A built-in two-way self-sealing high-temperature and high-pressure valve

Abstract

The present invention discloses a built-in bidirectional self-sealing high-temperature and high-pressure valve, comprising a valve body, a valve seat, a valve cover, a back pressure cage, and a valve cage. A valve seat self-seal is arranged between the upper end of the back pressure cage and the lower end of the valve seat, a valve cage is arranged at the upper end of the valve seat, a valve cover self-sealing pressure ring is arranged at the upper end of the valve cage, and a valve cover self-seal is arranged between the upper end of the valve cover self-sealing pressure ring and the lower end of the valve cover; a pre-tightening flange, a four-way ring and a pre-tightening bolt are arranged on the valve cover, the pre-tightening flange is arranged between the valve cover and the four-way ring, the four-way ring and the pre-tightening flange cooperate to limit the movement of the pre-tightening flange in a direction away from the valve cover, and a pre-tightening bolt is arranged between the pre-tightening flange and the valve cover. The valve cover and the valve seat of the present invention both adopt a built-in self-sealing structure design. After the high-pressure medium is introduced, the seal is compressed, and the safety problem caused by the external leakage and internal leakage of the valve can be avoided, which effectively improves the economic efficiency of the unit operation and increases the stability, reliability and safety of the entire valve.

Description

Technical Field

[0001] The invention belongs to the technical field of valves, and in particular relates to a built-in two-way self-sealing high-temperature and high-pressure valve. Background Art

[0002] High temperature and high pressure valves are valves specially designed for use in high temperature and high pressure environments, and are mainly used in the fields of power, petrochemical, chemical, metallurgy, etc. Their main function is to control the flow of the medium, ensure the stable regulation and reliable shutoff of the valve, and ensure the safe and stable operation of the system. Due to the particularity of the operating environment and medium parameters of high temperature and high pressure valves, the safe and stable operation of the valve is particularly important. During the operation process, internal and external leakage of the valve will cause safety hazards to the entire system.

[0003] The existing high temperature and high pressure valves have various structural types, but the products of various manufacturers are similar. Figure 1 A high-temperature and high-pressure valve is disclosed: the valve seat is a movable valve seat, the valve cover is connected by bolts, and the valve cover seal and valve seat seal are compressed by tightening the valve cover bolts. Since the valve cover seal and valve seat seal are not pressure self-sealing structures, as the medium pressure increases, the valve cover bolts are always in a high-load tensile state under the action of the high-pressure medium, the valve cover bolts are slightly elongated, and the compression of the valve cover seal and valve seat seal is reduced, and the sealing reliability is reduced. Figure 2 Disclosed is a high-temperature and high-pressure valve: the valve seat is a welded valve seat, no valve cage is arranged between the valve cover and the valve seat, the valve core is in a cantilever state, and the valve cover seal adopts an external pressure self-sealing structure. The disadvantage of this structure is that the welded valve seat is difficult to inspect and repair, the valve core lacks the positioning constraint of the valve cage and is in a cantilever state, and the side-inlet airflow can easily cause the valve core to vibrate laterally, causing damage to the valve internals. In severe cases, it may cause pipeline resonance displacement, seriously affecting the safety of the unit.

[0004] With the upgrading of high-temperature and high-pressure valve parameters, the medium pressure and temperature parameters are gradually increasing. We urgently need a more stable, reliable and safe high-temperature and high-pressure valve. Summary of the invention

[0005] In order to solve the problems in the background technology, the purpose of the present invention is to provide a built-in bidirectional self-sealing high-temperature and high-pressure valve to meet the requirements of the fields of electricity, petrochemicals, chemical industry, metallurgy, etc. for long-term working stability, reliability and safety of high-temperature and high-pressure valves.

[0006] The technical solution of the present invention is: a built-in two-way self-sealing high-temperature and high-pressure valve, comprising a valve body, a valve seat, a valve cover, a back pressure cage, and a valve cage, wherein the back pressure cage is arranged at the bottom of the valve body, a valve seat self-seal is arranged between the upper end of the back pressure cage and the lower end of the valve seat, a valve cage is arranged at the upper end of the valve seat, a valve cover self-sealing pressure ring is arranged at the upper end of the valve cage, and a valve cover self-seal is arranged between the upper end of the valve cover self-sealing pressure ring and the lower end of the valve cover;

[0007] A pre-tightening flange, a four-way ring and pre-tightening bolts are arranged on the valve cover. The pre-tightening flange is arranged between the valve cover and the four-way ring. The four-way ring and the pre-tightening flange cooperate to limit the movement of the pre-tightening flange away from the valve cover. A pre-tightening bolt is arranged between the pre-tightening flange and the valve cover. The pre-tightening bolts are used to apply a force in a relative direction between the pre-tightening flange and the valve cover.

[0008] Preferably, stoppers are used between the back-pressure cage and the valve seat, as well as between the valve cover self-sealing pressure ring and the valve cover, and the valve cover self-seal and the valve seat self-seal are compressed by applying a pre-tightening force through pre-tightening bolts. After compression, an axial gap still remains between the back-pressure cage and the valve seat, as well as between the valve cover self-sealing pressure ring and the valve cover.

[0009] Preferably, a valve core is arranged inside the valve cage, and the upper end of the valve core is connected to a valve stem.

[0010] Preferably, sealing fillers are provided between the stop of the inner boss of the valve cover self-sealing pressure ring and the lower end of the valve cover, as well as on the inner sides of the upper end of the valve cover and the upper end of the valve stem.

[0011] Preferably, the cross-section of the valve cover self-sealing pressure ring is U-shaped.

[0012] Preferably, the back pressure cage is provided with a flow passage for the medium to enter the valve body from the back pressure cage and flow out from the outlet of the valve body.

[0013] Preferably, the cage is provided with a flow passage for the medium to flow from the valve body inlet into the cage.

[0014] Preferably, the flow passage on the back pressure cage is a circular hole.

[0015] Preferably, the flow passage on the cage has a circular hole at the bottom and a strip hole at the top.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] 1. The present invention adopts a built-in two-way self-sealing structure, and reserves an axial gap to allow the valve cover seal and the valve seat seal to be re-compressed. The high-temperature and high-pressure medium causes the valve cover seal and the valve seat seal to expand toward the axial gap and tend to be compressed. When the medium pressure increases, the compression force increases accordingly, and the seal is more reliable;

[0018] 2. The present invention achieves different back pressure effects by arranging the flow holes (number and size) of the non-constant back pressure cage, reduces the flow velocity of the medium between the valve core and the valve seat seal, and prevents the sealing surface from being eroded by the high-speed medium;

[0019] 3. The present invention adopts a four-ring fastening connection method, which avoids the problem of fatigue and failure of traditional bolt connections under the action of high-temperature and high-pressure media, ensures the stability of the internal component structure position of the valve during long-term operation, and improves the reliability of long-term operation of high-temperature and high-pressure valves and good sealing performance;

[0020] 4. The valve cover of the present invention cooperates with the valve cover self-sealing pressure ring and additional sealing fillers are provided at the upper and lower sections to prevent the medium from leaking outward along the valve stem. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or 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 labor.

[0022] Figure 1 A structural diagram of one of the prior arts;

[0023] Figure 2 It is a structural diagram of another prior art;

[0024] Figure 3 It is a structural diagram of the present invention;

[0025] Figure 4 This is the principle diagram of the valve seat self-sealing action;

[0026] Figure 5 This is the principle diagram of the valve cover self-sealing action;

[0027] Figure 6 It is a partial enlarged view of the valve cage of the present invention;

[0028] Figure 7 This is a partial enlarged view of the back pressure cage of the present invention;

[0029] Figure 8 It is a partial enlarged view of the sealing packing of the present invention;

[0030] 1. Valve body; 2. Back pressure cage; 3. Valve seat self-sealing; 4. Valve seat; 5. Valve cage; 51. Strip hole;

[0031] 52, round hole; 6, valve core; 7, valve cover self-sealing pressure ring; 8, valve cover self-sealing; 9, valve cover;

[0032] 10. Pre-tightening bolts; 11. Pre-tightening flange; 12. Four-way ring; 13. Sealing packing; 14. Valve stem. DETAILED DESCRIPTION

[0033] 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.

[0034] See also Figure 3 A built-in two-way self-sealing high-temperature and high-pressure valve comprises a valve body 1, a valve seat 4, a valve cover 9, a back pressure cage 2 and a valve cage 5. The back pressure cage 2 is arranged at the bottom of the valve body 1. A valve seat self-seal 3 is arranged between the upper end of the back pressure cage 2 and the lower end of the valve seat 4. A valve cage 5 is arranged at the upper end of the valve seat 4. A valve cover self-seal pressure ring 7 is arranged at the upper end of the valve cage 5. A valve cover self-seal 8 is arranged between the upper end of the valve cover self-seal pressure ring 7 and the lower end of the valve cover 9.

[0035] The valve cover 9 is provided with a pre-tightening flange 11, a four-way ring 12 and a pre-tightening bolt 10. The pre-tightening flange 11 is provided between the valve cover 9 and the four-way ring 12. The four-way ring and the pre-tightening flange 11 cooperate to limit the movement of the pre-tightening flange 11 away from the valve cover 9. The pre-tightening bolt 10 is provided between the pre-tightening flange 11 and the valve cover 9. The pre-tightening bolt 10 is used to apply a force in a relative direction between the pre-tightening flange 11 and the valve cover 9, so that the valve cover 9 can apply a downward force to the valve cover self-seal 8 and the valve seat self-seal 3. The fastening connection method using the four-way ring avoids the problem of fatigue and failure of the traditional bolt connection under the action of high-temperature and high-pressure media, ensures the stability of the internal component structure position of the valve during long-term operation, and improves the reliability and good sealing performance of the long-term operation of the high-temperature and high-pressure valve.

[0036] In a preferred embodiment of the present invention, stoppers are used for positioning between the back-pressure cage 2 and the valve seat 4, as well as between the valve cover self-sealing pressure ring 7 and the valve cover 9. The valve cover self-seal 8 and the valve seat self-seal 3 are compressed by applying a pre-tightening force through the pre-tightening bolts 10. After compression, an axial gap is still left between the back-pressure cage 2 and the valve seat 4, as well as between the valve cover self-sealing pressure ring 7 and the valve cover 9. The reserved axial gap can make the valve cover seal and the valve seat seal compressible again. The high-temperature and high-pressure medium causes the valve cover seal and the valve seat seal to expand toward the axial gap and be compressed. When the medium pressure increases, the compression force increases accordingly, and the seal is more reliable.

[0037] In a preferred embodiment of the present invention, the cross section of the valve cover self-sealing pressure ring 7 is U-shaped.

[0038] like Figure 4, install the back pressure cage 2 on the bottom surface of the valve body 1, then install the valve seat self-seal 3, fix the valve seat 4 by the pre-tightening bolts 10, and position the valve seat 4 and the back pressure cage 2 through the stopper. At the same time, the bottom of the valve seat cooperates with the valve seat self-seal 3 to squeeze the valve seat self-seal 3 downward, so that the valve seat self-seal 3 seals the lower part of the valve body 1. When high-temperature and high-pressure steam enters the valve, the high-pressure area in front of the sealing pair applies a downward force F3 to the valve seat 4; the low-pressure area behind the sealing pair applies an upward force F2 to the valve seat 4. According to the pressure difference before and after the valve seat sealing surface and the comparison of the two force-bearing areas of the upper and lower end surfaces of the valve seat, F3 is greater than F2, so the valve seat 4 is subjected to the downward force of the medium. The downward force on the valve seat 4 is transmitted to the valve seat self-seal 3. The greater the medium pressure, the greater the downward force (F3-F2) on the valve seat self-seal 3, which is more conducive to sealing.

[0039] like Figure 5 , install the bonnet self-sealing pressure ring 7 on the valve cage 5, then install the bonnet self-seal 8 and bonnet 9 in sequence, install the pre-tightening flange 11 on the top of the bonnet 9, and then install the four-way ring 12 inside the valve body 1, fix the pre-tightening flange 11 with the pre-tightening bolts 10, the four-way ring 12 is clamped inside the valve body 1, and the four-way ring 12 is set on the upper side of the pre-tightening flange 11, and the pre-tightening flange 11 is limited and fixed. At the same time, the bottom of the pre-tightening bolts 10 cooperates with the pre-tightening flange 11, and the bonnet 9 is pressed downward, so that the bonnet 9 seals the upper part of the valve body 1. At the same time, the pre-tightening flange 11 is reversely lifted by the pre-tightening bolts 10, and through the lower surface of the four-way ring 12, it plays a role of limiting. When high-temperature and high-pressure steam enters the valve, the bonnet 9 is subjected to an upward force F1, and the upward force F1 acts on the bonnet self-seal 8 through the bonnet self-sealing pressure ring 7. The greater the medium pressure, the greater the upward force F1 on the bonnet self-sealing pressure ring 7, and the more conducive to sealing. The four-ring 12 is composed of four half-rings, and the four half-rings are clamped inside the valve body 1 .

[0040] like Figure 6 In a preferred embodiment of the present invention, a flow channel is provided on the valve cage 5 for the medium to flow from the inlet of the valve body 1 into the valve cage 5. The flow channel at the lower part of the valve cage 5 is a circular hole 52, and the flow channel at the upper part of the valve cage is a strip hole 51. Different flow regulation requirements can be achieved through different hole arrangement methods.

[0041] like Figure 7 In a preferred embodiment of the present invention, a flow channel is provided on the back-pressure cage 2 for the medium to enter the interior of the valve body 1 from the back-pressure cage 2 and flow out from the outlet of the valve body 1. The flow channel of the back-pressure cage 2 is a circular hole 52. Different back-pressure effects can be achieved through different hole arrangement methods, reducing the medium flow rate between the valve core assembly hard seal 61 and the valve seat hard seal 41, and preventing the sealing surface from being eroded by high-speed medium.

[0042] like Figure 8In a preferred embodiment of the present invention, a valve core 6 is arranged inside the valve cage 5, and the upper end of the valve core 6 is connected to the valve stem 14. Sealing packing 13 is arranged between the inner boss stop of the valve cover self-sealing pressure ring 7 and the lower end of the valve cover 9, as well as on the inner side of the upper end of the valve cover 9 and the upper end of the valve stem 14, so as to prevent the medium from leaking outward along the valve stem 14.

[0043] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A built-in bidirectional self-sealing high-temperature and high-pressure valve, comprising a valve body (1), a valve seat (4), a valve cover (9), a back pressure cage (2), and a valve cage (5), characterized in that: The back pressure cage (2) is arranged at the bottom of the valve body (1); a valve seat self-seal (3) is arranged between the upper end of the back pressure cage (2) and the lower end of the valve seat (4); a valve cage (5) is arranged at the upper end of the valve seat (4); a valve cover self-seal pressure ring (7) is arranged at the upper end of the valve cage (5); and a valve cover self-seal (8) is arranged between the upper end of the valve cover self-seal pressure ring (7) and the lower end of the valve cover (9); The valve cover (9) is provided with a pre-tightening flange (11), a four-way ring (12) and a pre-tightening bolt (10); the pre-tightening flange (11) is arranged between the valve cover (9) and the four-way ring (12); the four-way ring and the pre-tightening flange (11) cooperate to limit the movement of the pre-tightening flange (11) in a direction away from the valve cover (9); a pre-tightening bolt (10) is arranged between the pre-tightening flange (11) and the valve cover (9); the pre-tightening bolt (10) is used to apply a force in a relative direction between the pre-tightening flange (11) and the valve cover (9); The back pressure cage (2) and the valve seat (4), as well as the valve cover self-sealing pressure ring (7) and the valve cover (9) are positioned by stoppers, and the valve cover self-seal (8) and the valve seat self-seal (3) are compressed by applying a pre-tightening force through the pre-tightening bolt (10), and after compression, an axial gap is still left between the back pressure cage (2) and the valve seat (4), as well as between the valve cover self-sealing pressure ring (7) and the valve cover (9); Sealing packing (13) is provided between the inner boss stop of the valve cover self-sealing pressure ring (7) and the lower end of the valve cover (9), and on the inner sides of the upper end of the valve cover (9) and the upper end of the valve stem (14); The valve seat self-seal (3) and the valve cover self-seal (8) expand and tighten toward the axial gap under the action of the pre-tightening force and the medium pressure.

2. A built-in two-way self-sealing high-temperature and high-pressure valve according to claim 1, characterized in that: A valve core (6) is arranged inside the valve cage (5), and a valve stem (14) is connected to the upper end of the valve core (6).

3. The built-in two-way self-sealing high-temperature and high-pressure valve according to claim 1, characterized in that: The valve cover self-sealing pressure ring (7) has a U-shaped ring cross section.

4. The built-in bidirectional self-sealing high-temperature and high-pressure valve according to claim 1, characterized in that: The back pressure cage (2) is provided with a flow passage for allowing the medium to enter the interior of the valve body (1) from the back pressure cage (2) and to flow out from the outlet of the valve body (1).

5. The built-in two-way self-sealing high-temperature and high-pressure valve according to claim 1, characterized in that: The valve cage (5) is provided with a flow passage for medium to flow from the inlet of the valve body (1) into the valve cage (5).

6. A built-in two-way self-sealing high-temperature and high-pressure valve according to claim 5, characterized in that: The flow passage on the back pressure cage (2) is a circular hole (52).

7. A built-in two-way self-sealing high-temperature and high-pressure valve according to claim 6, characterized in that: The flow passage on the valve cage (5) has a circular hole (52) at the bottom and a strip-shaped hole (51) at the top.

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