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] This utility model relates to the field of valve manufacturing technology, specifically to a combined needle valve with double blocking and double isolation. Background Technology

[0002] The consumption of traditional energy sources such as chemical fuels and the increasingly severe environmental pressures have led to a growing demand for new clean energy sources. Hydrogen energy and hydrogen fuel cells are gaining increasing attention worldwide due to their environmental friendliness, high energy conversion efficiency, and economic viability. Therefore, hydrogen refueling stations have become a necessary pathway for the development of the hydrogen energy industry. Currently, 35MPa and 70MPa hydrogen refueling stations are relatively mature technologies. To promote the localization of equipment, the development of ultra-high-pressure valves is also a crucial step. Typically, to achieve multiple functions, multiple valves are installed individually. However, under high-pressure operating environments, this poses potential leakage risks, creating safety hazards, and increasing costs and installation complexity. Utility Model Content

[0003] This invention provides a dual-blocking and dual-isolation combined needle valve, which achieves dual-blocking and dual-isolation functions, and avoids the problems of multiple leakage points and installation trouble caused by the independent installation of a single valve.

[0004] The technical solution adopted in this utility model is:

[0005] A dual-blocking, dual-isolation combined needle valve includes a valve body with an inlet and an outlet on both sides. Multiple interconnected cross-flow chambers are provided on the valve body between the inlet and outlet. The upper part of the valve body has a first interface and a second interface, while the lower part has a third interface and a fourth interface, corresponding to the mounting of a first needle valve, a second needle valve, a third needle valve, and a screw plug, respectively. The first and second needle valves control the opening and closing of the flow chambers to form a dual-blocking, dual-isolation of the medium. The medium flows in from the inlet and along the first flow chamber. When the first needle valve closes, it blocks the medium from reaching the second flow chamber. When the first needle valve leaks, the medium reaches the second flow chamber, and when the second needle valve closes, it blocks the medium from reaching the third flow chamber, preventing the medium from flowing out from the outlet, thus forming a dual-blocking function. The second needle valve and the first needle valve are closed simultaneously to isolate the medium in the second flow chamber from flowing back to the inlet end and to isolate the medium in the second flow chamber from flowing out to the outlet end, thus forming a double isolation function; the third needle valve is simultaneously connected to the pipe at the outlet end and the discharge flow chamber, and a screw plug is installed at the outlet of the discharge flow chamber.

[0006] The valve covers and valve bodies of the first needle valve, the second needle valve, and the third needle valve are connected by fine thread and then contact each other through conical surfaces.

[0007] A flexible graphite-coated metal wire wound gasket is provided between the valve cover and the valve body.

[0008] The valve cover and valve stem are provided with a V-type packing seal. The V-type packing is divided into upper packing, middle packing and lower packing. The packing gland presses the V-type packing tightly.

[0009] A disc spring is provided between the packing gland and the pressure cap, and the pressure cap is threadedly connected to the valve cover.

[0010] Both the valve cover and the plug are equipped with anti-rotation screws.

[0011] This invention utilizes a combined integrated valve structure consisting of three needle valves and a drain plug. The two needle valves provide double-layer blocking and double-layer isolation functions in both forward and reverse directions, avoiding the need for independent installation of individual valves, which leads to multiple leakage points and installation difficulties, while also saving manufacturing costs. Furthermore, the needle valve located at the upstream end releases pipeline pressure, reduces leakage, avoids direct discharge, and facilitates pipeline system maintenance and supply shutdowns. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the valve body assembly structure of this utility model;

[0013] Figure 2 This is a schematic diagram of the valve cover connection structure of this utility model;

[0014] Figure 3 This is a schematic diagram of the packing installation structure of this utility model;

[0015] Figure 4 This is a schematic diagram of the anti-rotation structure of the valve cover of this utility model. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0017] Reference Figure 1A dual-blocking, dual-isolation combined needle valve includes a valve body 1. The valve body 1 has an inlet end 1-1 and an outlet end 2-2 on both sides. Multiple intersecting flow chambers are provided on the valve body between the inlet end 1-1 and the outlet end 2-2. The upper part of the valve body 1 has a first interface and a second interface, while the lower part has a third interface and a fourth interface, which are respectively used to install a first needle valve 2, a second needle valve 3, a third needle valve 4, and a screw plug 5. The first needle valve 2 and the second needle valve 3 control the opening and closing of the flow chambers to form a dual-blocking, dual-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, it blocks the medium from reaching the second flow chamber b. When the first needle valve 2 leaks, the medium reaches the second flow chamber b. The second needle valve 3 closes, blocking the medium from reaching the third flow chamber c, preventing the medium from flowing out from the outlet end 2-2, thus forming a dual-blocking function. The second needle valve 3 and the first needle valve 2 are closed simultaneously, 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, forming a double isolation function; the third needle valve 4 is simultaneously connected to the pipe at the outlet end and the discharge flow chamber, and a screw plug 5 is installed at the outlet of the discharge flow chamber.

[0018] Reference Figure 1 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 by fine-pitch threads and then contact each other through the conical surface 13. A pre-tightening force is provided by rotating the threads of the valve cover 6. The valve cover 6 and the valve body 1 contact each other through the conical surface 13, achieving a forced metal seal. The sealing surface angle of the conical surface 13 is 60°, and the contacting sealing surfaces are welded with hard alloy, forming the first seal between the valve cover 6 and the valve body 1.

[0019] Reference Figure 2 A flexible graphite-coated metal wire wound gasket 7 is provided between the valve cover 6 and the valve body 1. Rotating the valve cover 6 presses the flexible graphite-coated metal wire wound gasket 7, forming a second seal between the valve cover 6 and the valve body 1.

[0020] Reference Figure 3 A V-type packing seal is provided between the valve cover 6 and the valve stem. The V-type packing consists of an upper packing 8-1, a middle packing 8-2, and a lower packing 8-3. The packing gland 9 presses the V-type packing together. 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. Rotating the pressure cap 11 presses the disc spring 10 together, and the disc spring 10 provides a preload to the packing gland 9. The packing gland 9 then presses the V-type packing 8 together, ensuring the valve stem seal.

[0021] Reference Figure 4Both the valve cover 6 and the screw plug 5 are equipped with anti-rotation screws 12. The valve cover 6 and the screw plug 5 are regular hexagonal in shape. After the valve cover 6 and the screw plug 5 are rotated into place, the screws 12 are installed to fix the valve cover 6 and the screw plug 5, preventing the valve cover 6 and the screw plug 5 from rotating and causing the seal between the valve cover 6 and the screw plug 5 and the metal conical surface 13 of the valve body 1 to loosen and cause leakage.

Claims

1. A dual-blocking, dual-isolation combined needle valve, comprising a valve body, characterized in that, The valve body (1) has an inlet end (1-1) and an outlet end (2-2) on both sides. Multiple cross-flow chambers are provided between the inlet end (1-1) and the outlet end (2-2) and are interconnected. The upper part of the valve body (1) has a first interface and a second interface, while the lower part has a third interface and a fourth interface, corresponding to the installation of a first needle valve (2), a second needle valve (3), a third needle valve (4), and a screw plug (5), respectively. The first needle valve (2) and the second needle valve (3) control the opening and closing of the flow chambers 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, it blocks the medium 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) closes, blocking the medium from reaching the third flow chamber (c), preventing the medium from flowing out from the outlet end (2-2), thus forming a double-blocking function. The second needle valve (3) The first needle valve (2) is closed at the same time, 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), forming a double isolation function; the third needle valve (4) is simultaneously connected to the pipe 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. The dual-blocking, dual-isolation combined needle valve according to claim 1, characterized in that, 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) by fine thread and then contact each other through the conical surface (13).

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

4. The dual-blocking, dual-isolation combined needle valve according to claim 3, characterized in that, A V-type packing seal is provided between the valve cover (6) and the valve stem. The V-type packing is divided into upper packing (8-1), middle packing (8-2), and lower packing (8-3). The packing gland (9) presses the V-type packing.

5. A dual-blocking, dual-isolation 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 dual-blocking, dual-isolation combined needle valve according to claim 5, characterized in that, Both the valve cover (6) and the plug (5) are provided with anti-rotation screws (12).

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