High-performance sealing lining plastic butterfly valve

Abstract

The utility model discloses a high-performance sealing lining plastic butterfly valve, and belongs to the utility model and creation of anti-corrosion butterfly valves. The utility model aims to solve the problem that the existing high-corrosivity media, air pipe galleries, process devices, used steel lining fluoroplastic butterfly valves (anti-corrosion butterfly valves for short) and chemical engineering devices with highly corrosive substances have very strict requirements on the sealing performance of the anti-corrosion butterfly valves, and due to the fact that on the toxic and harmful special working conditions, the sealing performance of the anti-corrosion butterfly valves cannot be influenced once the valves leak out of the media. The valve can be replaced only if unsafe factors are caused and the device is stopped. On-site investigation shows that the medium leakage reason of an existing anti-corrosion butterfly valve is that O-shaped rings arranged at the upper end and the lower end of a butterfly plate fail in sealing, and the O-shaped sealing rings eroding a valve shaft fail, so that the medium leaks out of middle holes of an upper valve body and a lower valve body. Therefore, according to the novel anti-corrosion butterfly valve, the upper end and the lower end of the butterfly plate are provided with O-shaped rings for sealing, the upper valve rod and the lower valve rod are provided with packing sealing structures, and the problem of medium leakage is solved.

Description

Technical Field

[0001] The utility model discloses a high-performance sealed plastic-lined butterfly valve, which belongs to the invention of anti-corrosion butterfly valves. The invention relates to valves for anti-corrosion of process pipelines in petrochemical, power plants, metallurgy, pharmaceutical plants and other departments. Background Art

[0002] The main task of this utility model is to target the existing highly corrosive media, whose aerial pipe gallery and process equipment are all equipped with pipelines, steel-lined fluoroplastic butterfly valves (referred to as anti-corrosion butterfly valves) used on the pipelines, and chemical equipment with corrosive and highly toxic substances. The sealing performance requirements of the anti-corrosion butterfly valve are very strict, because in these toxic and harmful special working conditions, once the valve leaks the medium, it will cause unsafe factors, and then cause the device to stop before the valve can be replaced. It can be seen how important "anti-corrosion butterfly valves" are in safe production operations. It is known that such parking will cause certain economic losses to the enterprise. In order to avoid accidental parking, new innovative breakthroughs must be made in the valve design structure to completely solve the key technical problems of the anti-corrosion butterfly valve.

[0003] Based on the above problems, the utility model conducts field research on the working condition device used in the anti-corrosion butterfly valve. The reason for the leakage of the medium of the existing anti-corrosion butterfly valve is that the "O" ring seal set at the upper and lower ends of the butterfly plate fails, and then the "O" ring seal of the valve shaft is corroded and fails, resulting in the leakage of the medium in the upper and lower valve bodies. It can be seen that the structure only relies on two "O" rings to prevent the leakage of toxic chemicals, which is extremely unscientific and unreliable. There are still defects in the sealing structure, which is the disadvantage of the anti-corrosion butterfly valve. For this reason, the present invention develops a high-performance sealing new "anti-corrosion butterfly valve", which not only sets an "O" ring sealing structure at the upper and lower ends of the butterfly plate, but also sets a "V"-shaped packing structure at the upper and lower valve stems of the butterfly plate. The design of the "V"-shaped packing structure is very unique. It designs the upper and lower valve stem through holes of the lining plastic valve seat into a long neck shape, and sets a "V"-shaped packing base at the top of the neck, and then a "V"-shaped combined packing is set on it, so that the packing base and the combined packing are firmly combined to form an effective and reliable seal. This prevents the medium from leaking out, ensures the "anti-corrosion butterfly valve" has reliable quality and long service life, and eliminates losses caused by abnormal failures and shutdowns. Summary of the invention

[0004] The utility model "a high-performance sealed plastic-lined butterfly valve" mainly includes: a gland cover; a top screw; a lower valve stem; a lower stuffing box; a lower valve body; an O-ring; a butterfly plate; a plastic-lined valve seat; an upper stuffing box; an upper valve body; an upper valve stem; a gland; a pressure plate; a worm gear box; and a handwheel.

[0005] A "V"-shaped combined upper stuffing box is arranged in the middle hole of the upper valve body, an upper valve stem and a compression sleeve are arranged in the middle hole of the upper valve body, and a pressure plate is arranged outside the hole; a concave valve stem is arranged at the packing of the upper valve stem, and fluoroplastic is wrapped on the concave valve stem; a valve shaft is arranged on the upper part of the fluoroplastic;

[0006] A "V"-shaped combined lower stuffing box is arranged in the middle hole of the lower valve body, and a lower valve stem, a compression sleeve cover and a top screw are also arranged in the middle hole of the lower valve body; the lower valve stem is designed to have metal shafts at both ends, and the middle stuffing section is designed to be concave, and the concave part is lined with fluoroplastics to prevent corrosive media from corroding the metal;

[0007] The upper end of the butterfly plate is designed with a countersunk hole, which fits tightly with the upper valve stem and is then welded together; the lower end of the butterfly plate is designed with a countersunk hole with a valve shaft, which rotates in coordination with the valve shaft of the lower valve stem; the butterfly plate and the packing section of the upper valve stem are all lined with fluoroplastics to make them corrosion-resistant;

[0008] The valve shaft lining of the lower valve stem is provided with a double sealing "O" ring to strengthen the sealing shaft hole gap to prevent the medium from invading the metal shaft chamber and affecting the life of the valve;

[0009] The plastic-lined valve seat is designed as a cylinder with flanges at both ends. A long-necked packing base is provided at the upper and lower valve stem through-holes of the cylinder. The top of the packing base neck is designed as a "V"-shaped packing, and a "V"-shaped combined packing is arranged on it to form a high-performance sealing box; the high-performance sealing box is composed of a packing base, which is called an inner ring, and a spare middle ring and an outer ring.

[0010] The present invention combines the upper and lower valve bodies into one by screws, and the plastic-lined valve seat is embedded inside. A V-shaped combined packing is arranged inside the middle hole of the upper and lower valve bodies. The V-shaped packing is divided into three rings: inner, middle and outer. The inner ring is arranged on the plastic-lined valve seat body, and a long-necked V-shaped inner ring (regarded as a packing base) is arranged at the upper and lower valve stem holes of the plastic-lined valve seat. It forms a stuffing box with three middle rings and one outer ring, wherein the three middle rings and one outer ring are all processed spare parts. When assembled, they are placed in the structural order to form an effective seal. When the anti-corrosion butterfly valve is operating in normal production, if the valve medium leaks out, the pre-tightening pressure plate or the pressure sleeve cover can be used to apply pressure to the upper and lower pressure sleeves, so that the combined packing is forced to hold the valve stem tightly to prevent the medium from leaking out, thereby avoiding the device from stopping. In addition, the present invention also has innovations in the overall structure of the butterfly plate. The upper end of the butterfly plate is designed to have a countersunk hole that fits tightly with the upper valve stem and then welded together. The upper valve stem filler is machined into a concave shape, and the lower end of the butterfly plate is designed to have a countersunk hole with a valve shaft. After that, the butterfly plate and the valve stem (filler section) are all lined with fluoroplastics to achieve corrosion resistance. At the same time, the matching lower valve stem is designed to have metal shafts at both ends, the middle filler section is designed to be concave, and the concave part is lined with fluoroplastics to prevent corrosive media from corroding the metal. The lower valve stem is also provided with a top screw structure, which can adjust the center position of the butterfly plate and prevent the butterfly plate from sinking. The upper and lower pressing sleeves of the present invention have the function of positioning the shaft sleeves, that is, the upper part of the upper valve stem lining (metal part) forms a rotational fit with the upper pressing sleeve, and the countersunk hole at the lower end of the butterfly plate and the inserted lower valve stem (metal part) also form a rotational fit, so the butterfly plate is firmly positioned by the upper and lower valve shafts and the pressing sleeve to form a fixed butterfly valve; the lower valve stem is locked by the packing, the pressing sleeve cover and the top screw, and the lower valve stem does not rotate, and is in a static sealing state, so the sealing effect is good. The reason why the present invention uses packing to seal the upper and lower valve stems and regards the upper and lower valve stems as valve shafts is that the packing structure is reliable and durable. Once the valve medium leaks out, there is no need to stop the valve and replace it. As long as the pre-tightening packing pressure plate or the pressing sleeve cover is adopted, the medium leakage problem can be solved. In addition, based on innovation, the present invention not only retains the structure of the "O" rings at the upper and lower ends of the original butterfly plate, but also has a double sealing "O" ring at the valve shaft lining part of the lower valve stem. This structure is a new type of first seal, and the second is a new type of packing seal. Together, the upper and lower valve stems each form a two-seal structure. Therefore, the sealing performance of the new anti-corrosion butterfly valve has been innovated, and the leakage problem has been completely solved. Therefore, the valve has a clever design, a reasonable structure, a long service life, and a double sealing effect. It is currently an ideal and practical product. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1This is the main cross-sectional view of the structure of the utility model. In the figure: 1. Gland cover; 2. Top screw; 3, 9, 20. Screws; 4. Lower valve stem; 5. Lower stuffing box; 6. Lower valve body; 7, 11. O-ring; 8. Butterfly plate; 10. Butterfly plate lining; 12. Plastic-lined valve seat; 13. Upper stuffing box; 14. Upper valve body; 15. Upper valve stem; 16. Gland; 17. Pressure plate; 18. Nut; 19. Stud; 21. Worm gear box; 22. Handwheel. As shown in the attached Figure 1 shown.

[0012] Figure 2 yes Figure 1 The cross-sectional view of the structure of the AA valve when it is closed. In the figure: 7, 11. O-ring; 8. Butterfly plate; 9. Screw; 12. Plastic-lined valve seat; 23. Expanding rubber pad. Figure 2 shown.

[0013] Figure 3 yes Figure 1 A partial enlarged structural cross-sectional view of the upper end I of the middle butterfly plate 8. In the figure: 15. Upper valve stem; 13. Upper stuffing box; 14. Upper valve body; 12. Plastic-lined valve seat; 11. O-ring; 8. Butterfly plate. Figure 3 shown.

[0014] Figure 4 yes Figure 1 A partial enlarged structural cross-sectional view of the lower end II of the middle butterfly plate 8. In the figure: 4. Lower valve stem; 8. Butterfly plate; 7. O-ring; 12. Plastic-lined valve seat; 6. Lower valve body; 5. Lower stuffing box. Figure 4 shown.

[0015] Figure 5 yes Figure 1 Structural cross-sectional view of the middle-lined plastic valve seat 12. In the figure: III is an important position for expressing a part.

[0016] Figure 6 yes Figure 5 A partial enlarged view of the lower mesopore long neck shape III.

[0017] The valve body of the utility model is divided into two parts, an upper part and an lower part. Both sides of the upper valve body 14 and the lower valve body 6 are provided with convex grippers, screw holes and thread holes are provided on the convex grippers, screws 9 are inserted into the screw holes and screwed in the thread holes, and the upper and lower valve bodies 14 and 6 are integrated into one; in addition, the butterfly plate 8 and the upper valve stem 15 are integrated by welding, and the lower valve stem 4 and the butterfly plate 8 are separate components, and the two cooperate with each other in a dynamic and static manner and have a tolerance gap for rotation. DETAILED DESCRIPTION

[0018] The working principle of the embodiments of the present utility model will be described below in conjunction with the accompanying drawings.

[0019] 1. When the valve is closed:

[0020] Turn the hand wheel 22 of the worm gear box 21 clockwise to drive the upper valve stem 15 to rotate clockwise, and then the butterfly plate 8 rotates synchronously to close the valve. Figure 1 and attached Figure 2 As shown. During this process, when the butterfly plate 8 is in the closed state, the circular edge of the butterfly plate 8 is tightly embraced by the plastic-lined valve seat 12 to form a seal. This is because the back of the plastic-lined valve seat 12 is provided with an expansion rubber pad 23, which is squeezed to generate a pre-tightening force, thereby achieving a sealing effect. In addition, the lower valve stem 4 is firmly pressed and fixed by the compression sleeve cover 1 and the lower stuffing box 5, and then adjusted by the top screw 2 to support the butterfly plate 8 to move downward, so that the role of the lower valve stem 4 can be regarded as the fixed axis of the butterfly plate 8. The countersunk hole of the butterfly plate 8 cooperates with the valve shaft of the lower valve stem 4, and both are clearance-positioned to cooperate with the rotation of the butterfly plate 8. The upper and lower end seals of the butterfly plate 8 are sealed by an O-ring 11, 7, and now an additional stuffing box 13, 5 is provided. Therefore, the utility model "anti-corrosion butterfly valve" has a double-channel reliable sealing effect. As shown in the attached Figure 1 and attached Figure 2 shown.

[0021] 2. When the valve is open:

[0022] Turn the hand wheel 22 counterclockwise, and similarly drive the upper valve stem 15 to rotate counterclockwise, and turn the butterfly plate 8 to the open position. At this time, the medium flow is maximum, and the valve pressure difference is reduced, which is beneficial to the sealing of the upper and lower valve stems 15 and 4. Especially after the double sealing structure is provided, when the butterfly plate 8 is in the open position, the medium is guaranteed not to leak out, so the sealing is tight, reliable and has a long service life. Figure 1 and attached Figure 2 shown.

[0023] The utility model "a high-performance sealed plastic-lined butterfly valve" is a change and improvement of the structural performance of the existing "steel-lined fluoroplastic butterfly valve". This new type of anti-corrosion butterfly valve completely solves the outstanding problems of medium leakage, valve weakness, poor sealing quality, short service life, etc.

Claims

1. A high-performance sealed plastic-lined butterfly valve, mainly comprising: Press sleeve The valve body comprises a cover (1); a top screw (2); a lower valve stem (4); a lower stuffing box (5); a lower valve body (6); an O-ring (7, 11); a butterfly plate (8); a plastic-lined valve seat (12); an upper stuffing box (13); an upper valve body (14); an upper valve stem (15); a pressing sleeve (16); a pressing plate (17); a worm gear box (21); and a hand wheel (22), and is characterized in that: A "V"-shaped combined upper stuffing box (13) is arranged in the middle hole of the upper valve body (14), an upper valve stem (15) and a compression sleeve (16) are arranged in the middle hole of the upper valve body (14), and a pressure plate (17) is arranged outside the hole; a concave valve stem is arranged at the stuffing of the upper valve stem (15), and a fluoroplastic is wrapped on the concave valve stem, and a valve shaft is arranged on the upper part of the fluoroplastic; A "V"-shaped combined lower stuffing box (5) is arranged in the middle hole of the lower valve body (6), and a lower valve stem (4), a compression sleeve cover (1) and a top screw (2) are also arranged in the middle hole of the lower valve body (6); the lower valve stem (4) is designed to have metal shafts at both ends, and the middle stuffing section is designed to be concave, and the concave part is lined with fluoroplastics; The upper end of the butterfly plate (8) is designed with a countersunk hole to be tightly fitted with the upper valve stem (15) and then welded together; the lower end of the butterfly plate (8) is designed with a countersunk hole with a valve shaft, which rotates in coordination with the lower valve stem (4); in addition, the packing sections of the butterfly plate (8) and the upper valve stem (15) are all lined with fluoroplastics; The valve shaft lining part of the lower valve stem is provided with double sealing O-rings (7, 11) for strengthening the sealing shaft hole gap; The plastic-lined valve seat (12) is designed as a cylinder with flanges at both ends. A long-necked packing base is provided at the through-holes of the upper and lower valve stems (15, 4) of the cylinder. The top of the neck of the packing base is designed as a V-shaped packing, and a V-shaped combined packing is arranged on it to form a high-performance sealing box. The high-performance sealing box is composed of a packing base, namely an inner ring, and a spare middle ring and an outer ring.

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