Valve with spring

Abstract

The invention relates to a valve (17) comprising: a closing member; a shaft (101) connected to the closure member for adjusting the position of the closure member, and having an end (102) protruding to the outside of the valve via a packing cavity (18). The valve (17) further comprises a valve packing (103) arranged in the packing cavity (18) to surround the shaft (101), and a spring (1) disposed in the packing cavity (18) to contact the valve packing (103). In order to provide improved sealing performance to a valve packing (103), a spring (1) comprises: an upper support surface (2); a lower support surface (3); and at least two segments (4) arranged between the upper support surface (2) and the lower support surface (3) wherein at least one of the segments (4) comprises a spring unit (5).

Description

Technical Field

[0001] The invention relates to a valve with a spring. Background Art

[0002] With regard to industrial piping systems, significant fluid pressures are often encountered and need to be contained within the system. These conditions also place high demands on the valves used in conjunction with these piping systems, which must withstand the same pressure conditions and minimize fugitive emissions. The fluctuating temperatures associated with many industrial processes provide an additional challenge, where temperature fluctuations can be on the order of hundreds of degrees Celsius over a relatively short period of time. In recent years, increasingly stringent industry specifications have been set for acceptable fugitive emission rates for gases released by industrial valves, further increasing the requirements for the tightness of the seals between valve components and between the valve and the surrounding system. Most fugitive emissions in piping systems are typically caused by leaks at the rotating shaft or sliding rod of the valve.

[0003] Conventional shaft seal designs designed to maintain a good seal despite thermal cycling, packing loosening, wear, or extrusion use live-loaded packing. In live-loaded packing, the packing rings are compressed to high pressures within the packing ring cavity, typically on the order of tens of megapascals, by the force applied by studs (typically through a gland (follower)). Pre-tensioned Belleville spring washers between the gland and the stud fasteners provide considerable force to maintain the desired packing compression for a period of time. However, the sealing performance achieved in this manner is often less than ideal due to the uneven force distribution along the length of the packing caused by friction between the packing elements. Due to the gradual change in force distribution and the time-dependent behavior of the packing material, sealing performance can also degrade over time. This, combined with the limited compression length reserve provided by the spring assembly, can lead to performance degradation over time or under varying temperature conditions. It is also known in the art to place springs at the base of the packing to provide a more even force distribution along the length of the packing. However, conventional springs do not have sufficient performance to withstand the high compression applied by the studs and provide sufficient spring force with minimal hysteresis within a relatively small size (height versus deflection / spring force). For example, a valve sealing device using such a spring system is known from CN 218094596U. Summary of the Invention

[0004] An object of the present invention is to address the above-mentioned disadvantages and to provide a solution with improved sealing properties. This object is achieved by a valve according to independent claim 1 .

[0005] A structure capable of achieving tight sealing and a low discharge rate can be obtained by providing a valve with a spring including upper and lower support surfaces and a segment disposed between the upper and lower support surfaces, the segment including a spring cell.

[0006] Preferred embodiments of the invention are disclosed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Hereinafter, the present invention will be described in more detail by way of examples and with reference to the accompanying drawings, in which:

[0008] Figure 1 shows a side view of a segment according to a first embodiment of a spring,

[0009] Figure 2 A second embodiment of the spring is shown, seen diagonally from above,

[0010] Figure 3 shows a side view of a third embodiment of a spring,

[0011] Figure 4 shows a side view of a fourth embodiment of a spring,

[0012] Figure 5 shows a side view of a fifth embodiment of a spring,

[0013] Figure 6 shows a side view of a segment according to a sixth embodiment of a spring,

[0014] Figure 7 Shows the settings according to Figures 1 to 6 a partial cross-section of a valve of any one of the springs, and

[0015] Figure 8 Shown diagonally from the side Figure 7 The valve as a whole. DETAILED DESCRIPTION

[0016] Figure 1 A side view of a segment 4 according to a first embodiment of a spring 1 is shown. The spring 1 according to said first embodiment comprises an upper support surface 2 and a lower support surface 3, and a spring according to Figure 1 In this document, a segment 4 is defined as a repeating structural unit that is continuously arranged to form a uniform structure between the support surfaces 2 and 3. To further illustrate this concept, Figure 6, which corresponds to the sixth embodiment of the spring 1. In a preferred arrangement of the spring structure, the spring 1 is provided with at least three segments 4, more preferably 8 to 10 segments 4. For example, the number of segments 4 can be adjusted based on the diameter of the spring 1 or the desired stiffness. In some embodiments, the segments 4 can also be arranged to fill only a portion of the volume between the support surfaces 2, 3, leaving empty space for structure between at least some of the adjacent segments 4.

[0017] Figure 2 A second embodiment of a spring 1 is shown, seen in its entirety from above diagonally. The spring 1 according to this example comprises a spring having a Figure 1 Segment 4 of the same main structure disclosed, where additional elements are added to the structure for further advanced functionality. Figure 2 In the example of FIG, the upper support surface 2 and the lower support surface 3 are arranged parallel to each other and are formed on two annular structures 19 at the respective upper and lower ends of the spring 1 and define the outer boundaries of the spring at said ends. In this document, the terms "upper" and "lower" refer to the positions of the spring 1 when viewed in its installed position. Figure 2 As shown, the segment 4 between the upper support surface 2 and the lower support surface 3 includes a spring unit 5 having an upper segment 6 connected to the upper support surface 2 and an opposite lower segment 7 connected to the lower support surface 3. In different embodiments of the spring 1, the spring unit 5 is provided to at least one of the segments 4, while some of the segments 4 can also be provided to the spring without the spring unit 5.

[0018] exist Figure 2 In the example of FIG. 5 , both the upper section 6 and the lower section 7 of the spring unit 5 comprise two opposing arcuate segments 14, wherein each arcuate segment 14 is connected at one end to a corresponding arcuate segment of the opposing unit segment and at the other end to the respective upper and lower support surfaces 2, 3. At the connection points between the arcuate segments 14 of the opposing unit segments, an angle 20 is formed. In the example described, the connection of the spring unit 5 to the support surfaces 2, 3 is made via annular ring formations 19 at the respective upper and lower ends of the spring 1.

[0019] As a result of the arrangement described, the arcuate segments 14 together form a structure that can elastically adapt to the compression of the spring unit 5 in the upward and downward directions by bending and reorienting the arcuate segments 14. In this way, the spring unit 5 forms the elastic structure of the spring 1, so that the spring 1 can be elastically compressed in a direction perpendicular to the upper support surface 2 and the lower support surface 3, in other words, so that the distance between the support surfaces 2, 3 is reduced. In other embodiments of the spring 1, the structure of the spring unit 5 can also be arranged differently based on, for example, the expected loading conditions or the required stiffness of the spring 1 in the current application. For example, the arcuate segments 14 can also be shaped to define a circular shape of the spring unit 5, which is different from the circular shape of the spring unit 5. Figure 2 In contrast to the angular shape shown in the example of . In some embodiments of the spring 1 , the arcuate segment 14 can also be provided as a substantially straight portion.

[0020] Figure 2 The spring 1 in the example of FIG1 is arranged in the shape of a ring, in other words, such that it includes a channel 8 extending from the upper support surface 2 to the lower support surface 3 along the middle axis 9 of the spring 1. In the described example, the four interconnected arcuate segments 14 included in the spring unit 5 are configured to form a closed loop that opens towards and away from the middle axis 9, in other words, such that an opening is formed through the spring unit 5 that extends from the channel 8 to the outer periphery of the spring 1. In the described arrangement, compression of the spring 1 causes the arcuate segments 14 to bend and reorient, such that the width of the spring units 5 (in other words, their extension in the tangential direction of the spring 1) increases, while at the same time their height (in other words, their extension towards the upper support surface 2 and the lower support surface 3) decreases.

[0021] In contrast, in a possible rotational arrangement in which the orientation of the spring units 5 causes them to extend under compression in a radial direction of the spring 1 , the compression of the spring 1 may be limited by the space available in said radial direction, i.e. the distance between the channel 8 and the outer periphery of the spring 1 . Figure 2 In the example shown, the spring 1 is a cylindrical spring whose outer periphery across the length of the spring 1 follows the periphery of the two circular ring formations 19 at the upper and lower ends of the spring 1. In other embodiments of the spring 1, the outer periphery can also be formed so that the diameter or cross-sectional shape of the spring varies over the length of the spring to suit the size or structural requirements set by any particular use case.

[0022] Figure 3 A third embodiment of the spring 1 is shown, which shares Figure 2 Most of the structural features shown in the examples. Figure 2 and Figure 3In the example shown, the spring unit 5 is connected to the upper support surface 2 and the lower support surface 3 via spring arms 11. More specifically, in the example shown, a spring arm 11 extends between the upper section 6 of the spring unit 5 and the upper support surface 2, and another spring arm 11 extends between the lower section 7 of the spring unit 5 and the lower support surface 3. By adding the disclosed spring arms 11, an additional elastically compressible element is provided for the spring 1. In other embodiments of the spring 1, the spring arms 11 may be provided only to some of the spring units 5, or they may be provided, for example, only to the upper section 6 or the lower section 7 of the spring unit 5.

[0023] exist Figure 2 and Figure 3 In the example shown, each spring arm 11 is shaped as an arcuate portion 12 that curves around the spring unit 5 and connects to the upper support surface 2 or the lower support surface 3 at both ends. In other words, the spring arms 11 are arranged to partially surround the spring unit 5 at the upper and lower sections 6 and 7, while defining separation gaps 22 between the spring unit 5 and the upper and lower support surfaces 2 and 3, respectively, directly above and below the spring unit 5. This arrangement provides an additional degree of resilience to the spring 1, wherein compression of the spring 1 causes the spring arms 11 to deflect by bending, thereby allowing the spring unit 5 to move closer to the respective support surface 2 or 3. However, in some embodiments of the spring 1, the spring arms 11 may also be provided as sections extending upward and downward, respectively, between the spring unit 5 and the support surfaces 2 or 3, in other words, such that the spring arms 11 have a substantially vertical orientation. In this case, the spring arms 11 can provide resilience by, for example, deflecting laterally under compression.

[0024] Figure 4 A fourth embodiment of a spring 1 is shown, seen directly from the side. Figure 4 The cylindrical spring 1 shown in the example of FIG. 1 shares most of the structural features of the second and third embodiments. In this example, the spring 1 further comprises a compression limiter 10 extending from the lower support surface 3 towards the upper support surface 2 over a portion of the distance between the support surfaces 2, 3. More precisely, the compression limiters 10, which are formed as elongated rods in the example, extend perpendicularly from the lower support surface 3 so that a gap 21 is formed between the free end of each compression limiter 10 and the upper annular structure 19 comprising the upper support surface 2. In other embodiments of the spring 1, the number, shape and position of the compression limiters 10 can freely deviate from Figure 4 , such that the compression limiter 10 may also extend from the upper support surface 2 towards the lower support surface 3 , mirroring the arrangement shown.

[0025] The disclosed arrangement of compression limiter 10 allows adjustment of the degree of compression provided by spring 1—that is, the maximum reduction in the distance between upper support surface 2 and lower support surface 3. In other words, by compressing spring 1, gap 21 between compression limiter 10 and upper or lower annular structure 19 decreases until contact is established between compression limiter 10 and annular structure 19. At this point, further compression of spring 1 causes compression limiter 10 to contribute to the load acting on spring 1, effectively inhibiting further compression. Thus, the load-bearing behavior of spring 1—in other words, its spring curve—can be further adjusted by the incorporation and sizing of compression limiter 10. The maximum amount of compression available to spring 1 is referred to as its compression length reserve.

[0026] In addition, Figure 3 and Figure 4 In the example of FIG, the arcuate portion 12 continues at both ends into curved portions 13 that turn toward the upper support surface 2 and the lower support surface 3, respectively. Figure 4 In the example of , the bow 12 at each spring arm 11 is folded around the curve 13 at its two ends, thereby providing an additional layer of elastically curved structure between the spring unit 5 and the support surface 2, 3. Figure 3 In the examples of , the arrangement provides a rigid structural point to the segment 4, working in conjunction with the corresponding position of the adjacent segment 4. In both examples, a secondary segment 23 of the spring arm 11 is located between the curved portion 13 and the support surface 2, 3, said secondary segment having a similar orientation and structure to the arched portion 12 and connected to the respective support surface 2, 3. Figure 3 In the example of FIG. 1 , adjacent segments 4 are interconnected at the curved portion 13, while Figure 4 In the example shown, the spring arms 11 extend along their entire length as independent structures.

[0027] Figure 3 The interconnected structure shown in FIG1 enables the spring arms 11 to simultaneously serve as compression limiters 10, in which case each compression limiter 10 is formed up to the location of the curve 13 of each spring arm 11 and comprises the adjoining spring arm sections of two adjacent segments 4. In the arrangement described, two compression limiters 10 face each other at the interface between each two adjacent segments 4, the spacing between the two compression limiters 10 defining the compression length reserve of the spring 1.

[0028] exist Figures 2 to 4 In the example of FIG, the spring unit 5 at each segment 4 is connected to the spring arm 11 at the middle section of the arch 12. By said arrangement, a symmetrical bending pattern of the segment 4 along the tangential direction of the spring 1 is ensured to avoid any asymmetrical deflection or buckling of the spring 1 during compression. Figures 2 to 5The other parts of the spring structure of any example are also arranged in a symmetrical shape along the tangential direction of the spring.

[0029] exist Figure 4 In the example of FIG. 1 , the lower support surface 3 is formed by a plurality of sectors 15 separated by gaps 16, wherein each sector 15 is connected to two adjacent segments 4. This arrangement allows further adjustment of the stiffness of the spring 1, i.e., its spring curve, as well as the load transfer between the structural elements of the spring 1. In different embodiments of the spring 1, either the upper support surface 2 or the lower support surface 3 can be formed by separate sectors 15 connected to at least one of the segments 4.

[0030] Figure 7 A partial cross section of a valve 17 is shown which is provided with a sealing device comprising a spring 1. In this example, the spring 1 is a cylindrical spring 1 of a valve packing and is arranged according to e.g. Figures 2 to 5 Any of the springs 1 in the examples may be used in conjunction with the arrangement shown. To better illustrate the types of applications in which the sealing device may be used, Figure 8 The whole is shown in Figure 7 The valve. Figure 7 and Figure 8 In the present invention, the valve 17 has been shown schematically to highlight the main components of the construction, and the valve 17 may have a different structure from the examples shown in other embodiments of the valve.

[0031] As in Figure 7 and Figure 8 As seen in the example of FIG. 1 , the valve 17 includes a closure member 100, a shaft 101 connected to the closure member for adjusting the position of the closure member and having an end 102 protruding to the outside of the valve via a packing cavity 18. The valve 17 also includes a valve packing 103 arranged in the packing cavity 18 to surround the shaft 101, and a spring 1 provided in the packing cavity 18 to contact the valve packing 103, which may be, for example, a spring according to Figures 2 to 5 For example, the valve packing 103 may include a packing ring used in a conventional valve packing device and provide a sealing interface for the sealing device. Figure 7In the example shown, an anti-extrusion ring 106 is also provided in the packing cavity 18 as part of the valve packing 103. The anti-extrusion ring 106 provides an additional layer of protection to prevent the valve packing 103 from being unbalancedly squeezed or protruded within the packing cavity 18. The packing cavity 18 is enclosed within the valve body 105, and the end 102 of the shaft 101 protrudes to the outside of the valve through the valve body 105. A live-load system including a conventional coil spring assembly 104 is also provided on the outside of the valve body 105. In this example, the live-load system serves as a supplement to the spring 1, thereby providing a force from above to compress the valve packing 103 through the gland 107.

[0032] By using a valve 17 including a packing cavity 18 and placing a spring 1 including an upper support surface 2 and a lower support surface 3 into the packing cavity 18, it is possible to set the valve 17 according to Figure 7 The spring 1 can be provided together with the valve packing 103. When retrofitting the spring 1 to an existing valve packing arrangement of conventional structure, some of the plurality of packing rings can be removed from the packing cavity 18 to accommodate the spring 1. Some or all of the previously provided structural elements, such as the conventional coil spring group 104 of the dynamic load system, can also be retained and used in conjunction with the spring 1.

[0033] The disclosed method is continued by applying a force to the spring 1 in the longitudinal direction of the packing cavity 18 in order to reduce the distance between the upper support surface 2 and the lower support surface 3. By applying a compressive force to the spring 1 as described above, a compression length reserve is provided for the valve seal, which allows the seal to accommodate compression losses that would otherwise occur. Such compression losses typically occur due to, for example, wear, temperature, and time-related relaxation of structural elements of the seal, ultimately leading to increased drainage of the valve connection.

[0034] Due to the structural features of the disclosed spring 1, a spring can be provided with a combination of high stiffness and a large compressed length relative to the length of the spring 1. For example, the spring 1 can be configured such that, when the disclosed method is applied to a spring 1 having an inner diameter of approximately 45 mm, an outer diameter of approximately 60 mm, and a free length of approximately 20 mm, the length of the spring (in other words, the distance between the upper support surface 2 and the lower support surface 3) can be reduced by approximately 2 to 3 mm by applying a compressive force that generates a contact pressure of approximately 50 MPa on the packing ring. Consequently, this reduction in the distance between the support surfaces 2 and 3 corresponds to a relatively large percentage of the uncompressed distance between the support surfaces 2 and 3, which represents the free length of the spring 1. In this way, a relative compression value of approximately 15% to 20% of the free length of the spring can be achieved. In contrast, conventional sealing solutions utilizing coil springs having a diameter similar to the disclosed method may require a spring with a free length up to twice as large to achieve a compressed length similar to the disclosed method.

[0035] Figures 2 to 5 The spring 1 of the example is provided as a unitary structure, in other words, each of the disclosed structural elements is seamlessly connected to the spring structure. Such a structure can be provided by utilizing, for example, an additive manufacturing method or a laser cutting method, wherein the structural elements are provided by cutting a preform that defines the outer dimensions of the spring 1. However, in some embodiments of the spring 1, the spring 1 can also be provided as a multi-part structure. For example, this can be achieved by providing the segments 4 as separate structural units or as a cluster between the annular structures 19 at the upper and lower ends of the spring 1, which are also provided as separate structural units. In this arrangement, conventional rings or washers can also be used at the upper and lower ends of the spring 1 to combine the segments 4.

[0036] In such Figures 2 to 5 In the overall structure shown, any potential friction caused by relative movement between structural elements at their contact interfaces during compression is avoided, thereby allowing for improved force distribution over the length of spring 1 and minimal or no hysteresis, for example, in the event of thermal cycling or (re)adjustment of dynamically loaded sealing systems. This, in turn, has a positive impact on the sealing performance of spring 1, as the compressive force applied to the spring is more effectively transmitted to the sealing interface of the sealing structure. The spring 1 according to the present invention achieves similar benefits compared to conventional sealing solutions including, for example, coil springs, where the elastic deflection of the coil spring during compression inevitably leads to relative movement between the coil spring and the reacting structural element at their contact interfaces, thereby generating friction and hysteresis in their force output and spring curve. In this context, hysteresis refers to the asymmetry of the spring curve, as observed when measuring the spring's response to loading and unloading. In this context, unloading can be intentional unloading of the compressive force or unintentional unloading due to, for example, wear of the sealing components.

[0037] It should be understood that the above description and the accompanying drawings are only intended to illustrate the present invention. It will be apparent to those skilled in the art that changes and modifications may be made to the present invention without departing from the scope of the present invention. Figures 1 to 8 The relative dimensions of the individual sections of the spring 1 and the accompanying structures shown in FIG can deviate from the illustration.

Claims

1. A valve (17), comprising: a closing member (100), a shaft (101) connected to the closure member (100) for adjusting the position of the closure member and having an end (102) protruding to the outside of the valve via a packing cavity (18), a valve packing (103) disposed in the packing cavity (18) to surround the shaft (101), and A spring (1) is arranged in the packing cavity (18) to contact the valve packing (103), wherein the spring (1) comprises: upper support surface (2), a lower support surface (3), and At least two segments (4) are arranged between the upper support surface (2) and the lower support surface (3), wherein At least one of the segments (4) comprises a spring unit (5) having an upper segment (6) connected to the upper support surface (2) and an opposite lower segment (7) connected to the lower support surface (3), the upper segment (6) and the lower segment (7) comprising two opposite arcuate segments (14).

2. The valve (17) according to claim 1, characterized in that The spring (1) further includes at least one compression limiter (10) extending from one of the upper support surface (2) and the lower support surface (3) toward the other of the upper support surface (2) and the lower support surface (3) by a portion of the distance between the upper support surface (2) and the lower support surface (3).

3. The valve (17) according to claim 1 or 2, characterized in that At least one of the spring units (5) is connected to at least one of the upper support surface (2) and the lower support surface (3) via a spring arm (11).

4. The valve (17) according to claim 3, characterized in that at least one spring arm (11) extending between the upper section (6) of the spring unit (5) and the upper support surface (2), and At least one spring arm (11) extends between the lower section (7) of the spring unit (5) and the lower support surface (3).

5. The valve (17) according to claim 3 or 4, characterized in that At least one of the spring arms (11) is shaped as an arcuate portion (12) which is bent around the unit (5) and connected at both ends to the upper support surface (2) or the lower support surface (3).

6. The valve (17) according to claim 5, characterized in that The arched portion (12) continues at both ends into curved portions (13) that turn toward the upper support surface (2) and the lower support surface (3), respectively.

7. The valve (17) according to claim 5 or 6, characterized in that The spring unit (5) at each of the segments (4) is connected to the at least one spring arm (11) at a middle section of the bow portion (12).

8. The valve (17) according to any one of claims 1 to 7, characterized in that The upper section (6) and the lower section (7) of the spring unit (5) both comprise two opposing arcuate segments (14), wherein each arcuate segment (14) is connected at one end to a corresponding arcuate segment of the opposing unit section and at the other end to the respective upper support surface (2) and the lower support surface (3).

9. The valve (17) according to any one of claims 1 to 8, characterized in that At least one of the upper support surface (2) and the lower support surface (3) is formed by a plurality of sectors (15) separated by gaps (16), wherein each sector (15) is connected to at least one of the segments (4).

10. The valve (17) according to any one of claims 1 to 9, characterized in that The spring unit (5) of the segments (4) comprises four interconnected segments (14) configured to form a closed loop that opens towards and away from the middle axis (9) of the spring (1).

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