High-temperature elastic butterfly valve with metal double-ring seal

Abstract

The present invention discloses a high-temperature elastic butterfly valve with a metal double-ring seal, which comprises a valve body, an upper valve stem, a valve plate, a lower valve stem, and a driving assembly; a gland is provided on the valve body, a convex ring embedded in the valve body is provided on the gland, an annular mounting groove is provided on one side of the outer ring of the convex ring close to the valve body, a double-ring seal is clamped on the convex ring, the double-ring seal comprises an outer ring clamped in the annular mounting groove, an inner ring clamped in the convex ring, and a connecting part connecting the outer ring and the inner ring, and a single-ring seal is provided on the convex ring on the side of the inner ring away from the valve body; an annular limiting groove is provided on the outer periphery of the part of the lower end of the lower valve stem passing through the valve body close to the end face of the valve body, the upper and lower side walls of the limiting groove are both inclined planes, the lower end of the valve body is connected with a tail end cover covering the lower valve stem, an annular positioning groove is provided on the tail end cover, an elastic split ring is movably arranged in the annular positioning groove, the elastic split ring is sleeved on the outer periphery of the lower valve stem, and a graphite ring is provided on the tail end cover on the outer periphery of the elastic split ring.

Description

Technical Field

[0001] The present invention relates to a high-temperature elastic butterfly valve with a metal double-ring seal. Background Art

[0002] Conventional high-temperature butterfly valves generally have a triple-eccentric structure. For this kind of metal cone-cone sealing structure, when the temperature difference of high-temperature media changes greatly, it is very difficult to meet the requirement of no visible leakage within the specified duration in the standard of GB / T13927-2008 "Industrial Valves - Pressure Test" due to the limitation of its structure. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a high-temperature elastic butterfly valve with a metal double-ring seal and good sealing performance.

[0004] To solve the above technical problem, the technical solution adopted by the present invention is: a high-temperature elastic butterfly valve with a metal double-ring seal, including a valve body. A medium passage is transversely provided through the valve body. A valve stem installation hole is longitudinally provided through the valve body. The upper valve stem is inserted into the part of the valve stem installation hole above the medium passage. A bearing is sleeved on the part of the upper valve stem in the valve stem installation hole close to the direct passage. A valve plate is connected to the part of the upper valve stem penetrating into the medium passage. A retaining ring is provided on the valve body. The retaining ring is provided with a convex ring embedded in the valve body. On one side of the outer circle of the convex ring close to the valve body, an annular installation groove is provided. A double-ring seal is clamped on the convex ring. The double-ring seal includes an outer ring clamped in the annular installation groove, an inner ring clamped in the convex ring, and a connecting part connecting the outer ring and the inner ring. A single-ring seal is provided on the convex ring on the side of the inner ring away from the valve body. Coil springs are provided inside both the double-ring seal and the single-ring seal. The single-ring seal has an interference fit such that the sum of the inner diameters of the single-ring seal and the inner ring of the double-ring seal in the free state is greater than the distance between the end face of the retaining ring close to the valve body and the valve body.

[0005] The lower valve stem is inserted into the part of the valve stem installation hole below the medium passage and is connected to the valve plate. A bearing is also sleeved on the part of the lower valve stem in the valve stem installation hole. On the outer periphery of the part of the lower valve stem extending out of the valve body near the end face of the valve body, an annular limiting groove is provided. The upper and lower side walls of the limiting groove are both inclined planes. A tail end cover covering the lower valve stem is connected to the lower end of the valve body. An annular positioning groove corresponding to the limiting groove is provided on the tail end cover. An elastic split ring is movably provided in the annular positioning groove. The elastic split ring is sleeved on the outer periphery of the lower valve stem. The inner diameter of the annular positioning groove is greater than the outer diameter of the circumscribed circle of the elastic split ring when it clamps the lower valve stem. A graphite ring is provided on the tail end cover on the outer periphery of the elastic split ring.

[0006] An annular mounting groove is provided on the side wall of the valve body where the valve stem mounting hole is located above the bearing. A packing is wound around the valve stem in the annular mounting groove. A packing pressing member for pressing the packing is connected to the valve body through a plurality of locking screws. A driving assembly for driving the upper valve stem to rotate is provided on the valve body. The packing pressing member includes a packing pressing sleeve sleeved on the valve stem for pressing the packing and a packing gland connected to the valve body through a plurality of the locking screws, disc springs and nuts. The top surface of the packing pressing sleeve is in a convex spherical shape, and a matching concave spherical surface is provided on the packing gland. Both the double-ring seal and the single-ring seal are formed by spinning a metal thin plate.

[0007] As a preferred solution, an interference amount is provided on the outer ring of the double-ring seal so that its outer diameter in the free state is greater than the distance between the corresponding side wall of the pressure ring and the valve body. An interference amount is also provided on the inner rings of the single-ring seal and the double-ring seal so that the sum of their outer diameters in the free state is greater than the distance between the end surface of the pressure ring close to the valve body and the valve body.

[0008] As a preferred solution, the interference amount on the outer ring of the double-ring seal is half of the sum of the interference amounts on the inner rings of the single-ring seal and the double-ring seal.

[0009] As a preferred solution, a connecting assembly for connecting the upper valve stem and the driving assembly is provided on the valve body.

[0010] As a preferred solution, the connecting assembly includes an extended column provided on the upper part of the valve body. An extended rod connected to the upper end of the upper valve stem is movably inserted through the extended column, and the upper end of the extended rod is connected to the output member of the driving assembly.

[0011] As a preferred solution, the extended column is connected to the mounting seat of the driving assembly, and a heat insulation pad is provided between them.

[0012] The beneficial effects of the present invention are:

[0013] The sealing pair of the high-temperature elastic pneumatic butterfly valve with a metal double-ring seal adopts a combination of a metal double-ring seal and a metal single-ring seal. The double-ring seal includes an outer ring stuck in the annular mounting groove, an inner ring stuck in the convex ring, and a connecting portion connecting the outer ring and the inner ring. A single-ring seal is provided on the side of the inner ring away from the valve body inside the convex ring. Coil springs are provided inside both the double-ring seal and the single-ring seal. An interference amount is provided on the single-ring seal so that the sum of the inner diameters of the single-ring seal and the inner ring of the double-ring seal in the free state is greater than the distance between the end surface of the pressure ring close to the valve body and the valve body. It is ensured that the gap generated by the sealing pair due to thermal expansion and contraction caused by the change of the medium temperature can be automatically compensated, and it has the function of automatic compensation for high-temperature elastic sealing.

[0014] Since a circular limit groove is provided on the outer periphery of the part where the lower end of the lower valve stem passes through the valve body near the end face of the valve body, and the upper and lower side walls of the limit groove are both inclined surfaces, the lower end of the valve body is connected with a tail end cover covering the lower valve stem, and a circular positioning groove corresponding to the limit groove is provided on the tail end cover. An elastic split ring is movably arranged in the circular positioning groove, the elastic split ring is sleeved on the outer periphery of the lower valve stem, the inner diameter of the circular positioning groove is larger than the diameter of the outer circle when the elastic split ring clamps the lower valve stem, and a graphite ring is arranged on the tail end cover on the outer periphery of the elastic split ring; the lower valve stem has reliable sealing, can withstand high temperature, and the upper and lower side walls of the limit groove are both inclined surfaces and cooperate with the elastic split ring to ensure the sealing effect when the lower valve stem moves up and down due to temperature difference changes.

[0015] The double-ring sealing ring and the single-ring sealing ring are respectively formed by spinning a thin metal plate, and have both elasticity and strength.

[0016] The upper sealing of the upper valve stem is a multi-layer combined seal of packing. The valve stem upper seal is achieved by combining and tightly pressing the sealing packing through a nut, a disc spring, a gland, and a packing sleeve. If the packing wears and a gap is generated between the packing and the upper valve stem, the elastic deformation of the disc spring is relied on to automatically compensate and tightly press the sealing packing. The gland and the packing sleeve are in spherical contact, which can ensure that the packing sleeve tightly presses the sealing packing evenly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the front view structural schematic diagram of the present invention.

[0018] Figure 2 is the side view sectional structural schematic diagram of the present invention.

[0019] Figure 3 is the Figure 2 enlarged structural schematic diagram of part I in the present invention.

[0020] Figure 4 is the sealing structural schematic diagram of the upper valve stem in the present invention.

[0021] Figure 5 is the sealing structural schematic diagram of the lower valve stem in the present invention.

[0022] Figure 6 is the structural schematic diagram of the elastic split ring in the present invention.

[0023] Figures 1 to 6 In the figure: 1. Tail end cover; 2. Graphite ring; 3. Elastic split ring; 4. Bearing; 5. Lower valve stem; 6. Valve plate; 7. Taper pin; 8. Upper valve stem; 9. Single-ring sealing ring; 10. Pressure ring; 11. Double-ring sealing ring; 12. Valve body; 13. Packing; 14. Packing sleeve; 15. Packing gland; 16. Locating pin; 17. Extended column; 18. Extended rod; 19. Heat insulation pad; 20. Driving assembly. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following will describe in detail the specific implementation embodiments of the present invention in conjunction with the accompanying drawings.

[0025] As Figures 1-6 shown, a high-temperature elastic butterfly valve with a metal double-ring seal includes a valve body 12. A medium passage that penetrates horizontally is provided on the valve body 12. A valve stem mounting hole that penetrates vertically is also provided on the valve body 12. The upper valve stem 8 is inserted into the part of the valve stem mounting hole above the medium passage. A bearing 4 is sleeved on the part of the upper valve stem 8 in the valve stem mounting hole close to the direct passage. A valve plate 6 is connected to the part of the upper valve stem 8 that penetrates into the medium passage through a tapered pin 7; A gland 10 is provided on the valve body 12. The gland 10 is provided with a convex ring embedded in the valve body 12. An annular mounting groove is provided on the side of the outer ring of the convex ring close to the valve body 12. A double-ring seal 11 is clamped on the convex ring. The double-ring seal 11 includes an outer ring clamped in the annular mounting groove, an inner ring clamped in the convex ring, and a connecting part connecting the outer ring and the inner ring. A single-ring seal 9 is provided on the side of the inner ring of the convex ring away from the valve body 12; Springs are provided inside both the double-ring seal 11 and the single-ring seal 9. The single-ring seal 9 has an interference fit such that the sum of the diameters of the single-ring seal 9 and the inner ring of the double-ring seal 11 in the free state is greater than the distance between the end face of the gland 10 close to the valve body 12 and the valve body 12; The interference fit of the outer ring 11 of the double-ring seal is half of the combined interference fit of the single-ring seal 9 and the inner ring 11 of the double-ring seal. Both the double-ring seal 11 and the single-ring seal 9 are formed by spinning metal sheets.

[0026] The lower valve stem 5 is inserted into the part of the valve stem mounting hole below the medium passage and is connected to the valve plate 6 through a tapered pin 7. A bearing 4 is also sleeved on the part of the lower valve stem 5 in the valve stem mounting hole; On the outer periphery of the part of the lower valve stem 5 that extends out of the valve body 12 near the end face of the valve body 12, an annular limit groove is provided. The upper and lower side walls of the limit groove are both inclined surfaces. A tail end cover 1 that covers the lower valve stem 5 is connected to the lower end of the valve body 12. An annular positioning groove corresponding to the limit groove is provided on the tail end cover 1. An elastic split ring 3 is movably provided in the annular positioning groove. The elastic split ring 3 is sleeved on the outer periphery of the lower valve stem 5. The inner diameter of the annular positioning groove is greater than the outer diameter of the circumscribed circle when the elastic split ring 3 clamps the lower valve stem 5. A graphite ring 2 is provided on the tail end cover 1 on the outer periphery of the elastic split ring 3;

[0027] An annular mounting groove is provided on the side wall of the valve stem mounting hole of the valve body 12 above the bearing 4. A packing 13 is wound around the upper valve stem 8 in the annular mounting groove. A packing pressing member for pressing the packing 13 is connected to the valve body 12 through a plurality of locking screws. A driving assembly 20 for driving the upper valve stem 8 to rotate is provided on the valve body 12.

[0028] The packing pressing member includes a packing gland 14 that sleeves the valve stem to press the packing 13, and a packing cover 15 that is connected to the valve body 12 through a plurality of the locking screws, disc springs and nuts. The top surface of the packing gland 14 is a convex spherical shape, and the packing cover 15 is provided with a matching concave spherical surface.

[0029] A connecting component for connecting the upper valve stem 8 and the driving component 20 is provided on the valve body 12. The connecting component includes an extended column 17 provided at the upper part of the valve body 12. A positioning pin 16 is provided between the extended column 17 and the valve body 12. An extended rod 18 connected to the upper end of the upper valve stem 8 is movably inserted through the extended column 17, and the upper end of the extended rod 18 is connected to the output member of the driving component 20. The extended column 17 is connected to the mounting seat of the driving component 20, and a heat insulation pad 19 is provided between the two.

[0030] Since both the double-ring seal 11 and the single-ring seal 9 are formed by spinning a metal thin plate and there is a preloading interference compensation amount during assembly, when the temperature changes, a gap and interference will occur between the valve plate 6 and the seal. At this time, the double-ring seal 11 will undergo elastic deformation, thereby squeezing the single-ring seal 9. Furthermore, the preloading interference compensation amount of the single-ring seal 9 increases or decreases, forming a preloading interference automatic compensation function to solve the sealing specific pressure that must be ensured for the interference amount of the seal pair with temperature change.

[0031] The metal double-ring seal high-temperature elastic butterfly valve made of this structure can meet the sealing requirements of each temperature range from normal temperature to 670 °C in terms of valve plate sealing, upper valve stem sealing and lower valve stem sealing. The sealing grade can reach the requirement of no visible leakage within the duration in the standard of GB / T 13927-2008 "Industrial Valves - Pressure Test", and it can be widely used in the diesel engine fuel gas pipeline of the ship power system to connect and cut off the medium.

[0032] The above embodiments only illustratively explain the principle and efficacy of the present invention and some applied embodiments, rather than limiting the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A high-temperature elastic butterfly valve with a metal double-ring seal, comprising a valve body. A transverse medium passage is provided on the valve body, and a longitudinally penetrating valve stem mounting hole is also provided on the valve body. The upper valve stem is inserted into the part of the valve stem mounting hole above the medium passage. A bearing is sleeved on the part of the upper valve stem close to the direct passage within the valve stem mounting hole. A valve plate is connected to the part of the upper valve stem penetrating into the medium passage. A gland is provided on the valve body, and it is characterized in that: The gland is provided with a convex ring embedded in the valve body. On one side of the outer ring of the convex ring close to the valve body, there is an annular mounting groove. A double-ring seal is clamped on the convex ring. The double-ring seal includes an outer ring clamped in the annular mounting groove, an inner ring clamped in the convex ring, and a connecting part connecting the outer ring and the inner ring. On the side of the inner ring away from the valve body inside the convex ring, there is a single-ring seal. Springs are provided inside both the double-ring seal and the single-ring seal. The single-ring seal has an interference fit such that the sum of the inner diameters of the single-ring seal and the inner ring of the double-ring seal in the free state is greater than the distance between the end face of the gland close to the valve body and the valve body. The lower valve stem is inserted into the part of the valve stem mounting hole below the medium passage and is connected to the valve plate. A bearing is also sleeved on the part of the lower valve stem located inside the valve stem mounting hole. On the outer periphery of the part of the lower valve stem extending out of the valve body near the valve body end face, there is an annular limit groove. The upper and lower side walls of the limit groove are both inclined planes. A tail end cover covering the lower valve stem is connected to the lower end of the valve body. At a position corresponding to the limit groove on the tail end cover, there is an annular positioning groove. An elastic split ring is movably arranged in the annular positioning groove. The elastic split ring is sleeved on the outer periphery of the lower valve stem. The inner diameter of the annular positioning groove is greater than the outer diameter of the elastic split ring when it clamps the lower valve stem. A graphite ring is provided on the tail end cover outside the elastic split ring. On the side wall of the valve body where the valve stem mounting hole is above the bearing, there is an annular mounting groove. Packing is wound around the upper valve stem in the annular mounting groove. A packing pressing member for pressing the packing is connected to the valve body through a plurality of locking screws. A driving assembly for driving the upper valve stem to rotate is provided on the valve body. The packing pressing member includes a packing pressing sleeve sleeved on the valve stem for pressing the packing and a packing pressing cover connected to the valve body through a plurality of the locking screws, disc springs, and nuts. The top surface of the packing pressing sleeve is in a convex spherical shape, and the packing pressing cover is provided with a matching concave spherical surface. The double-ring seal and the single-ring seal are both formed by spinning a metal thin plate.

2. The high-temperature elastic butterfly valve with a metal double-ring sealing ring according to claim 1, characterized in that: The outer ring of the double-ring seal has an interference fit such that its outer diameter in the free state is greater than the distance between the corresponding side wall of the gland and the valve body. The single-ring seal and the inner ring of the double-ring seal also have an interference fit such that the sum of their outer diameters in the free state is greater than the distance between the end face of the gland close to the valve body and the valve body.

3. The high-temperature elastic butterfly valve with a metal double-ring sealing ring according to claim 2, characterized in that: The interference fit of the outer ring of the double-ring seal is half of the sum of the interference fits of the single-ring seal and the inner ring of the double-ring seal.

4. A high-temperature elastic butterfly valve with a metal double-ring seal as claimed in claim 1, characterized in that: A connecting assembly for connecting the upper valve stem and the driving assembly is provided on the valve body.

5. The high-temperature elastic butterfly valve with a metal double-ring sealing ring as described in claim 4, characterized in that: The connecting assembly includes an extended column provided at the upper part of the valve body. An extended rod connected to the upper end of the upper valve stem is movably inserted into the extended column. The upper end of the extended rod is connected to the output member of the driving assembly.

6. The high-temperature elastic butterfly valve with a metal double-ring seal as claimed in claim 5, wherein: The extended column is connected to the mounting seat of the driving assembly, and a heat insulation pad is provided between them.

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