Sealing structure for low temperature and high pressure and sealing ball valve for low temperature and high pressure

Abstract

The utility model relates to a valve sealing structure, a sealing structure for low temperature and high pressure and a sealing ball valve for low temperature and high pressure, the sealing structure comprises a valve body and a valve seat, an installation cavity is arranged between the valve body and the valve seat, a sealing assembly is arranged in the installation cavity, and the sealing assembly comprises a backing ring, a packing component and a valve seat pressing ring which are sequentially arranged in the direction away from a ball body. The packing component comprises two packing pressing rings and sealing packing arranged between the two packing pressing rings, the sealing packing comprises a metal support and a sealing piece made of thermoplastic fluoroplastic, and the sealing piece is embedded in the contact face, making contact with the packing pressing rings, of the metal support. A spring cavity is formed in the valve seat, a pre-tightening spring is arranged in the spring cavity, and the pre-tightening spring abuts against the valve seat pressing ring, so that the valve seat abuts against the ball body. The metal support enables the sealing filler to have the characteristics of metal, the strength of the sealing filler under the high-pressure working condition is guaranteed, the sealing piece made of the thermoplastic fluoroplastic has good low-temperature resistance, and the sealing performance of the sealing filler under the low-temperature working condition is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of valve sealing structures, in particular to a sealing structure for low temperature and high pressure and a sealing ball valve for low temperature and high pressure. Background Art

[0002] Low temperature and high pressure sealing ball valves are widely used in various pipeline systems for low temperature, high pressure, flammable, explosive and toxic substances, such as liquid hydrogen pipeline transportation systems.

[0003] In the prior art, for example, the prior application with application number "2023233169104" filed by the applicant provides an ultra-low temperature and high pressure self-sealing structure and a self-sealing ball valve, in which an elastic member, a packing pressure ring and a self-sealing packing are used between the valve seat and the valve body. When the medium pressure acts on one end of the packing pressure ring close to the elastic member, a compression force is generated on the self-sealing packing. The pre-tightening force superimposed on the pre-tightening force provided by the elastic member can achieve good sealing under low temperature and high pressure conditions to a certain extent. However, this technical solution still has some defects. For example, the strength and sealing performance of conventional sealing packing are difficult to meet the requirements under low temperature and high pressure environments. Utility Model Content

[0004] The utility model aims to provide a low temperature and high pressure sealing structure and a low temperature and high pressure sealing ball valve to solve the above-mentioned defects of the prior art.

[0005] The embodiments of the present invention are implemented by the following technical solutions:

[0006] A low temperature and high pressure sealing structure, comprising a valve body and a valve seat, an installation cavity is arranged between the valve body and the valve seat, a sealing assembly is arranged in the installation cavity, the sealing assembly comprises a gasket ring, a packing component and a valve seat pressure ring arranged in sequence in a direction away from a sphere, the packing component comprises two packing pressure rings and a sealing packing arranged between the two packing pressure rings, the sealing packing comprises a metal support and a sealing member made of thermoplastic fluoroplastic, and the sealing member is embedded in a contact surface of the metal support contacting the packing pressure ring;

[0007] A spring cavity is provided on the valve seat, and a preload spring is provided in the spring cavity. The preload spring abuts against a valve seat pressure ring so that the valve seat abuts against the ball.

[0008] Optionally, at least one contact surface between the packing pressure ring and the sealing packing is a wedge-shaped structure that fits with each other.

[0009] Optionally, the metal support includes two support blocks symmetrically arranged along a line connecting the two packing pressure rings.

[0010] Optionally, a wave spring is provided between the packing pressure ring and the sealing packing.

[0011] Optionally, two sealing fillers are provided between the two packing pressure rings, and the two sealing fillers are arranged at intervals along a direction perpendicular to a connecting line of the two packing pressure rings.

[0012] Optionally, a metal sealing ring is provided between the valve seat and the gasket.

[0013] The utility model also provides a low-temperature and high-pressure sealing ball valve, comprising any one of the above-mentioned low-temperature and high-pressure sealing structures.

[0014] The technical solution of the present utility model has at least the following advantages and beneficial effects: in the present utility model, the sealing filler includes a metal support and a sealing member made of thermoplastic fluoroplastics, so that the metal support gives the sealing filler the characteristics of metal, thereby ensuring the strength of the sealing filler under high-pressure conditions, and the sealing member made of thermoplastic fluoroplastics has good low-temperature resistance, thereby ensuring the sealing performance of the sealing filler under low-temperature conditions, that is, compared with the prior art, the sealing filler of the present utility model can well meet the sealing requirements under low-temperature and high-pressure conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A structural schematic diagram of a low-temperature and high-pressure sealing structure provided by the utility model;

[0017] Figure 2 It is an enlarged structural schematic diagram of the packing component;

[0018] Icon: 1-valve body, 2-valve seat, 3-gasket, 4-packing part, 401-metal support, 401a-support block, 402-seal, 403-packing pressure ring, 404-wave spring, 5-valve seat pressure ring, 6-preload spring, 7-metal sealing ring, 8-ball. DETAILED DESCRIPTION

[0019] Embodiment 1

[0020] refer to Figure 1The present embodiment provides a sealing structure for low temperature and high pressure, including a valve body 1 and a valve seat 2, an installation cavity is provided between the valve body 1 and the valve seat 2, a sealing assembly is provided in the installation cavity, the sealing assembly includes a gasket ring 3, a packing component 4 and a valve seat 2 pressure ring arranged in sequence in a direction away from the ball 8, a spring cavity is provided on the valve seat 2, and a pre-tightening spring 6 is provided in the spring cavity, and the pre-tightening spring 6 abuts against the valve seat 2 pressure ring. It is easy to understand that after the various parts are installed, the valve seat 2 provides a pre-tightening force under the action of the pre-tightening spring 6, so that the valve seat 2 abuts against the ball 8, thereby realizing the sealing between the valve seat 2 and the ball 8.

[0021] refer to Figure 2 The packing component 4 includes two packing pressure rings 403 and a sealing packing arranged between the two packing pressure rings 403. The sealing packing includes a metal support 401 and a sealing member 402 made of thermoplastic fluoroplastics. The sealing member 402 is embedded in the contact surface of the metal support 401 and the packing pressure ring 403. It is worth noting that, in such a configuration, the metal support 401 makes the sealing packing have the characteristics of metal, ensuring the strength of the sealing packing under high-pressure conditions, and the sealing member 402 made of thermoplastic fluoroplastics has good low-temperature resistance, ensuring the sealing performance of the sealing packing under low-temperature conditions, that is, compared with the prior art, the sealing packing of the utility model can well meet the sealing requirements under low-temperature and high-pressure conditions.

[0022] The specific material of the metal support 401 is not limited, and it is not difficult to understand from the above description that the metal support 401 should be a pressure-resistant hard metal. The material of the seal 402 is preferably PCTFE, and of course in other embodiments, other thermoplastic fluoroplastics such as THV, PVDF, ETFE, etc. can also be selected.

[0023] In this embodiment, two sealing fillers are arranged between the two packing pressure rings 403, and the two sealing fillers are arranged along a direction perpendicular to the connecting line of the two packing pressure rings 403 (i.e. Figure 2 In this way, the number of sealing surfaces is increased and the sealing performance is improved.

[0024] In this embodiment, a contact surface between the packing pressure ring 403 and the sealing packing is a wedge-shaped structure that fits each other. This arrangement allows the medium pressure to have a tightening effect, thereby improving the sealing pressure ratio of the sealing surface. The effect is more significant, especially under high-pressure conditions. It should be understood that in other embodiments, of course, both contact surfaces can be designed as wedge-shaped structures, that is, the groove on the packing pressure ring 403 and the sealing packing are both trapezoidal in shape. Furthermore, the metal support 401 includes a groove along the direction of the connection line of the two packing pressure rings 403 (i.e. Figure 2 Two support blocks 401a are symmetrically arranged in the left and right directions to facilitate installation.

[0025] On the basis of the above, a wave spring 404 is provided between the packing pressure ring 403 and the sealing packing to provide a certain deformation capacity to prevent locking.

[0026] Furthermore, in this embodiment, a metal sealing ring 7 is provided between the valve seat 2 and the gasket 3 to ensure sufficient strength and overcome the defects of traditional plastic sealing rings. Moreover, the metal sealing ring 7 and the sealing assembly form a double seal to ensure the safety of the seal.

[0027] Embodiment 2

[0028] This embodiment provides a low-temperature and high-pressure sealed ball valve, which adopts the low-temperature and high-pressure sealing structure provided in the first embodiment.

[0029] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low temperature and high pressure sealing structure, comprising a valve body (1) and a valve seat (2), wherein an installation cavity is provided between the valve body (1) and the valve seat (2), characterized in that: A sealing assembly is provided in the installation cavity, the sealing assembly comprising a gasket ring (3), a packing component (4) and a valve seat (2) pressure ring arranged in sequence in a direction away from the ball (8), the packing component (4) comprising two packing pressure rings (403) and a sealing packing arranged between the two packing pressure rings (403), the sealing packing comprising a metal support (401) and a sealing member (402) made of thermoplastic fluoroplastic, the sealing member (402) being embedded in a contact surface of the metal support (401) contacting the packing pressure ring (403); A spring chamber is provided on the valve seat (2), and a preload spring (6) is provided in the spring chamber. The preload spring (6) abuts against a pressure ring of the valve seat (2) so that the valve seat (2) abuts against the ball (8).

2. The low temperature and high pressure sealing structure according to claim 1, characterized in that: At least one contact surface between the packing pressure ring (403) and the sealing packing is a wedge-shaped structure that fits with each other.

3. The low temperature and high pressure sealing structure according to claim 2, characterized in that: The metal support (401) comprises two support blocks (401a) which are symmetrically arranged along the connecting line direction of the two packing pressure rings (403).

4. The low temperature and high pressure sealing structure according to claim 2, characterized in that: A wave spring (404) is provided between the packing pressure ring (403) and the sealing packing.

5. The low temperature and high pressure sealing structure according to any one of claims 1 to 3, characterized in that: Two sealing fillers are arranged between the two packing pressure rings (403), and the two sealing fillers are arranged at intervals in a direction perpendicular to the connecting line of the two packing pressure rings (403).

6. The low temperature and high pressure sealing structure according to any one of claims 1 to 3, characterized in that: A metal sealing ring (7) is provided between the valve seat (2) and the gasket (3).

7. A low temperature and high pressure sealed ball valve, characterized in that: A sealing structure for low temperature and high pressure comprising the sealing structure according to any one of claims 1 to 6.

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