High-sealing safety valve for natural gas pipeline

Abstract

The utility model discloses a high-sealing safety valve for natural gas pipeline, which relates to the field of safety valve equipment and comprises a first valve body and a second valve body, a sealing component is arranged at the joint of the first valve body and the second valve body and comprises a first flange plate fixedly connected to the top of the first valve body, and a second flange plate fixedly connected to the top of the second valve body. The first flange plate is fixedly connected to the bottom of the first valve body, the second flange plate is fixedly connected to the bottom of the second valve body, the fasteners are located between the first flange plate and the second flange plate, the convex ring is slidably connected with the surface of the first valve body, and first threads are formed in the surface of the convex ring; second threads matched with the first threads are formed in the inner wall of the interior of the protective sleeve, the protective sleeve and the convex ring are matched in a threaded mode to form a sealing cavity for the fastener, the protective sleeve and the convex ring are designed to be matched through trapezoidal threads to form a closed space, the fastener is completely wrapped, external dust, water vapor and corrosive media are effectively isolated, and the service life of the fastener is prolonged. And the threads are prevented from being rusted or blocked.

Description

Technical Field

[0001] The utility model relates to the field of safety valve equipment, in particular to a high-sealing safety valve for natural gas pipelines. Background Art

[0002] During operation, natural gas pipeline systems are susceptible to leakage or structural failure at key connections (such as flanges and valves) due to medium pressure fluctuations, temperature changes, and external environmental factors (such as dust, moisture, and corrosive gases). This can seriously impact pipeline safety and reliability. The sealing performance of flange connections and the long-term stability of fasteners are key issues affecting pipeline safety.

[0003] Traditional flange connections rely on bolts and nuts for fastening. Long-term exposure to humid, hydrogen sulfide (H2S)-containing natural gas environments can easily lead to electrochemical corrosion, causing thread seizure or strength loss. Furthermore, flange connections are prone to creep or aging under high-temperature, high-pressure, or frequent thermal cycling conditions, leading to seal failure. The lack of active protection for fasteners accelerates corrosion when dust and rainwater penetrate into thread gaps, resulting in high maintenance costs. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the existing technology and provide a high-sealing safety valve for natural gas pipelines. The valve is designed with triple protection of sealing chamber isolation fasteners, elastic sealing compensation gap, and anti-loosening structure to suppress vibration, providing effective guarantee for long-term safe operation.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] A high-seal safety valve for a natural gas pipeline includes a first valve body and a second valve body. A sealing assembly is provided at the connection between the first valve body and the second valve body. The sealing assembly includes:

[0007] a first flange, the first flange being fixedly connected to the top of the first valve body;

[0008] a second flange, the second flange being fixedly connected to the bottom of the second valve body;

[0009] at least two fasteners, the fasteners being used to connect the first flange and the second flange into one piece;

[0010] a convex ring, the convex ring being slidably connected to the surface of the first valve body, and a first thread being formed on the surface of the convex ring;

[0011] The protective sleeve is fixedly connected to the surface of the second valve body. A second thread that cooperates with the first thread is provided on the inner wall of the protective sleeve. The protective sleeve cooperates with the convex ring thread to form a sealed chamber for the fastener.

[0012] Preferably, sealing rings are provided between the second flange and the protective sleeve, and between the first flange and the convex ring.

[0013] Preferably, an air inlet channel and a pressure relief channel are provided on the first valve body, a third flange is installed at the outlet of the air inlet channel, and a fourth flange is installed on the pressure relief channel.

[0014] Preferably, a valve stem is provided inside the first valve body, a valve core is installed at the bottom end of the valve stem, a sealing ring is installed in the middle of the valve stem, a baffle is installed at one end of the valve stem that penetrates into the second valve body, and a compression spring is installed on the baffle.

[0015] Preferably, the protective sleeve is made of explosion-proof alloy material, and the inner wall thereof is provided with a trapezoidal thread structure matching the first thread.

[0016] Preferably, a metal spiral wound gasket is provided between the first flange and the second flange.

[0017] The beneficial effects of the utility model are:

[0018] In the utility model, the protective sleeve and the convex ring are designed to cooperate with each other through trapezoidal threads to form a closed space, which completely wraps the fasteners (bolts, nuts), effectively isolates external dust, water vapor and corrosive media, and prevents thread corrosion or clogging; the protective sleeve abuts the bolt head, and the convex ring abuts the nut, mechanically restricting relative rotation, avoiding loosening of the fasteners due to pipeline vibration or pressure fluctuation, and improving connection stability. It is located between the flange and the protective component, filling the fitting gap, enhancing the sealing, and at the same time buffering vibration impact and reducing wear of metal parts. Through the multiple protections of physical isolation (sealed chamber) + elastic sealing (rubber ring) + mechanical anti-loosening (protective sleeve abutment), the pain points of easy rust and loosening of traditional flange connections are solved, and the sealing, durability and maintenance convenience of the safety valve under harsh working conditions are improved. It is suitable for high-pressure, corrosive and frequently vibrating transportation scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of the utility model;

[0020] Figure 2 It is a schematic diagram of the cross-sectional structure of the utility model;

[0021] Figure 3 It is an enlarged structural diagram of point A in FIG2 of the present utility model;

[0022] In the figure, 1. First valve body; 101. Third flange; 102. Fourth flange; 103. First flange; 104. Air inlet passage; 105. Pressure relief passage; 2. Second valve body; 201. Second flange; 3. Sealing assembly; 31. Protective sleeve; 32. Raised ring; 33. Sealing ring; 34. Fastener; 4. Valve stem; 5. Valve core; 6. Sealing ring; 7. Baffle; 8. Compression spring. DETAILED DESCRIPTION

[0023] like Figure 1-Figure 3As shown, a high-sealing safety valve for a natural gas pipeline includes a first valve body 1 and a second valve body 2. A sealing assembly 3 is designed at the connection between the two. The connection is sealed by the sealing assembly 3. The sealing assembly 3 includes a first flange 103, a second flange 201, a plurality of fasteners 34, a convex ring 32, and a protective cover 31 that cooperates with the convex ring 32. The above-mentioned components are connected as follows: the first flange 103 is fixedly connected to the top of the first valve body 1, and the second flange 201 is fixedly connected to the bottom of the second valve body 2; the first flange 103 and the second flange 201 have mounting holes, and the fasteners 34 are subsequently inserted into Inserted into the corresponding mounting hole, the fastener 34 can use a bolt with a nut and cooperate with the nut to connect the first flange 103 and the second flange 201 as a whole. The fastener 34 is used to connect the first flange 103 and the second flange 201 as a whole. However, long-term exposure to the air, dust or rust and other factors cause a certain impact on the fastening strength of the connection. For example, dust accumulates in the thread groove, making it difficult to separate the nut from the bolt. In addition, the fastening strength of the bolt and the nut is reduced due to rust, causing serious damage to the thread, and then the connection between the two flanges becomes loose. Therefore, the connector is sealed, for example: select a convex The ring 32 is slidably connected to the surface of the first valve body 1, and a first thread is provided on the surface of the convex ring 32. The protective sleeve 31 is fixedly connected to the surface of the second valve body 2. A second thread matching the first thread is provided on the inner wall of the protective sleeve 31. The second thread is a trapezoidal thread structure. The protective sleeve 31 and the convex ring 32 are threaded together to form a sealed chamber for the fastener 34. The sealed chamber can protect the fastener 34 from the influence of external wind and sun, and also plays a role in dust isolation. A sealing ring 33 is provided between the second flange 201 and the protective sleeve 31, and between the first flange 103 and the convex ring 32. The upper and lower sealing rings 33 are made of rubber rings. It has a certain elasticity and can seal the gap between the two. In addition, the upper and lower sealing rings 33 have a certain elasticity, which can improve the fitting strength of the threaded connection part between the protective sleeve 31 and the convex ring 32. In addition, after the protective sleeve 31 and the convex ring 32 are threaded together, the protective sleeve 31 abuts on the nut of the bolt, and the convex ring 32 abuts on the nut, thereby limiting and preventing the nut and bolt from rotating relative to each other. The protective sleeve 31 is made of explosion-proof alloy material, and the metal spiral wound gasket between the first flange 103 and the second flange 201 can seal the gap between the connection of the first flange 103 and the second flange 201.

[0024] In addition, an air intake channel 104 and a pressure relief channel 105 are provided on the first valve body 1, and a third flange 101 is installed at the outlet of the air intake channel 104. The air intake pipe with the flange is locked to the third flange 101 by fasteners 34. At the same time, a fourth flange 102 is installed on the pressure relief channel 105, and the pressure relief channel 105 with the flange is also locked to the fourth flange 102 by fasteners 34. The two flanges are installed in the above manner, and the corresponding pipes can be quickly connected externally, and a sealing assembly 3 is installed at the connection between the above two flanges, which can also protect the fasteners 34 there.

[0025] As shown in Figure 2, a valve stem 4 is provided inside the first valve body 1, a valve core 5 is installed at the bottom end of the valve stem 4, and a sealing ring 6 is installed in the middle of the valve stem 4. The sealing ring 6 is used to reduce the flow of gas in the first valve body 1 into the second valve body 2. A baffle 7 is installed at one end of the valve stem 4 that penetrates into the interior of the second valve body 2. A compression spring 8 is installed on the baffle 7. The top of the compression spring 8 abuts against the inner wall of the top of the second valve body 2, and the bottom of the compression spring 8 is fixed on the baffle 7. When the pressure is released, the air pressure in the intake pipe pushes the valve core 5 upward. The valve core 5 and the valve stem 4 are fixedly connected, so that the valve stem 4 moves synchronously. The valve stem 4 pushes the compression spring 8 on the baffle 7 to compress. During the upward movement of the valve core 5, the first valve body 1 is opened and passes through. After the gas enters the first valve body 1 through the intake channel 104, it is discharged through the pressure relief channel 105 to release the excessive air pressure in the pipeline. When the internal pressure of the intake channel 104 is less than the thrust of the compression spring 8, the valve core 5 will block the internal channel of the first valve body 1, providing protection for the safety of the pipeline.

[0026] In summary, this embodiment utilizes flange connections for sealing. A metal spiral wound gasket is located between the first and second flanges, addressing metal interface sealing issues under high-temperature and high-pressure operating conditions. A double rubber seal 33 is located between the flange and the protective assembly, elastically compensating for thread clearance and buffering against vibration-induced loosening. The trapezoidal threads of the protective sleeve 31 and the raised ring 32 form a sealed space, protecting the fastener 34 and achieving dust and rust prevention. The trapezoidal thread structure offers enhanced resistance to axial forces, making it suitable for frequent assembly and disassembly. The anti-loosening design, with the protective sleeve 31 abutting the bolt head and the raised ring 32 abutting the nut, mechanically limits relative rotation and prevents vibration-induced loosening.

Claims

1. A high-sealing safety valve for natural gas pipelines, characterized in that: The invention comprises a first valve body (1) and a second valve body (2), wherein a sealing assembly (3) is provided at the connection between the first valve body (1) and the second valve body (2), and the sealing assembly (3) comprises: A first flange (103), the first flange (103) being fixedly connected to the top of the first valve body (1); A second flange (201), the second flange (201) being fixedly connected to the bottom of the second valve body (2); At least two fasteners (34), the fasteners (34) being used to connect the first flange (103) and the second flange (201) into one body; A convex ring (32), the convex ring (32) is slidably connected to the surface of the first valve body (1), and a first thread is provided on the surface of the convex ring (32); A protective sleeve (31) is fixedly connected to the surface of the second valve body (2), and a second thread that cooperates with the first thread is provided on the inner wall of the protective sleeve (31). The protective sleeve (31) and the convex ring (32) are threadedly cooperated to form a sealed chamber for the fastener (34).

2. A high-sealing safety valve for a natural gas pipeline according to claim 1, characterized in that: A sealing ring (33) is provided between the second flange (201) and the protective sleeve (31), and between the first flange (103) and the convex ring (32).

3. A high-sealing safety valve for a natural gas pipeline according to claim 1, characterized in that: An air intake channel (104) and a pressure relief channel (105) are provided on the first valve body (1); a third flange (101) is installed at the outlet of the air intake channel (104); and a fourth flange (102) is installed on the pressure relief channel (105).

4. A high-sealing safety valve for a natural gas pipeline according to claim 1, characterized in that: A valve stem (4) is provided inside the first valve body (1), a valve core (5) is installed at the bottom end of the valve stem (4), a sealing ring (6) is installed in the middle of the valve stem (4), and a baffle (7) is installed at one end of the valve stem (4) that penetrates into the interior of the second valve body (2), and a compression spring (8) is installed on the baffle (7).

5. The high-sealing safety valve for natural gas pipeline according to claim 1, characterized in that: The protective sleeve (31) is made of explosion-proof alloy material, and the inner wall of the protective sleeve (31) is provided with a trapezoidal thread structure matching the first thread.

6. A high-sealing safety valve for a natural gas pipeline according to claim 1, characterized in that: A metal spiral wound gasket between the first flange (103) and the second flange (201).

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