Duty gas control valve for gas system

Abstract

A duty gas control valve for a gas system comprises a valve body, a valve seat, a valve cover, a sleeve, a valve core and a bellows assembly, wherein the sleeve is installed in an installation cavity and sleeved on the outside of the valve seat, an inlet and an outlet are provided at both ends of the valve body to form a delivery channel, a double sealing structure is arranged between the valve core and the valve seat, a forward seal and a reverse seal are arranged between the valve core and the sleeve, the forward seal comprises a first grid ring, a forward balance seal ring, and a star ring, the reverse seal comprises a reverse balance seal ring and a second grid ring, the forward balance seal ring is provided with a metal spring and an O-ring with an opening facing upward, the reverse balance seal ring is provided with a metal spring and an O-ring with an opening facing downward, the star ring has a protruding sealing portion, and the sealing portion is sealed and connected with an inner bushing and a sleeve. The present invention is provided with a bidirectional sealing structure, which can achieve zero leakage under forward pressure and reverse full pressure.

Description

Technical Field

[0001] The invention relates to the field of gas systems, and in particular to a duty gas control valve for a gas system. Background Art

[0002] The gas system consists of a natural gas emergency shut-off valve, a natural gas control valve, a duty gas control valve, a natural gas relief valve and a natural gas burner. The duty gas control valve is also a leak-proof, fail-safe shut-off valve. In addition to controlling the mass flow of the duty gas, it is also part of the exhaust gas seal. In the premixed combustion mode, it ensures a reliable pilot flame. In addition, it is also hydraulically controlled and has a shut-off function. The existing duty gas control valve still has the disadvantage of being poorly sealed and prone to leakage, especially under some high-pressure and high-temperature conditions, where the sealing effect is even less than ideal. Summary of the invention

[0003] In view of this, the present invention provides a duty gas control valve for a gas system.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A duty gas control valve for a gas system comprises a valve body, a valve seat, a valve cover, a sleeve, a valve core and a bellows assembly, wherein the valve cover is mounted on the upper part of the valve body, a mounting cavity is formed between the valve cover and the valve body, the valve core is mounted at one end of the bellows assembly, the sleeve is mounted in the mounting cavity and sleeved on the outside of the valve seat, an inner sleeve is arranged between the valve core and the sleeve, an inlet and an outlet are arranged at both ends of the valve body, the inlet and the outlet are connected to form a delivery channel, the delivery channel is connected to the mounting cavity, a double sealing structure is arranged between the valve core and the valve seat, and a positive seal and a reverse seal are arranged between the valve core and the sleeve The forward seal comprises a first Gly ring, a forward balancing seal ring, and a star ring which are spaced apart from bottom to top; the reverse seal comprises a reverse balancing seal ring and a second Gly ring which are spaced apart from bottom to top; the forward balancing seal ring is provided with a metal spring with an opening facing upward and an O-ring located inside the metal spring; the reverse balancing seal ring is provided with a metal spring with an opening facing downward and an O-ring located inside the metal spring; the metal spring is compressed to accumulate elastic potential energy; the star ring has a protruding sealing portion, and the sealing portion is sealed and connected with the corresponding inner bushing and sleeve respectively.

[0006] Preferably, the inner sleeve is provided with a lower sealing groove, and the star ring is located in the lower sealing groove. The sealing portion of the star ring includes an upper sealing portion and a lower sealing portion symmetrically arranged in pairs, and an arc groove is formed between the upper sealing portion, the lower sealing portion and the sleeve. The upper sealing portion on the side in sealing contact with the sleeve has two sealing surfaces, one of which has a radial contact stress with the inner sleeve to form a primary seal, and the other has an axial contact stress with the sleeve to form a secondary seal.

[0007] Preferably, the upper sealing portion on the side of the star ring in sealing contact with the inner sleeve has two sealing surfaces, one of which has radial contact stress with the inner sleeve to form a primary seal, and the other has axial contact stress with the inner sleeve to form a secondary seal.

[0008] Preferably, an upper sealing groove is provided between the inner sleeve and the sleeve, the forward balancing sealing ring is sealingly installed between the sleeve and the valve core and is axially compressed and limited by the inner sleeve, and the reverse balancing sealing ring is sealingly installed in the upper sealing groove and an axial compression force is formed between its bottom and the inner sleeve.

[0009] Preferably, the duty gas control valve of the gas system is also provided with a valve core pressure plate, and the valve core pressure plate is fixedly installed on the upper part of the valve core through a connecting piece, a pressure plate sealing groove is provided on the outer periphery of the valve core pressure plate, and a valve core sealing groove is provided at a position of the valve core corresponding to the lower part of the positive balance sealing ring, the first grid ring is installed in the valve core sealing groove, and the second grid ring is installed in the pressure plate sealing groove.

[0010] Preferably, the double sealing structure includes an O-ring arranged between the valve body and the valve seat and a valve seat sealing ring arranged on the top of the valve seat, the valve seat sealing ring includes two parallel sealing rings and a connecting ring connected between the sealing rings, and the sealing ring located on the upper part has a double sealing surface, and the double sealing surface includes a vertically arranged annular sealing surface and a conical sealing surface intersecting the annular sealing surface.

[0011] Preferably, an annular groove is provided on the top of the valve seat, the sealing ring of the valve seat sealing ring located at the bottom is installed in the annular groove, and the sealing ring of the valve seat sealing ring located at the top is pressed between the sleeve and the top of the valve seat.

[0012] Preferably, the sleeve is provided with a reflux hole at a position corresponding to between the first grid ring and the valve seat sealing ring, and a reflux chamber is formed between the sleeve and the valve core at a position corresponding to between the first grid ring and the valve seat sealing ring, the reflux chamber is connected with the reflux hole, and the reflux hole is connected with the delivery channel.

[0013] The beneficial effects of the present invention are: a two-way sealing structure is set, and the cooperation between the valve core and the valve seat forms a guided seal, the positive balance seal ring cooperates with the star ring, and the star ring effectively compensates for the deformation of the positive balance seal ring, so as to achieve zero leakage under full positive pressure; the positive balance seal ring and the reverse balance seal ring cooperate with each other, so that the axial pressure between the valve core and the sleeve is balanced, and when the reverse pressure is fully pressed, the axial pressures between the positive balance seal ring and the reverse balance seal ring compensate each other, so as to achieve zero leakage under full reverse pressure; the upper sealing part of the star ring has radial contact stress and axial contact stress at the same time, forming a double seal, ensuring a better sealing effect, and at the same time, the angled radial contact stress and axial contact stress make the star ring always have a compensation force that is close to the sleeve and has an inclined angle with the sleeve, effectively preventing the curling deformation of the star ring, and having a better sealing effect after long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Attached Figure 1 It is a schematic diagram of the structure of the present invention;

[0016] Attached Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0017] Attached Figure 3 for Figure 1 Enlarged view of point B in the middle;

[0018] Attached Figure 4 for Figure 1 Enlarged view of point C in the middle;

[0019] Attached Figure 5 for Figure 1 Enlarged view of point D in the middle.

[0020] Attached Figure 6 for Figure 2 Enlarged view of point E in the middle. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] The present invention provides the following technical solutions:

[0024] As attached Figures 1 to 4 As shown, the present invention discloses a duty gas control valve for a gas system, comprising a valve body 1, a valve seat 2, a valve cover 3, a sleeve 4, a valve core 5 and a bellows assembly 51, wherein the valve cover 3 is mounted on the upper part of the valve body 1, a mounting cavity 6 is formed between the valve cover 3 and the valve body 1, the valve core 5 is mounted on one end of the bellows assembly 51, the sleeve 4 is mounted in the mounting cavity 6 and sleeved on the outside of the valve seat 2, an inner sleeve 7 is arranged between the valve core 2 and the sleeve 4, an inlet 8 and an outlet 9 are arranged at both ends of the valve body 1, and the inlet 8 and the outlet 9 are connected to form a delivery channel 10. The center line of the inlet 8 and the center line of the outlet 9 are located at the same level. The duty gas control valve for a gas system of the present invention is a stop valve. When the bellows assembly 51 is compressed up and down, the valve core is driven to move, thereby shutting off the delivery channel 10 or conducting the delivery channel 10. The delivery channel 10 is connected to the mounting cavity 6. The upper part of the bellows assembly 51 is connected to a valve stem, a packing is arranged between the valve stem and the valve cover, and a packing gland is arranged on the upper part of the packing. Bellows are used as sealing elements in situations where strict leakage control is required, such as when the medium is toxic or harmful liquid or gas. The valve cover adopts a bellows sealing structure, which can completely eliminate the possibility of process media leaking outward from the valve stem movement gap. One end of the bellows assembly is welded to the valve stem and the other end is welded to the valve core. Due to the deformability and outstanding anti-aging properties of the bellows assembly 51 itself, the weaknesses of the control valve, such as packing aging and temperature difference sensitivity, are completely overcome.

[0025] like Figure 2As shown, a double sealing structure 11 is arranged between the valve core 5 and the valve seat 2, and a forward seal 12 and a reverse seal 13 are arranged between the valve core 5 and the sleeve 4. The forward seal 12 includes a first grid ring 121, a forward balance seal ring 122, and a star ring 123 spaced from bottom to top, and the reverse seal 13 includes a reverse balance seal ring 131 and a second grid ring 132 spaced from bottom to top. The forward balance seal ring 122 is provided with a metal spring 1221 with an opening facing upward and an O-ring 1222 located inside the metal spring, and the reverse balance seal ring 131 is provided with a metal spring with an opening facing downward and an O-ring located inside the metal spring. When the forward balance seal ring and the reverse balance seal ring are installed, the metal springs are compressed to accumulate elastic potential energy so that the forward balance seal ring and the reverse balance seal ring can have the force to press the sleeve. The star ring 123 has a protruding sealing portion 1230, and the sealing portion 1230 is sealedly connected to the inner bushing 7 and the sleeve 4 at corresponding positions.

[0026] The sealing performance test of the valve was carried out, and the medium used was gas, the forward pressure was 38 barg, and the reverse pressure was 24 bar.g. The test results were all zero leakage. That is to say, by setting the bidirectional sealing structure, the valve core 5 and the valve seat 2 cooperate to form a guided seal, and the valve has good guiding performance and low noise when switching; the forward balance seal ring 122 cooperates with the star ring 123, and the star ring 123 effectively compensates for the deformation of the forward balance seal ring 122, and achieves zero leakage under full forward pressure; the forward balance seal ring and the reverse balance seal ring 131 cooperate with each other, so that the axial pressure between the valve core 5 and the sleeve 4 is balanced, and when the reverse pressure is fully pressed, the axial pressure between the forward balance seal ring 122 and the reverse balance seal ring 131 compensates for each other, and can achieve zero leakage under full reverse pressure.

[0027] The inner sleeve 7 is provided with a lower sealing groove 71, and the star ring 123 is located in the lower sealing groove 71. The sealing part 1230 of the star ring 123 includes an upper sealing part 1231 and a lower sealing part 1232 which are symmetrically arranged in pairs. That is to say, the star ring 123 has four sealing parts, which are arranged correspondingly in the upper and lower parts. The upper sealing part 1231 is located in the upper part, and the lower sealing part 1232 is located in the lower part. An arc groove 14 is formed between the upper sealing part 1231, the lower sealing part 1232 and the sleeve 4. The upper sealing part 1231 on the side of the sealing contact with the sleeve 4 has two sealing surfaces, one of which has a radial contact stress with the inner sleeve 7 to form a primary seal, and the other sealing surface 1231-2 has an axial contact stress with the sleeve 4 to form a secondary seal. After such arrangement, pressure compensation can be performed in both radial and axial directions, and the combined force of the two sealing surfaces, the inner bushing 7 and the sleeve 4 can always press the sleeve 5 obliquely upward. After such arrangement, compared with a sealing structure with only axial stress or radial stress, its sealing performance is better and the structure is more stable.

[0028] like Figure 2 As shown, the upper sealing portion 1231 on the side of the star ring 123 in sealing contact with the inner sleeve 7 has two sealing surfaces, one of which has radial contact stress with the inner sleeve 7 to form a primary seal, and the other has axial contact stress with the inner sleeve 7 to form a secondary seal. After such arrangement, since the sealing portion 1231 of the star ring 123 has both axial contact stress and radial contact stress, there is a better pressure distribution on the sealing portion 1231, thereby obtaining a very good sealing effect; an arc groove 14 is formed between the upper sealing portion 1231, the lower sealing portion 1232 and the sleeve 4, and the formation of the sealing groove 14 helps to lubricate the cavity and improve the starting condition; the upper sealing portion of the star ring has both radial contact stress and axial contact stress to form a double seal, thereby ensuring a better sealing effect; at the same time, the angled radial contact stress and axial contact stress enable the star ring to always have a compensation force that is close to the sleeve 4 and forms an inclined angle with the sleeve 4, thereby effectively preventing the curling and deformation of the star ring and achieving a better sealing effect even after long-term use.

[0029] In order to enable the sealing system to maintain better sealing performance under low pressure and corrosion resistance conditions, the present invention improves the design of the V-shaped packing in the prior art, such as Figure 5As shown, the V-shaped packing is changed into a U-shaped groove 23, and a dustproof sealing ring and an O-ring are placed on the packing gland. Specifically, this structure prevents impurities attached to the exposed surface of the valve stem from entering the stuffing box with the valve stem and damaging the valve stem and the packing, while also playing an auxiliary sealing role. This structure makes the radial contact pressure between the packing and the valve stem more evenly distributed along the axial direction, so that each ring of packing can play a sealing role and is easy to achieve sealing. In the middle of the valve stem, a thicker liquid film is easily formed, which plays a good lubricating role, can reduce the wear of the packing on the valve stem, and extend the service life of the valve. Practice has proved that the improved packing has better elasticity and is more conducive to sealing.

[0030] Specifically, an upper sealing groove 15 is provided between the inner bushing 7 and the sleeve 4, the forward balancing seal ring 122 is sealingly installed between the sleeve 4 and the valve core 5 and is axially compressed and limited by the inner bushing 7, and the reverse balancing seal ring 131 is sealingly installed in the upper sealing groove 15 and an axial compression force is formed between its bottom and the inner bushing 7. The forward balancing seal ring 122 has a large pre-pressure mainly at its lower opening, and the directional balancing seal ring 131 mainly forms a large pre-pressure at its upper opening. The forward balancing seal ring 122, the reverse balancing seal ring 131 and the star ring 123 cooperate to form better guiding performance while compensating for pressure, so that the radial force and axial force of the sleeve 4 and the valve core 5 are balanced, the structure is more stable, and there will be no severe wear on one side, and the service life of the valve is longer.

[0031] The duty gas control valve of the gas system is also provided with a valve core pressure plate 16, and the valve core pressure plate 16 is fixedly installed on the upper part of the valve core 5 through a connecting piece. A pressure plate sealing groove 17 is provided on the outer periphery of the valve core pressure plate 16, and a valve core sealing groove 18 is provided on the valve core 5 at a position corresponding to the lower part of the positive balance sealing ring 122. The first grid ring 121 is installed in the valve core sealing groove 18, and the second grid ring 132 is installed in the pressure plate sealing groove 17.

[0032] like Figure 3 As shown, the double sealing structure 11 includes an O-ring 110 disposed between the valve body 1 and the valve seat 2 and a valve seat sealing ring 111 disposed on the top of the valve seat 2. The O-ring 110 is mainly used to seal the outer side of the valve seat 3 and the valve body 1. In a specific implementation, Figure 3As shown, a groove for accommodating an O-ring 110 is provided in the valve body 1. The valve seat sealing ring 111 includes two sealing rings 1112 arranged in parallel and a connecting ring 1113 connected between the sealing rings 1112. The sealing ring 1112 located at the upper part has a double sealing surface, and the double sealing surface includes a vertically arranged annular sealing surface 20 and a conical sealing surface 21 intersecting the annular sealing surface 20. The conical sealing surface has a cone intersection of 60° in the vertical direction, and such an arrangement can maintain better structural stability. Specifically, an annular groove is provided at the top of the valve seat 2, and the sealing ring 1112 located at the lower part of the valve seat sealing ring 111 is installed in the annular groove, and the sealing ring 1112 located at the upper part of the valve seat sealing ring 1112 is pressed between the sleeve 4 and the top of the valve seat 2.

[0033] In order to facilitate the reflux of the medium flowing into the sleeve 4 and the valve core 5 due to high pressure, the sleeve 4 is provided with a reflux hole 19 at a position corresponding to the position between the first grid ring 121 and the valve seat 2 sealing ring, and a reflux chamber 22 is formed between the sleeve 4 and the valve core 5 at a position corresponding to the position between the first grid ring 121 and the valve seat sealing ring 111, and the reflux chamber 22 is connected to the reflux hole 19, and the reflux hole 19 is connected to the delivery channel 10. The reflux hole 19 can be as shown in the appendix of the present application. Figure 4 As shown, multiple reflux holes are provided, and the multiple reflux holes are opened in parallel along the horizontal direction. After such an arrangement, the refluxed medium has a smaller impact on the valve core 5, thereby achieving pressure protection for the valve core 5.

[0034] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A duty gas control valve for a gas system, comprising a valve body, a valve seat, a valve cover, a sleeve, a valve core and a bellows assembly, wherein the valve cover is mounted on the upper part of the valve body, a mounting cavity is formed between the valve cover and the valve body, the valve core is mounted at one end of the bellows assembly, the sleeve is mounted in the mounting cavity and sleeved on the outside of the valve seat, an inner sleeve is arranged between the valve core and the sleeve, an inlet and an outlet are arranged at both ends of the valve body, the inlet and the outlet are connected to form a delivery channel, the delivery channel is connected to the mounting cavity, and the characteristics are: A double sealing structure is arranged between the valve core and the valve seat, and a forward seal and a reverse seal are arranged between the valve core and the sleeve. The forward seal includes a first grid ring, a forward balancing seal ring, and a star ring which are spaced apart from bottom to top; the reverse seal includes a reverse balancing seal ring and a second grid ring which are spaced apart from bottom to top; the forward balancing seal ring is provided with a metal spring with an opening facing upward and an O-ring located inside the metal spring; the reverse balancing seal ring is provided with a metal spring with an opening facing downward and an O-ring located inside the metal spring; the metal spring is compressed to accumulate elastic potential energy; the star ring has a protruding sealing portion, and the sealing portion is respectively sealed with the corresponding inner sleeve and sleeve.

2. The duty gas control valve of the gas system according to claim 1, characterized in that: The inner sleeve is provided with a lower sealing groove, and the star ring is located in the lower sealing groove. The sealing part of the star ring includes an upper sealing part and a lower sealing part symmetrically arranged in pairs. An arc groove is formed between the upper sealing part, the lower sealing part and the sleeve. The upper sealing part on the side in sealing contact with the sleeve has two sealing surfaces, one of which has a radial contact stress with the inner sleeve to form a primary seal, and the other has an axial contact stress with the sleeve to form a secondary seal.

3. The duty gas control valve of the gas system according to claim 2, characterized in that: The upper sealing part on the side where the star ring contacts the inner sleeve in sealing has two sealing surfaces, one of which has radial contact stress with the inner sleeve to form a primary seal, and the other has axial contact stress with the inner sleeve to form a secondary seal.

4. The duty gas control valve of the gas system according to claim 1 or 2, characterized in that: An upper sealing groove is arranged between the inner sleeve and the sleeve, the forward balancing sealing ring is sealingly installed between the sleeve and the valve core and is axially compressed and limited by the inner sleeve, and the reverse balancing sealing ring is sealingly installed in the upper sealing groove and an axial compression force is formed between its bottom and the inner sleeve.

5. The duty gas control valve of the gas system according to claim 2, characterized in that: The duty gas control valve of the gas system is also provided with a valve core pressure plate, which is fixedly installed on the upper part of the valve core through a connecting piece, and a pressure plate sealing groove is provided on the outer periphery of the valve core pressure plate. The valve core is provided with a valve core sealing groove at a position corresponding to the lower part of the positive balance sealing ring, the first grid ring is installed in the valve core sealing groove, and the second grid ring is installed in the pressure plate sealing groove.

6. The duty gas control valve of the gas system according to claim 1 or 2, characterized in that: The double sealing structure includes an O-ring arranged between the valve body and the valve seat and a valve seat sealing ring arranged on the top of the valve seat. The valve seat sealing ring includes two parallel sealing rings and a connecting ring connected between the sealing rings. The sealing ring located on the upper part has a double sealing surface, which includes a vertically arranged annular sealing surface and a conical sealing surface intersecting the annular sealing surface.

7. The duty gas control valve of the gas system according to claim 6, characterized in that: An annular groove is arranged on the top of the valve seat, and the sealing ring of the valve seat sealing ring located at the bottom is installed in the annular groove, and the sealing ring of the valve seat sealing ring located at the top is pressed between the sleeve and the top of the valve seat.

8. The duty gas control valve of the gas system according to claim 6, characterized in that: The sleeve is provided with a reflux hole at a position corresponding to between the first grid ring and the valve seat sealing ring, and a reflux chamber is formed between the sleeve and the valve core at a position corresponding to between the first grid ring and the valve seat sealing ring, the reflux chamber is connected with the reflux hole, and the reflux hole is connected with the delivery channel.

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