Large-diameter high-temperature hard sealing control ball valve

Abstract

A large-diameter high-temperature hard sealing control ball valve, comprising a valve body and a valve cover, a ball body is arranged between the valve body and the valve cover, a valve rod is connected to the ball body, a recess is arranged at the bottom of the ball body, a support ball is arranged between the recess and the valve body, a disc spring and a support ball seat are further arranged between the support ball and the recess, the support ball, the support ball seat and the disc spring together form an elastic support assembly, the ball body forms a low-friction pair with the support ball and the support ball seat, and the elastic deformation capacity of the disc spring is combined to give the ball body self-adaptive adjustment freedom, which not only significantly reduces the eccentric load of the ball body on the valve seat, but also effectively compensates for the manufacturing tolerance, installation deviation and high-temperature thermal expansion difference, ensures that the ball body can be more accurately centered with the valve seat and uniformly attached, avoids the risk of abnormally increased operation torque or even valve jamming, and improves the sealing reliability and service life.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically to a large-diameter high-temperature hard-seal control ball valve. Background Technology

[0002] In high-temperature applications, floating ball valves typically have a lower risk of jamming due to their relatively simple structure and fewer moving parts. However, this structure has an inherent drawback: the ball relies solely on the downstream seat for support and positioning, resulting in extremely uneven load distribution on the seat, particularly with significant load concentration in the lower region. As the valve diameter increases, the ball's weight increases significantly, further exacerbating this uneven load distribution. This not only affects the uniform contact and long-term sealing performance of the sealing surface but also increases the risk of abnormal seat wear and even failure. Therefore, large-diameter high-temperature ball valves generally employ a fixed ball structure to overcome these drawbacks, but fixed ball valves are usually more complex and more expensive.

[0003] Traditional high-temperature ball valves widely use flexible graphite as the primary sealing material between the valve seat and body. However, flexible graphite is highly susceptible to oxidation and ablation in oxygen-containing high-temperature environments, leading to material weight loss, structural loosening, and a sharp decline in its sealing performance. This material failure is one of the key bottlenecks restricting the long-term reliable sealing of ball valves under harsh high-temperature conditions.

[0004] Ordinary ball valves typically open and close smoothly at room temperature. However, when used in high-temperature environments, the non-coordinated expansion of different material components (especially the ball and seat) due to differences in their coefficients of thermal expansion can significantly alter the mating clearance set at room temperature. This can easily lead to excessive compression or even seizing between the ball and seat. In this situation, the torque required to drive the valve stem will increase abnormally, far exceeding the rated output capacity of the turbine head or actuator, causing the valve to completely lose its opening and closing function and resulting in system interruption. Utility Model Content

[0005] To address the technical deficiencies of existing technologies, this utility model provides a large-diameter high-temperature hard-seal control ball valve.

[0006] The technical solution adopted in this utility model is: a large-diameter high-temperature hard-seal control ball valve, including a valve body and a valve cover. A ball is provided between the valve body and the valve cover, and a valve stem is connected to the ball. A groove is provided at the bottom of the ball, and a support ball is provided between the groove and the valve body. A disc spring and a support ball seat are also provided between the support ball and the groove. The support ball, the support ball seat, and the disc spring together constitute an elastic support assembly. The ball forms a low-friction pair with the support ball seat through the support ball, and the elastic deformation capability of the disc spring gives the ball an adaptive adjustment degree of freedom.

[0007] A valve seat is provided between the ball and the valve cover, and a valve seat pressure plate is provided on the valve seat. The valve seat pressure plate is fixed to the valve cover by bolts and provides pre-tightening force to the valve seat, so that the sealing surface between the valve seat and the valve cover can obtain a stable and reliable initial seal.

[0008] The valve seat pressure plate is provided with a groove corresponding to the position of the bolt. An anti-loosening washer is also provided between the bolt and the valve seat pressure plate. The anti-loosening washer is provided with three bends. When the anti-loosening washer is fitted onto the bolt, the bend at one end is inserted into the groove of the valve seat pressure plate to achieve axial limiting, while the remaining two bends are tightly attached to the head of the bolt to achieve circumferential limiting.

[0009] A hard alloy layer is also welded onto the sealing surfaces of the valve seat and the valve body.

[0010] A C-shaped sealing ring is also provided at the connection between the valve body and the valve cover.

[0011] The C-type sealing ring is made of a nickel-based alloy.

[0012] The beneficial effects of this utility model are as follows: This utility model provides a large-diameter high-temperature hard-seal control ball valve, including a valve body and a valve cover. A ball is provided between the valve body and the valve cover, and a valve stem is connected to the ball. The bottom of the ball is provided with a groove, and a support ball is provided between the groove and the valve body. A disc spring and a support ball seat are also provided between the support ball and the groove. The support ball, the support ball seat, and the disc spring together constitute an elastic support assembly. The ball forms a low-friction pair with the support ball seat through the support ball. Combined with the elastic deformation capability of the disc spring, the ball is given an adaptive adjustment degree of freedom. This not only significantly reduces the off-center load of the ball on the valve seat, but also effectively compensates for manufacturing tolerances, installation deviations, and differences in high-temperature thermal expansion. This ensures that the ball can be more accurately aligned with the center of the valve seat and fit evenly, avoiding the risk of abnormally increased operating torque or even valve jamming, and improving sealing reliability and service life. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model.

[0014] Figure 2 This is an enlarged structural schematic diagram of point C in this utility model.

[0015] Figure 3 This is an enlarged structural schematic diagram of point A in this utility model.

[0016] Figure 4 This is an enlarged structural schematic diagram of point B in this utility model.

[0017] Figure 5 This is a schematic diagram of the valve seat bolt anti-loosening structure of this utility model.

[0018] Figure 6 This is a schematic diagram of the anti-loosening gasket structure of this utility model.

[0019] Wherein: 1-valve body; 2-valve cover; 3-ball; 4-valve stem; 5-valve seat; 6-C-type sealing ring; 31-groove; 32-support ball; 33-disc spring; 34-support ball seat; 51-valve seat pressure plate; 52-bolt; 53-anti-loosening gasket; 54-bend. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] A large-diameter, high-temperature hard-seal control ball valve includes a valve body 1 and a valve cover 2. A ball 3 is disposed between the valve body 1 and the valve cover 2, and a valve stem 4 is connected to the ball 3. A groove 31 is provided at the bottom of the ball 3. A support ball 32 is disposed between the groove 31 and the valve body 1. A disc spring 33 and a support ball seat 34 are also disposed between the support ball 32 and the groove 31. The support ball 32, the support ball seat 34, and the disc spring 33 together constitute an elastic support assembly. The ball has an adaptive self-aligning function. The ball 3 forms a low-friction pair with the support ball 32 and the support ball seat 34. Combined with the elastic deformation capability of the disc spring 33, the ball 3 has an adaptive adjustment degree of freedom. This not only significantly reduces the off-center load of the ball on the valve seat, but also effectively compensates for manufacturing tolerances, installation deviations, and differences in high-temperature thermal expansion, ensuring that the ball can be more accurately aligned with the center of the valve seat and fit evenly. This avoids the risk of abnormally increased operating torque or even valve jamming, and improves sealing reliability and service life.

[0022] A valve seat 5 is provided between the ball 3 and the valve cover 2. A valve seat pressure plate 51 is provided on the valve seat 5. The valve seat pressure plate 51 is fixed to the valve cover 2 by bolts 52 and provides pre-tightening force to the valve seat 5, ensuring a stable and reliable initial seal between the valve seat 5 and the valve cover 2. The pre-tightening force applied by the bolts is transmitted to the valve seat through the valve seat pressure plate, ensuring a stable and reliable initial seal between the valve seat and the valve cover. The key advantage of this structural design is that it not only solves the problem of sealing failure and leakage between the valve seat and the valve cover caused by high-temperature thermal expansion, but also, combined with the ball support structure, effectively offsets the significant and asymmetrical lower load force generated by the ball's own weight on the valve seat in large-diameter floating ball valve structures, fundamentally eliminating the risk of sealing failure and leakage caused by this uneven load. This three-point fixing structure effectively prevents bolt loosening, ensuring the long-term reliability of the valve's seal.

[0023] The valve seat pressure plate is provided with a groove corresponding to the position of the bolt 52. An anti-loosening washer 53 is also provided between the bolt 52 and the valve seat pressure plate. The anti-loosening washer 53 is provided with three bent parts 54. When the anti-loosening washer 53 is fitted onto the bolt 52, the bent part at one end is inserted into the groove of the valve seat pressure plate to achieve axial limiting, while the remaining two bent parts are tightly attached to the head of the bolt 52 to achieve circumferential limiting.

[0024] The valve seat 5 and valve body 1 are further reinforced with a hard alloy layer. The mating sealing surfaces are then precision-ground to form a high-precision, high-hardness rigid metal sealing pair. This design completely eliminates the need for easily failing flexible graphite seals, thus providing excellent and durable sealing performance under high-temperature conditions, especially in oxygen-containing environments, effectively solving the leakage problem caused by oxidation and erosion of traditional flexible graphite seals.

[0025] A C-type sealing ring 6 is also provided at the connection between the valve body 1 and the valve cover 2. The C-type sealing ring is made of nickel-based alloy. Its unique design is that the lip of the C-type sealing ring faces the inner side of the valve body cavity. When the pressure of the medium in the cavity increases, the pressure acts on the inner side of the C-type sealing ring, causing it to produce controllable elastic / plastic deformation, driving the lip to press more tightly against the sealing groove wall of the valve body and valve cover, realizing the "pressure self-tightening effect". This structure significantly improves the sealing reliability of the valve at the cavity connection under high temperature and high pressure conditions.

[0026] Please note to all technical personnel: Although this utility model has been described according to the specific embodiments above, the inventive concept of this utility model is not limited to this utility model. Any modification that utilizes the inventive concept will be included within the scope of patent protection of this patent.

[0027] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A large-diameter high-temperature hard-seal control ball valve, comprising a valve body (1) and a valve cover (2), wherein a ball (3) is provided between the valve body (1) and the valve cover (2), and a valve stem (4) is connected to the ball (3), characterized in that, The bottom of the ball (3) is provided with a groove (31), and a support ball (32) is provided between the groove (31) and the valve body (1). A disc spring (33) and a support ball seat (34) are also provided between the support ball (32) and the groove (31). The support ball (32), the support ball seat (34) and the disc spring (33) together constitute an elastic support assembly. The ball (3) forms a low friction pair through the support ball (32) and the support ball seat (34). Combined with the elastic deformation capability of the disc spring (33), the ball (3) is given an adaptive adjustment degree of freedom.

2. The large-diameter high-temperature hard-seal control ball valve according to claim 1, characterized in that, A valve seat (5) is provided between the ball (3) and the valve cover (2). A valve seat pressure plate (51) is also provided on the valve seat (5). The valve seat pressure plate (51) is fixed to the valve cover (2) by bolts (52) and provides pre-tightening force to the valve seat (5) through the valve seat pressure plate (51), so that the sealing surface between the valve seat (5) and the valve cover (2) obtains a stable and reliable initial seal.

3. The large-diameter high-temperature hard-seal control ball valve according to claim 2, characterized in that, The valve seat pressure plate is provided with a slot corresponding to the position of the bolt (52). An anti-loosening washer (53) is also provided between the bolt (52) and the valve seat (5) pressure plate. The anti-loosening washer (53) is provided with three bent parts (54). When the anti-loosening washer (53) is fitted on the bolt (52), the bent part at one end is inserted into the slot of the valve seat pressure plate to achieve axial limiting. At the same time, the remaining two bent parts are tightly attached to the head of the bolt (52) to achieve circumferential limiting.

4. A large-diameter high-temperature hard-seal control ball valve according to claim 2, characterized in that, The valve seat (5) and the valve body (1) are also welded with a hard alloy layer.

5. A large-diameter high-temperature hard-seal control ball valve according to claim 1, characterized in that, A C-shaped sealing ring (6) is also provided at the connection between the valve body (1) and the valve cover (2).

6. A large-diameter high-temperature hard-seal control ball valve according to claim 5, characterized in that, The C-type sealing ring is made of a nickel-based alloy.

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