Valve cover sealing structure of high-temperature ball valve

Abstract

The utility model relates to a high-temperature ball valve bonnet sealing structure, which belongs to the technical field of valves and comprises a valve body and a bonnet, the bonnet is fixed on the valve body through bolts, the bonnet is of a lengthened structure, radiating fins are arranged on the outer side of the bonnet, and a self-tightening sealing component and a high-temperature-resistant winding gasket are arranged between the bonnet and the valve body. The self-tightening sealing assembly is composed of a packing chamber, a self-tightening metal sealing ring, a corrugated pipe, a disc spring and the like, the valve rod is arranged in the valve cover, and the lower end of the valve rod penetrates through the valve body to be connected with the ball. The self-tightening sealing assembly and the high-temperature spiral wound gasket are used in cooperation for sealing, the sealing performance is good, leakage is not prone to occurring, and the problem that the ball valve deck is difficult to connect and seal under the high-pressure and ultra-high-temperature working conditions is solved. The structure is also suitable for the high-temperature butterfly valve cover.

Description

Technical Field

[0001] The utility model belongs to the technical field of valves, and in particular relates to a high-temperature ball valve cover sealing structure. Background Art

[0002] At present, with the application of ball valves in the field of high temperature resistance, higher requirements are put forward for the high temperature sealing performance of ball valves. However, for valve covers connected by conventional bolts, high temperature will reduce the strength of the bolt material, resulting in a certain degree of relaxation, and the bolts will slowly deform when working for a long time at high temperature, and stress relaxation will also occur. When creep occurs, the length of the bolt will increase, resulting in an increase in the distance between the nuts on both sides of the bolt, and the sealing performance will be reduced, causing major safety risks. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a high-temperature ball valve cover sealing structure. The technical solution adopted by the utility model is as follows:

[0004] A high-temperature ball valve bonnet sealing structure comprises a valve body and a bonnet. The bonnet is fixed to the valve body by bolts. The bonnet adopts an extended structure and is provided with a heat sink on the outside. A self-tightening sealing component and a high-temperature resistant spiral wound gasket are provided between the bonnet and the valve body. The self-tightening sealing component consists of a packing chamber, a self-tightening metal sealing ring, a bellows, and a disc spring. A valve stem is arranged in the bonnet, and the lower end of the valve stem passes through the valve body and is connected to the ball.

[0005] A bellows is arranged between the stuffing chamber and the valve cover in the self-tightening sealing assembly, one end of the bellows is welded to the valve cover, and the other end is welded to the stuffing chamber, a self-tightening metal sealing ring is installed on the inclined platform of the stuffing chamber and connected to the valve cover, a disc spring is arranged between the stuffing chamber and the valve body, and a boss is arranged on the valve cover to limit the displacement of the self-tightening sealing assembly along the axial direction of the valve stem.

[0006] Furthermore, a self-tightening sealing component and a high-temperature resistant spiral wound gasket are provided between the valve cover and the valve body. The self-tightening sealing component serves as a first-level seal, and the high-temperature resistant spiral wound gasket serves as a second-level seal.

[0007] Furthermore, radial sealing between the packing chamber and the valve cover is achieved by the bellows, and the axial expansion and contraction of the bellows can offset the axial displacement of the self-tightening sealing component along the valve stem.

[0008] Furthermore, the self-tightening metal sealing ring is installed on the inclined platform of the packing chamber and connected to the valve cover. The valve cover is provided with a boss to limit the displacement of the self-tightening sealing component along the axial direction of the valve stem. Under the action of the valve medium pressure, the annular surface composed of the outer circle of the self-tightening metal sealing ring and the inner circle of the bellows seal causes the packing chamber to move outward along the axial direction of the valve stem. The packing chamber pushes the self-tightening metal sealing ring to be squeezed between the inclined platform of the packing chamber and the inner wall of the valve body, thereby realizing the sealing between the valve body and the packing chamber. The higher the pressure, the better the self-sealing effect.

[0009] Furthermore, the disc spring is arranged between the packing chamber and the valve body, so that the self-tightening metal sealing ring is tightly fitted with the valve body and the packing chamber under the action of the pre-tightening force of the disc spring, forming an initial sealing state.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] The utility model provides a high-temperature ball valve cover sealing structure, which adopts a self-tightening sealing component and a high-temperature resistant spiral wound gasket combined sealing structure.

[0012] The valve cover and the valve body are set as a two-stage sealing structure, and the self-tightening sealing component and the high-temperature resistant spiral wound gasket are used in combination. The self-tightening sealing component is the first-stage sealing. The high-temperature medium in the valve cover and the valve body is isolated from the outside world through the self-tightening sealing component. The self-tightening metal sealing ring realizes the sealing between the packing chamber and the valve body, and the bellows realizes the radial sealing between the packing chamber and the valve cover. The two parts of the seal realize the sealing closed loop between the valve cover, the valve body and the outside world; the disc spring set between the packing chamber and the valve body pre-tightens the self-tightening metal sealing ring to ensure that the self-tightening metal sealing ring can also play a sealing role under low pressure. When the pressure of the medium in the valve increases, the annular surface formed by the outer circle of the self-tightening metal sealing ring and the inner circle of the bellows seal causes the packing chamber to move outward along the axial direction of the valve stem under the action of the valve medium pressure. The packing chamber pushes the self-tightening metal sealing ring to squeeze on the packing chamber ramp and the inner wall of the valve body, realizing the sealing between the valve body and the packing chamber under high pressure conditions. At the same time, since the bellows is installed between the packing chamber and the valve cover, the axial expansion and contraction of the bellows can offset the displacement of the self-tightening sealing component along the axial direction of the valve stem. All parts of the self-tightening sealing assembly are made of pure metal and can work for a long time in high temperature and high pressure medium conditions.

[0013] The second-stage seal between the valve cover and the valve body adopts a high-temperature resistant spiral wound gasket, which is tightened by bolts and plays a sealing role when the first-stage seal fails or there is a slight leak. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the utility model;

[0015] Figure 2 Yes Figure 1 A schematic diagram of the enlarged structure at the mark A.

[0016] In the figure: 1-valve body, 2-ball, 3-valve stem, 4-valve cover, 5-bolt, 6-disc spring, 7-stuffing chamber, 8-self-tightening metal sealing ring, 9-high temperature resistant spiral wound gasket, 10-bellows. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is described below by specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0019] Example: Figure 1 As shown, the utility model relates to a high-temperature ball valve bonnet structure, comprising a valve body (1), a bonnet (4), a ball (2) arranged in the valve body (1), a valve seat sealing assembly, a packing sealing structure arranged on the top of the bonnet (4), and a connection arrangement between an actuator and a valve stem (3). This is a prior art and will not be elaborated or limited in detail herein. The bonnet (4) is fixed to the valve body (1) by bolts (5), the bonnet (4) adopts an extended structure and is provided with a heat sink on the outside, and a high-temperature resistant spiral wound gasket (9) is provided at the joint position between the bonnet (4) and the valve body (1) to ensure that the self-tightening sealing assembly plays a sealing role when it fails or leaks slightly.

[0020] The self-tightening sealing assembly comprises a packing chamber (7), a self-tightening metal sealing ring (8), a bellows (10), and a disc spring (6). The bellows (10) is arranged between the packing chamber (7) and the valve cover (4). One end of the bellows (10) is welded to the valve cover (4), and the other end is welded to the packing chamber (7). The bellows (10) realizes radial sealing between the packing chamber (7) and the valve cover (4). At the same time, the axial expansion and contraction of the bellows (10) can offset the axial displacement of the self-tightening sealing assembly along the valve stem (3); the self-tightening metal sealing ring (8) is installed on the inclined platform of the packing chamber (7) and connected to the valve cover (4). The self-tightening metal sealing ring (8) realizes sealing between the packing chamber (7) and the valve body (1); the bellows (10) and the self-tightening metal sealing ring (8) The two-part sealing member realizes a sealed closed loop between the valve cover (4), the valve body (1) and the outside, and forms a self-tightening sealing structure. When the pressure of the medium in the valve increases, the annular surface formed by the outer circle of the self-tightening metal sealing ring (8) and the inner circle of the bellows (10) seal causes the packing chamber (7) to move outward along the axial direction of the valve stem (3) under the action of the valve medium pressure. The packing chamber (7) pushes the self-tightening metal sealing ring (8) to be squeezed on the packing chamber (7) ramp and the inner wall of the valve body (1), thereby realizing the sealing between the valve body (1) and the packing chamber (7) under high pressure conditions; the disc spring (6) is installed between the packing chamber (7) and the valve body (1) to pre-tighten the self-tightening metal sealing ring (8), thereby ensuring that the self-tightening metal sealing ring (8) can also play a sealing role under low pressure. The axial limit of the self-tightening sealing component is realized by the valve cover (4).

[0021] The above embodiments are merely illustrative of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, and as long as they do not exceed the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A high-temperature ball valve cover (4) sealing structure, characterized in that: The invention comprises a valve body (1) and a valve cover (4). The valve cover (4) is fixed to the valve body (1) by bolts (5). The valve cover (4) adopts an extended structure and is provided with a heat sink on the outer side. A self-tightening sealing component and a high-temperature resistant spiral wound gasket (9) are provided between the valve cover (4) and the valve body (1). The self-tightening sealing component is composed of a stuffing chamber (7), a self-tightening metal sealing ring (8), a bellows (10), and a disc spring (6). A valve stem (3) is arranged in the valve cover (4). The lower end of the valve stem (3) passes through the valve body (1) and is connected to the ball (2). A bellows (10) is arranged between the stuffing chamber (7) and the valve cover (4) in the self-tightening sealing assembly. One end of the bellows (10) is welded to the valve cover (4), and the other end is welded to the stuffing chamber (7). A self-tightening metal sealing ring (8) is installed on the inclined platform of the stuffing chamber (7) and connected to the valve cover (4). A disc spring (6) is arranged between the stuffing chamber (7) and the valve body (1). The valve cover (4) is provided with a boss to limit the displacement of the self-tightening sealing assembly along the axial direction of the valve stem (3).

2. A high-temperature ball valve cover (4) sealing structure as claimed in claim 1, characterized in that: A self-tightening sealing component and a high-temperature resistant spiral wound gasket (9) are provided between the valve cover (4) and the valve body (1), the self-tightening sealing component serving as a first-level seal, and the high-temperature resistant spiral wound gasket (9) serving as a second-level seal.

3. A high-temperature ball valve cover (4) sealing structure as claimed in claim 1, characterized in that: The bellows (10) is used to achieve radial sealing between the packing chamber (7) and the valve cover (4), while the axial expansion and contraction of the bellows (10) can offset the axial displacement of the self-tightening sealing component along the valve stem (3).

4. A high-temperature ball valve cover (4) sealing structure as claimed in claim 1, characterized in that: The self-tightening metal sealing ring (8) is installed on the inclined platform of the packing chamber (7) and connected to the valve cover (4). The valve cover (4) is provided with a boss to limit the displacement of the self-tightening sealing component along the axial direction of the valve stem (3). Under the action of the valve medium pressure, the annular surface formed by the outer circle of the self-tightening metal sealing ring (8) and the sealing inner circle of the bellows (10) causes the packing chamber (7) to move outward along the axial direction of the valve stem (3). The packing chamber (7) pushes the self-tightening metal sealing ring (8) to be squeezed between the inclined platform of the packing chamber (7) and the inner wall of the valve body (1), thereby achieving sealing between the valve body (1) and the packing chamber (7). The higher the pressure, the better the self-sealing effect.

5. A high-temperature ball valve cover (4) sealing structure as claimed in claim 1, characterized in that: The disc spring (6) is arranged between the packing chamber (7) and the valve body (1), so that the self-tightening metal sealing ring (8) is tightly fitted with the valve body (1) and the packing chamber (7) under the action of the pre-tightening force of the disc spring (6), thereby forming an initial sealing state.

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