A valve disc step seal safety valve

Abstract

The utility model discloses a valve clack step type sealed safety valve relates to safety valve technical field, can avoid bellows use, can realize the novel safety valve structure of effective, reliable sealing between valve cavity and spring cavity simultaneously. The outer periphery of valve clack is provided with annular step, and the sealing element is sleeved on the step, the bottom of spring cavity forms bottom annular surface, when safety valve opens, and the sealing element rises and contacts bottom annular surface with the upward movement of valve clack, and step extrudes sealing element, and makes sealing element produce radial deformation to seal the gap between valve clack and spring cavity bottom. The structure of safety valve is simplified, and the production cost is reduced, and simultaneously, can realize the sealing according to the motion of valve clack, and the sealing effect is good and reliable, and effectively avoid the sealing failure problem caused by bellows damage, therefore, the structural mode is applicable to the application scene of lower cost and lower sealing requirement.

Description

Technical Field

[0001] This utility model relates to the field of safety valve technology, specifically a safety valve with a stepped valve disc seal. Background Technology

[0002] Safety valves, as important overpressure protection devices, are widely used in various pressure vessels and pipeline systems. Their core function is to quickly open and discharge the medium when the system pressure exceeds a preset safety value, and to promptly close and reseal the valve after the pressure returns to normal. In existing technologies, a bellows-balanced structure is often used to balance back pressure and protect internal components such as springs from the influence of the medium. For example, Chinese patent document CN202392206U discloses a "bellows-balanced safety valve." This safety valve uses a bellows as a key sealing element to completely separate the valve chamber from the upper spring chamber. The upper end of the bellows is fixed, and the lower end is connected to the valve disc. This balances the force of back pressure on the valve disc and ensures that components such as the spring in the spring chamber do not come into contact with the process medium, thereby avoiding interference from corrosion, crystallization, or solid particles in the medium on the spring's operating performance. However, this structure has revealed some shortcomings in practical applications.

[0003] First, the cost is high. As a precision metal component, the bellows itself has high material and manufacturing costs, directly increasing the overall cost of the safety valve. Second, there is a fatigue life limitation. During the opening and closing process, the bellows needs to withstand repeated compression and tension cycles, making it highly susceptible to damage and rupture due to material fatigue. Once the bellows fails, not only will it lose its sealing and balancing functions, but it may also lead to media leakage and safety accidents. Third, manufacturing and maintenance are complex. The installation and welding processes for the bellows require high precision, increasing manufacturing complexity. Furthermore, maintenance and replacement are more cumbersome and costly. Utility Model Content

[0004] The purpose of this utility model is to overcome the defects of the prior art and provide a new type of safety valve with a stepped valve disc seal, which can avoid the use of bellows and at the same time achieve an effective and reliable seal between the valve cavity and the spring cavity.

[0005] The technical solution of this utility model includes a valve body, a spring cavity and a valve cavity disposed within the valve body, and a valve disc movably disposed at the bottom opening of the spring cavity. A spring is connected to the upper end of the valve disc, and an annular step is provided on the outer periphery of the valve disc. A sealing element is sleeved on the step. A bottom annular surface is formed at the bottom of the spring cavity. When the safety valve is opened and the valve disc moves upward, the sealing element rises accordingly and contacts the bottom annular surface. The step squeezes the sealing element, causing the sealing element to undergo radial deformation to seal the gap between the valve disc and the bottom of the spring cavity.

[0006] By adopting the above technical solution, an annular step is set on the outer periphery of the valve disc and a sealing element is fitted on it, eliminating the expensive and easily damaged bellows structure, simplifying the construction of the safety valve, and reducing production costs. At the same time, when the valve disc moves upward to open the safety valve, the step squeezes the sealing element, causing it to undergo radial deformation to seal the gap between the valve disc and the bottom of the spring cavity. This sealing method can automatically achieve sealing according to the movement of the valve disc, with good and reliable sealing effect, effectively avoiding the sealing failure problem caused by bellows damage. Therefore, this structural method is suitable for application scenarios with low cost and low sealing requirements.

[0007] In one possible design, a bottom groove is provided on the bottom ring surface, and when the seal is compressed, part of it is embedded in the bottom groove.

[0008] With the above design, the bottom groove provides a preset deformation space for the compressed seal, which allows the seal to generate more fully controllable radial deformation. This not only enhances the tightness and reliability of the seal, but also avoids premature damage or local wear of the seal due to irregular compression, thereby further improving the durability of the seal and the stability of the sealing effect.

[0009] In one possible design, the bottom groove is a chamfered groove, and the seal is an O-ring that, when embedded in the bottom groove, contacts the outer circumferential surface of the valve disc step radially inward.

[0010] With the above design, the chamfered groove has an excellent guiding and accommodating effect on the O-ring, which can guide the O-ring to deform evenly inward and downward to form a tighter radial seal. This solution reduces the processing difficulty and production cost while ensuring excellent sealing performance, and has high practicality and economy.

[0011] In one possible design, the bottom groove is a right-angled groove, and the bottom of the right-angled groove has a first annular protrusion along the valve disc axis; the sealing element is an O-ring, and its axial top side has a first annular groove that matches the first annular protrusion; when the sealing element is compressed, the first annular protrusion is embedded in the first annular groove.

[0012] With the above design, the first ring protrusion and the first ring groove form a nested sealing structure, which expands the sealing path and enhances the tightness of the sealing interface. It can effectively prevent the medium from leaking along the axial gap. The first ring protrusion can also limit the sealing element and prevent it from being squeezed too much into the gap under high pressure, thereby improving the stability of the sealing element under high pressure conditions.

[0013] In one possible design, the axial top surface of the seal has an annular protrusion; the bottom groove is a right-angle groove, and a U-shaped sealing ring is fixedly installed in the right-angle groove. The bottom surface of the U-shaped sealing ring has a U-shaped groove that matches the annular protrusion.

[0014] By adopting the above design, a more flexible and adaptive seal is achieved by utilizing the line contact or surface contact between the ring protrusion and the U-groove of the U-shaped sealing ring. The inherent elasticity of the U-shaped sealing ring allows it to better compensate for machining and assembly errors, and can form an effective seal even under low pressure. Furthermore, the cooperation between the ring protrusion and the U-groove provides multiple sealing barriers, which improves the sealing effect and adaptability to different working conditions, making it particularly suitable for working scenarios with high sealing requirements.

[0015] In one possible design, the inner ring surface of the seal is provided with a second ring groove, and the step of the valve disc or the outer peripheral wall is provided with a second ring protrusion that matches the second ring groove, and the second ring protrusion is placed in the second ring groove.

[0016] The above design achieves axial limiting of the seal, effectively preventing relative movement of the seal during valve disc operation, ensuring the accuracy of the seal's working position, and thus guaranteeing the stability and consistency of dynamic sealing. At the same time, the structure itself also constitutes an additional static sealing barrier, further preventing the possibility of media leakage between the valve disc and the seal.

[0017] In one possible design, the cross-section of the first annular groove is V-shaped or semi-circular.

[0018] With the above design, the V-shaped cross-section can provide a sharper contact edge, generating greater contact stress under the same clamping force, thus forming a more airtight sealing line; the semi-circular cross-section can make the stress distribution more uniform, reduce the local shear stress on the sealing ring, and help extend the service life of the O-ring.

[0019] In one possible design, the cross-section of the second annular groove is V-shaped or semi-circular.

[0020] With the above design, the V-shaped groove and the second ring protrusion cooperate to produce a stronger biting and limiting effect, preventing the seal from loosening; the semi-circular groove provides better tolerance and stress dispersion ability, making the seal easier to install on the valve disc and more stable in operation.

[0021] In one possible design, the wall of the right-angle groove is provided with a limiting protrusion, which abuts against the bottom surface of the U-shaped sealing ring.

[0022] With the above design, the limiting protrusions provide clear positioning and reliable fixation for the installation of the U-shaped sealing ring in the right-angle groove. This prevents the U-shaped sealing ring from falling off or shifting from the groove during transportation, vibration, or long-term use, ensuring the accuracy of the sealing assembly and the stability of long-term operation, and simplifying the installation and maintenance process. Attached Figure Description

[0023] Figure 1This is a cross-sectional view of a specific embodiment of the present utility model; Figure 2 This utility model Figure 1 A magnified view of a section at point A in the middle; Figure 3 This is a schematic diagram of the structure of a specific embodiment two of the present utility model; Figure 4 This utility model Figure 3 A magnified view of a section at point B in the middle; Figure 5 This is a partial enlarged view of a specific embodiment three of this utility model; Among them, 1. Valve body; 2. Spring cavity; 3. Valve cavity; 4. Valve disc; 5. Step; 6. Seal; 7. Bottom ring surface; 8. Chamfered groove; 9. Right angle groove; 10. First ring protrusion; 11. First ring groove; 12. Second ring groove; 13. Second ring protrusion; 14. Ring protrusion; 15. U-shaped sealing ring; 16. U-shaped groove; 17. Limiting protrusion. Detailed Implementation

[0024] like Figures 1 to 5 The safety valve shown is a stepped valve disc seal. Its basic working principle is as follows: a step 5 is set on the outer periphery of the valve disc 4 and a sealing element 6 is installed. When the safety valve is opened and the valve disc 4 rises, the sealing element 6 rises accordingly and comes into contact with a specific structure at the bottom of the spring cavity 2 and is squeezed, producing radial deformation, thereby dynamically sealing the annular gap between the valve disc and the spring cavity. Example 1

[0025] like Figure 1 , Figure 2 As shown, this embodiment includes a valve body 1, within which a spring cavity 2 and a valve cavity 3 are formed. A valve disc 4 is movably positioned at the bottom opening of the spring cavity 2 via a guide structure, and a spring providing closing force is connected to its upper part. An annular step 5 is machined on the outer periphery of the valve disc 4, and a sealing element 6 is fitted onto the step 5. In this embodiment, the sealing element 6 is preferably a universal O-ring seal; a bottom annular surface 7 is formed at the bottom of the spring cavity 2, and an annular bottom groove, specifically a chamfered groove 8, is formed on this bottom annular surface 7.

[0026] When the system pressure is normal, valve disc 4 closes under the action of the spring, and seal 6 separates from bottom annular surface 7 and chamfered groove 8. When the system overpressures and the safety valve opens, valve disc 4 moves upward under pressure, causing seal 6 on its step 5 to rise together. After seal 6 contacts bottom annular surface 7, valve disc 4 continues to rise, and step 5 presses upward against seal 6, forcing seal 6 to deform. Part of the deformed seal 6 embeds into chamfered groove 8 and, guided by the inclined surface of chamfered groove 8, fits radially inward tightly against the outer circumferential surface of step 5 of valve disc 4, thereby effectively sealing the annular gap between valve disc 4 and the bottom of spring cavity 2, preventing the medium from entering the spring cavity. Example 2

[0027] like Figure 3 , Figure 4 As shown, this embodiment is an optimization based on Embodiment 1. Its basic structure is the same as that of Embodiment 1, including valve body 1, spring cavity 2, valve cavity 3, valve disc 4, and valve disc step 5.

[0028] The difference in this embodiment is that the bottom groove on the bottom ring surface 7 is a right-angled groove 9. At the bottom of the right-angled groove 9 (i.e., the bottom along the axial direction of the valve disc), a first annular protrusion 10 with a semi-circular cross-section is protruded along the circumferential direction. Correspondingly, the sealing element 6 fitted on the valve disc step 5 is a specially made O-ring. A first annular groove 11 is formed on the axial top side of the O-ring (i.e., the side opposite to the first annular protrusion 10). The cross-section of the first annular groove 11 is preferably V-shaped or semi-circular, used to mate with the first annular protrusion 10. Of course, since the cross-section of the first annular protrusion 10 and the first annular groove 11 are adapted, their shapes are the same or similar.

[0029] When the safety valve opens and the seal 6 is compressed, the first annular protrusion 10 will embed into and fill the first annular groove 11. This interlocking of the protrusion and groove forms a multi-bend sealing barrier, which enhances the tightness of the seal and effectively prevents the medium from leaking along the axial direction.

[0030] To further optimize the design, a second annular groove 12 is provided on the inner surface of the O-ring seal. Simultaneously, a second annular protrusion 13, adapted to the second annular groove 12, is machined at the step 5 (or on the outer peripheral wall) of the valve disc 4. The cross-section of this second annular protrusion 13 is preferably semi-circular. The second annular protrusion 13 is inserted into the second annular groove 12. This structure achieves axial positioning of the seal 6, effectively preventing displacement of the seal 6 during operation and ensuring sealing stability. It also constitutes an additional sealing line. Example 3

[0031] like Figure 5As shown, this embodiment provides another optimized solution. Its basic structure also includes a valve body 1, a spring cavity 2, a valve cavity 3, a valve disc 4, and a valve disc step 5.

[0032] In this embodiment, the sealing member 6, which is fitted onto the valve disc step 5, has an annular protrusion 14 formed on its axial top surface, and a right-angle groove 9 is formed on its bottom annular surface 7. Unlike the previous embodiment, this embodiment has a U-shaped sealing ring 15 fixedly installed in the right-angle groove 9. The bottom surface of the U-shaped sealing ring 15 (i.e., the surface opposite to the annular protrusion 14) has a U-shaped groove 16 that matches the shape of the annular protrusion 14.

[0033] When the safety valve opens, the valve disc 4 drives the sealing element 6 to rise. The annular protrusion 14 on the top of the sealing element 6 will embed into the U-shaped groove 16 of the U-shaped sealing ring 15, forming a tight line contact or surface contact seal. The excellent elasticity of the U-shaped sealing ring 15 allows it to better adapt to the annular protrusion 14, forming multiple sealing lips, resulting in a better sealing effect, especially suitable for working conditions with pressure fluctuations.

[0034] Similarly, the sealing element 6 in this embodiment can also adopt the same limiting structure as in Embodiment 2. That is, a second annular groove 12 is formed on the inner annular surface of the sealing element 6, the cross-section of which can be V-shaped or semi-circular, and a corresponding second annular protrusion 13 is provided on the valve disc step 5, and the sealing element 6 is fixed by the cooperation of the two.

[0035] Furthermore, to ensure the stability of the U-shaped sealing ring 15 within the right-angle groove 9 and to prevent it from falling off, several independent limiting protrusions 17 or annular limiting protrusions 17 are machined or machined on the groove wall of the right-angle groove 9. During installation, the U-shaped sealing ring 15 is pressed into the right-angle groove 9 so that its bottom surface abuts against these limiting protrusions 17, thereby being reliably limited within the groove.

Claims

1. A safety valve with a disc step seal, comprising a valve body (1), a spring cavity (2) and a valve cavity (3) arranged in the valve body (1), and a valve disc (4) movably arranged at the bottom opening of the spring cavity (2), and a spring connected to the upper end of the valve disc (4), characterized in that: The outer periphery of the valve disc (4) is provided with an annular step (5), and a sealing element (6) is sleeved on the step (5); the bottom of the spring cavity (2) is formed with a bottom annular surface (7). When the safety valve is opened, the valve disc (4) moves upward, and the seal (6) rises accordingly and contacts the bottom ring surface (7). The step (5) squeezes the seal (6), causing the seal (6) to undergo radial deformation to seal the gap between the valve disc (4) and the bottom of the spring cavity (2).

2. The safety valve with stepped valve disc seal according to claim 1, characterized in that: A bottom groove is provided at the bottom ring surface (7), and when the seal (6) is squeezed, part of it is embedded in the bottom groove.

3. The safety valve with stepped valve disc seal according to claim 2, characterized in that: The bottom groove is a chamfered groove (8), and the sealing element (6) is an O-ring. When the O-ring is embedded in the bottom groove, it contacts the outer circumferential surface of the step (5) of the valve disc (4) radially inward.

4. The safety valve with stepped valve disc seal according to claim 2, characterized in that: The bottom groove is a right-angle groove (9), and the bottom of the right-angle groove (9) is provided with a first annular protrusion (10) along the axial direction of the valve disc (4); the sealing element (6) is an O-ring, and a first annular groove (11) adapted to the first annular protrusion (10) is provided on its axial top side; when the sealing element (6) is squeezed, the first annular protrusion (10) is embedded in the first annular groove (11).

5. The safety valve with stepped valve disc seal according to claim 2, characterized in that: The sealing element (6) has an annular protrusion (14) on its axial top surface; the bottom groove is a right-angle groove (9), and a U-shaped sealing ring (15) is fixedly installed in the right-angle groove (9). The bottom surface of the U-shaped sealing ring (15) has a U-shaped groove (16) that matches the annular protrusion (14).

6. The safety valve with stepped valve disc seal according to claim 4 or 5, characterized in that: The inner ring surface of the sealing element (6) is provided with a second ring groove (12), and the step (5) of the valve disc (4) or the outer peripheral wall is provided with a second ring protrusion (13) that matches the second ring groove (12). The second ring protrusion (13) is placed in the second ring groove (12).

7. The safety valve with stepped valve disc seal according to claim 4, characterized in that: The cross-section of the first annular groove (11) is V-shaped or semi-circular.

8. The safety valve with stepped valve disc seal according to claim 6, characterized in that: The cross-section of the second annular groove (12) is V-shaped or semi-circular.

9. The safety valve with stepped valve disc seal according to claim 5, characterized in that: The right-angle groove (9) has a limiting protrusion (17) on its groove wall, and the limiting protrusion (17) abuts against the bottom surface of the U-shaped sealing ring (15).

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