A double valve seat structure with independent sealing

Abstract

The invention discloses a double valve seat structure with independent seal, which comprises a valve seat, a ball and a valve body. The valve seat is composed of a small valve seat and a big valve seat. The outer periphery of the back end of the small valve seat is a stepped shaft, which is matched with the inner cavity of the big valve seat. The one end surface of the stepped shaft is in contact with the loading spring I installed in the inner cavity of the big valve seat. The other end surface of the stepped shaft is sealed with the inner cavity of the big valve seat through O ring I. The front end of the small valve seat is connected with the ball through the first reseal triangle seal ring I. The front end of the big valve seat is connected with the ball through the second reseal triangle seal ring II. The back end of the big valve seat is sealed with the valve body through O ring II, and is in contact with the loading spring II installed on the valve body. The invention is suitable for the working condition of special and difficult sealing medium, such as hydrogen, and has simple structure and strong practicability.

Description

Technical Field

[0001] This invention relates to the field of valve manufacturing technology, specifically to a double-seat structure with independent sealing. Background Technology

[0002] The rapid development of the hydrogen energy industry has led to a continuous increase in the construction of hydrogen pipelines, resulting in a sustained growth in demand for fully welded ball valves for these pipelines. The research and application of fully welded ball valves for hydrogen pipelines can drive technological progress and industrial upgrading in the valve manufacturing industry. To address the leakage problem between the valve seat and the ball in fully welded ball valves suitable for gaseous pure hydrogen media, existing technologies employ a dual-seat sealing structure. However, in this structure, the two valve seats share a single spring, and the medium force at the inlet and outlet ends only acts on the smaller valve seat. During sealing, the two valve seats interact with each other. The problem is that in this dual-seat sealing structure, the smaller valve seat plays the primary sealing role. If the sealing pair fails, the larger valve seat must perform the sealing function. Sufficient spring force is required to ensure a seal between the larger valve seat and the ball. This invention provides a dual-seat structure with independent sealing, which solves the above problems. Summary of the Invention

[0003] This invention provides a dual-seat structure with independent sealing, which realizes the dual sealing function of two independent valve seats without interference, and can solve the problem of difficult sealing of media such as hydrogen, ensuring the reliability of the valve seat and ball seal.

[0004] The technical solution adopted in this invention is: A dual-seat structure with independent sealing includes a valve seat, a ball, and a valve body. The valve seat consists of a small valve seat and a large valve seat. The outer circumference of the rear end of the small valve seat is a stepped shaft, which is adapted to the inner cavity of the large valve seat. One end face of the stepped shaft is in contact with a loading spring I installed in the inner cavity of the large valve seat, and the other end face of the stepped shaft is sealed to the inner cavity of the adapted large valve seat by an O-ring I. The front end of the small valve seat forms a first seal with the ball through a triangular sealing ring I. The front end of the large valve seat forms a second seal with the ball through a triangular sealing ring II. The rear end of the large valve seat is sealed to the valve body by an O-ring II and is in contact with a loading spring II installed on the valve body.

[0005] The triangular sealing ring I and the small valve seat, and the triangular sealing ring II and the large valve seat are both interference fit seals. Moreover, the small valve seat and the large valve seat near the triangular sealing ring I and triangular sealing ring II are respectively provided with retaining groove I and retaining groove II.

[0006] In this invention, the small valve seat and the large valve seat are independent of each other and do not affect each other; the small valve seat and the ball form the first layer of seal, and the large valve seat and the ball form the second layer of seal, thus providing a double sealing effect. If the first layer of seal between the small valve seat and the ball fails, the large valve seat and the ball form the second layer of seal, providing the main sealing effect and ensuring a leak-free seal between the valve seat and the ball. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the small valve seat sealing structure of the present invention; Figure 3 This is a schematic diagram of the large valve seat sealing structure of the present invention. Detailed Implementation

[0008] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0009] Reference Figure 1-3 A dual-seat structure with independent sealing includes a valve seat, a ball 1, and a valve body 4. The valve seat consists of a small valve seat 2 and a large valve seat 3. The outer circumference of the rear end of the small valve seat 2 is a stepped shaft, which is adapted to the inner cavity of the large valve seat 3. One end face of the stepped shaft is in contact with a loading spring I2-3 installed in the inner cavity of the large valve seat 3. The other end face of the stepped shaft is sealed to the inner cavity of the adapted large valve seat 3 by an O-ring I2-2. The front end of the small valve seat 2 forms a first seal with the ball 1 through a triangular sealing ring I2-1. The front end of the large valve seat 3 forms a second seal with the ball 1 through a triangular sealing ring II3-1. The rear end of the large valve seat 3 is sealed to the valve body 4 by an O-ring II3-2 and is in contact with the loading spring II3-3 installed on the valve body 4.

[0010] The first and second loading springs respectively apply a certain preload to the small valve seat 2 and the large valve seat 3. The small valve seat 2 and the large valve seat 3 are both subjected to the combined action of the medium force and the loading spring force, which provides sufficient sealing force between the small valve seat 2, the large valve seat 3 and the ball 1, ensuring reliable sealing between the small valve seat 2, the large valve seat 3 and the ball 1.

[0011] The triangular sealing ring I2-1 and the small valve seat 2, and the triangular sealing ring II3-1 and the large valve seat 3 are both interference fit seals. Furthermore, the small valve seat 2 and the large valve seat 3 adjacent to the triangular sealing rings I2-1 and II3-1 respectively are provided with retaining grooves I2-4 and II3-4 to prevent the triangular sealing rings from being squeezed out by the ball 1.

Claims

1. A dual-seat structure with independent sealing, comprising a valve seat, a ball, and a valve body, characterized in that, The valve seat is composed of a small valve seat (2) and a large valve seat (3). The outer periphery of the rear end of the small valve seat (2) is a stepped shaft. The stepped shaft is adapted to the inner cavity of the large valve seat (3). One end face of the stepped shaft is in contact with the loading spring I (2-3) installed in the inner cavity of the large valve seat (3). The other end face of the stepped shaft is sealed to the inner cavity of the adapted large valve seat (3) by O-ring I (2-2). The front end of the small valve seat (2) forms a first seal with a triangular sealing ring I (2-1) and a ball (1). The front end of the large valve seat (3) forms a second seal with a triangular sealing ring II (3-1) and a ball (1). The rear end of the large valve seat (3) is sealed to the valve body (4) by O-ring II (3-2) and is in contact with the loading spring II (3-3) installed on the valve body (4).

2. The dual-seat structure with independent sealing according to claim 1, characterized in that, The triangular sealing ring I (2-1) and the small valve seat (2), and the triangular sealing ring II (3-1) and the large valve seat (3) are both interference fit seals. Moreover, the small valve seat (2) and the large valve seat (3) adjacent to the triangular sealing ring I (2-1) and the triangular sealing ring II (3-1) are respectively provided with retaining groove I (2-4) and retaining groove II (3-4).

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