet end 2-2, thereby forming a double-blocking function; The second needle valve 3 and the first needle valve 2 are closed at the same time, isolating the medium in the second flow chamber b from flowing back to the inlet end 1-1, isolating the medium in the second flow chamber b from flowing out to the outlet end 2-2, forming a double isolation function; the third needle valve 4 is connected to the pipeline at the outlet end and the discharge flow chamber at the same time, and a screw plug 5 is installed at the outlet of the discharge flow chamber.

[0014] Reference Figure 1 The valve cover 6 of the first needle valve 2, the second needle valve 3, and the third needle valve 4 are connected to the valve body 1 through fine thread connection and contact each other through the conical surface 13. The valve cover 6 thread is rotated to provide pre-tightening force, and the valve cover 6 and the valve body 1 contact each other through the conical surface 13, which plays a mandatory metal seal. The sealing surface angle of the conical surface 13 is 60°, and the contacting sealing surfaces are welded with hard alloy to form the first seal between the valve cover 6 and the valve body 1.

[0015] Reference Figure 2 A flexible graphite wound gasket 7 is provided between the valve cover 6 and the valve body 1. The valve cover 6 is rotated to compress the flexible graphite wound gasket 7 to form a second seal between the valve cover 6 and the valve body 1.

[0016] Reference Figure 3 A V-shaped packing seal is arranged between the valve cover 6 and the valve stem 7. The V-shaped packing is divided into an upper packing 8-1, a middle packing 8-2, and a lower packing 8-3. A packing gland 9 presses the V-shaped packing. A disc spring 10 is arranged between the packing gland 9 and a pressure cap 11. The pressure cap 11 is threadedly connected to the valve cover 6. The pressure cap 11 is rotated, and the pressure cap 11 presses the disc spring 10. The disc spring 10 provides a pre-tightening force to the packing gland 9. The packing gland 9 presses the V-shaped packing 8 to ensure the sealing of the valve stem 7.

[0017] Reference Figure 4 The valve cover 6 and the screw plug 5 are both provided with anti-rotation screws 12. The valve cover 6 and the screw plug 5 are in the shape of a regular hexagon. The valve cover 6 and the screw plug 5 are rotated into place, and the screws 12 are installed to fix the valve cover 6 and the screw plug 5 to prevent the valve cover 6 and the screw plug 5 from rotating, which may cause the seal between the valve cover 6 and the screw plug 5 and the metal cone surface 13 of the valve body 1 to loosen and cause leakage.

Claims

1. A double-blocking and double-isolating combined needle valve, comprising a valve body, characterized in that: The valve body (1) is provided with an inlet end (1-1) and an outlet end (2-2) on both sides, and a plurality of cross-flow chambers are provided on the valve body between the inlet end (1-1) and the outlet end (2-2) and are interconnected; the upper part of the valve body (1) is provided with a first interface and a second interface, and the lower part of the valve body (1) is provided with a third interface and a fourth interface, and the first needle valve (2), the second needle valve (3), the third needle valve (4) and the screw plug (5) are installed correspondingly; the first needle valve (2) and the second needle valve (3) control the opening and closing of the flow chamber to form a double blocking and double isolation of the medium; the medium flows in from the inlet end (1-1) and flows along the first flow chamber (a); when the first needle valve (2) is closed, the medium is blocked from reaching the second flow chamber (b); when the first needle valve (2) leaks and the medium reaches the second flow chamber (b), the second needle valve (3) is closed, the medium is blocked from reaching the third flow chamber (c), and the medium is prevented from flowing out from the outlet end (2-2), thereby forming a double blocking function; the second needle valve (3) The third needle valve (4) is closed simultaneously with the first needle valve (2), isolating the medium in the second flow chamber (b) from flowing back to the inlet end (1-1), and isolating the medium in the second flow chamber (b) from flowing out to the outlet end (2-2), thereby forming a double isolation function; the third needle valve (4) is simultaneously connected to the pipeline at the outlet end and the discharge flow chamber, and a screw plug (5) is installed at the outlet of the discharge flow chamber.

2. A double-blocking and double-isolating combined needle valve according to claim 1, characterized in that: The valve covers (6) of the first needle valve (2), the second needle valve (3) and the third needle valve (4) are connected to the valve body (1) via fine thread and then contact each other via the conical surface (13).

3. A double-blocking and double-isolating combined needle valve according to claim 2, characterized in that: A flexible graphite metal wire wound gasket (7) is provided between the valve cover (6) and the valve body (1).

4. A double-blocking and double-isolating combined needle valve according to claim 3, characterized in that: A V-shaped packing seal is arranged between the valve cover (6) and the valve stem (7), the V-shaped packing is divided into an upper packing (8-1), a middle packing (8-2) and a lower packing (8-3), and a packing gland (9) compresses the V-shaped packing.

5. A double-blocking and double-isolating combined needle valve according to claim 4, characterized in that: A disc spring (10) is provided between the packing gland (9) and the pressure cap (11), and the pressure cap (11) is threadedly connected to the valve cover (6).

6. A double-blocking and double-isolating combined needle valve according to any one of claims 1 to 5, characterized in that: The valve cover (6) and the screw plug (5) are both provided with anti-rotation screws (12).

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