Connecting seal structure of a boron trifluoride gas stop valve

Abstract

This utility model discloses a connection and sealing structure for a boron trifluoride gas shut-off valve, including a valve body, a pressure cap threaded to the top of the valve body, a pressure sleeve snapped into the middle of the pressure cap, a valve stem threaded to the middle of the pressure sleeve, and a valve core assembly at the bottom of the valve stem. The valve core assembly includes a valve core rod rotatably connected to the bottom of the valve stem, a valve seat fixed to the bottom of the valve core rod, and a flange fitted on the outer surface of the valve core rod. Compared with the traditional connection and sealing structure of boron trifluoride gas shut-off valves, this utility model improves the convenience of installation and disassembly of the shut-off valve through the valve body, pressure cap, pressure sleeve, valve stem, handwheel, and valve core assembly; improves the stability of gas intake through the cooperation of the sealing seat, second sealing gasket, and pad; and improves the sealing performance of exhaust gas through the valve core rod, valve seat, flange, first sealing gasket, and liner. This also improves the convenience of disassembly and maintenance of the shut-off valve, extends its service life, and reduces maintenance costs.

Description

Technical Field

[0001] This utility model relates to the field of cylinder valves, and more particularly to the connection and sealing structure of a boron trifluoride gas shut-off valve. Background Technology

[0002] Boron trifluoride (BF3) is an inorganic compound gas composed of boron and fluorine. Boron trifluoride is a typical Lewis acid and can form stable complexes with Lewis bases such as amines and ethers. A gate valve is a valve that controls the flow of media by the linear movement of the valve disc along the center line of the valve seat. Gate valves are used to control the discharge of boron trifluoride.

[0003] The core structure of the existing boron trifluoride gas shut-off valve includes a valve disc, a valve seat, a valve stem, and a valve body. The valve disc is plug-shaped, and the sealing surface is a plane or a cone. Pressure is transmitted through the valve stem to make the valve disc fit tightly against the valve seat, thereby blocking the flow of the medium; reverse operation opens the passage.

[0004] The existing boron trifluoride gas gate valves typically use an integrated sealing seat structure. Since boron trifluoride gas is corrosive, the valve can become unusable after prolonged contact with the highly corrosive gas, requiring the entire valve seat to be replaced. This reduces the lifespan of the gate valve and increases maintenance and replacement costs. Utility Model Content

[0005] To overcome the problem that the existing boron trifluoride gas gate valves typically use an integrated sealing structure, which is corrosive to boron trifluoride gas, the sealing parts of the valve can become corroded and unusable after prolonged contact with the highly corrosive gas, requiring the entire valve seat to be replaced. This reduces the service life of the gate valve and increases maintenance and replacement costs.

[0006] The technical solution of this utility model is as follows: It includes a valve body: a pressure cap is threaded to the top of the valve body, a pressure sleeve is snapped into the middle of the pressure cap, the valve body is threaded to the outer side of the pressure sleeve, a valve stem is threaded to the middle of the pressure sleeve, a valve core assembly is provided at the bottom of the valve stem, the valve core assembly includes a valve core rod rotatably connected to the bottom of the valve stem, a valve seat is fixed at the bottom of the valve core rod, a flange is sleeved on the outer surface of the valve core rod, a first sealing gasket is sleeved at the bottom of the valve core rod near the flange, a gasket is snapped into the bottom of the first sealing gasket, a sealing seat is snapped into the inner bottom of the valve body, a second sealing gasket is sleeved at the bottom of the sealing seat, and a through groove is opened in the middle of the sealing seat.

[0007] Furthermore, a connecting block is fixed at the top of the valve core rod, and the connecting block is rotatably connected to the middle of the lower end of the valve core rod, which improves the stability of the valve core rod rotation.

[0008] Furthermore, a pad is snapped into the bottom of the valve seat, and the bottom of the pad is supported on the top of the sealing seat, which improves the sealing performance of the through groove.

[0009] Furthermore, a plug is threaded onto the side wall of the valve body, and a third sealing gasket is snapped onto the inner side wall of the plug, which improves the convenience of sealing the valve body.

[0010] Furthermore, a threaded groove is provided in the middle of the valve body for the positive thread connection of the pressure sleeve. The pressure cap is fitted on the top of the pressure sleeve, and the top of the valve stem passes through the pressure sleeve.

[0011] Furthermore, a handwheel is fixed to the top of the pressure sleeve, and an anti-slip groove is provided on the side wall of the handwheel.

[0012] Furthermore, the flange, the first sealing gasket, and the liner are adapted to the internal dimensions of the valve body, and the top of the liner is snapped into the bottom of the first sealing gasket, which improves the sealing performance of the valve core rod.

[0013] Furthermore, an transition sleeve is fitted onto the inner wall of the valve body near the sealing seat, and the transition sleeve is fitted onto the outer surface of the valve seat.

[0014] The beneficial effects of this utility model are: Compared to the traditional boron trifluoride gas shut-off valve's connection and sealing structure, the valve body, pressure cap, pressure sleeve, valve stem, handwheel, and valve core assembly improve the ease of installation and disassembly of the shut-off valve. The combination of the sealing seat, second sealing gasket, and gasket block enhances the stability of the intake air. The valve core rod, valve seat, pressure flange, first sealing gasket, and liner improve the sealing performance of the exhaust air. This also increases the ease of disassembly and maintenance of the shut-off valve, extends its service life, and reduces maintenance costs. Attached Figure Description

[0015] Figure 1 The diagram shown is a schematic representation of the overall structure of the connection and sealing structure of the boron trifluoride gas shut-off valve of this utility model. Figure 2 The diagram shown is a schematic cross-sectional view of the overall structure of this utility model. Figure 3 The diagram shown is a schematic representation of the overall unfolded structure of this utility model. Figure 4 The diagram shown is a cross-sectional view of the pressure sleeve of this utility model. Figure 5 The diagram shown is a cross-sectional view of the sealing seat of this utility model.

[0016] Explanation of reference numerals in the attached drawings: 1. Valve body; 2. Pressure cap; 3. Pressure sleeve; 4. Valve stem; 5. Handwheel; 6. Plug cap; 7. Sealing seat; 8. Valve core assembly; 801. Valve core rod; 802. Valve seat; 803. Connecting block; 804. Gasket; 9. Pressure flange; 10. First sealing gasket; 11. Liner; 12. Second sealing gasket; 13. Third sealing gasket; 15. Threaded groove; 16. Transition sleeve; 17. Through groove. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Please refer to Figures 1-5The connection and sealing structure of the boron trifluoride gas shut-off valve includes a valve body 1, which is made of stainless steel and used for support and limiting. An air inlet is provided at the bottom of the valve body 1. The valve body 1 can be fixed by a threaded connection. A pressure cap 2 is threaded to the top of the valve body 1. A pressure sleeve 3 is snapped into the middle of the pressure cap 2. The valve body 1 is threaded to the outer side of the pressure sleeve 3, and a valve stem 4 is threaded to the middle. A valve core assembly 8 is provided at the bottom of the valve stem 4. The valve core assembly 8 includes a valve core rod 801 rotatably connected to the bottom of the valve stem 4. The top of the valve core rod 801 is fixed... A connecting block 803 is provided, which is rotatably connected to the middle of the lower end of the valve stem 4, improving the stability of the valve core rod 801 rotation. A valve seat 802 is fixed to the bottom end of the valve core rod 801. The sealing block 804 inside the valve seat 802 is a planar seal made of high-molecular-weight polytetrafluoroethylene (PTFE) material. PTFE material typically refers to a polymer compound polymerized from trifluoroethylene monomers. The molecular chain of PTFE material contains a large number of fluorine atoms, possessing excellent chemical corrosion resistance, high and low temperature resistance, and a certain mechanical strength. This seal is achieved through the valve stem 4... The lifting mechanism drives the lifting of the 804 sealing block, which in turn cooperates with the sealing seat 7 to control the valve opening and closing. The outer surface of the valve core rod 801 is fitted with a flange 9. The bottom end of the valve core rod 801 near the flange 9 is fitted with a first sealing gasket 10. The bottom end of the first sealing gasket 10 is snapped with a liner 11. The flange 9, the first sealing gasket 10, and the liner 11 are respectively adapted to the internal dimensions of the valve body 1. The top end of the liner 11 is snapped with the bottom end of the first sealing gasket 10. The 804 high-molecular polytetrafluoroethylene material wrapped inside the valve seat 802 seals with the sealing seat 7, forming the first sealing defense line. The chemical corrosion resistance of the material itself resists the corrosion of boron trifluoride gas.The combination of the pressure flange 9, the first sealing gasket 10, and the liner 11 forms a radial seal on the valve core rod 801, preventing gas leakage along the valve core rod gap. The second sealing gasket 12 at the bottom of the sealing seat 7 further enhances the seal between the through groove 17 and the bottom of the valve body 1. The multi-level sealing structure works together to significantly reduce the risk of seal failure, especially suitable for easily leaking and highly corrosive gas media such as boron trifluoride. Rotating the pressure cap 2 can adjust the sealing performance at the top of the valve. The sealing seat 7 is snapped into the inner bottom of the valve body 1. Through the cooperation of the pressure cap 2, pressure sleeve 3, valve stem 4, sealing seat 7, and valve core assembly 8, gas can be prevented from contacting the pressure sleeve 3, thereby avoiding the "seizing" phenomenon and improving the stability of valve use. When the valve stem 4 is rotated clockwise, the cooperation of the valve stem 4, valve core rod 801, and sealing seat 7 can prevent excessive torque from damaging the sealing structure. The bottom end of the sealing seat 7 is fitted with the second sealing gasket 12, and the middle of the sealing seat 7 has a through groove 17. When the internal parts of the gate valve age and need to be replaced, the operation... Personnel can rotate the pressure cap 2 clockwise to separate the valve body 1 and the pressure cap 2, and then raise the valve stem 4 clockwise to the top limit. At this time, by rotating the pressure sleeve 3 counterclockwise, the pressure sleeve 3, valve core rod 801, valve seat 802, transition sleeve 16, sealing seat 7, and second sealing gasket 12 can be easily pulled out from the inside of the valve body 1 in sequence, thereby improving the convenience of disassembly and maintenance of the gate valve. The rotating connection structure between the connecting block 803 and the valve stem 4 in the valve core assembly 8 ensures the rotation flexibility of the valve core rod 801 and avoids wear on the sealing surface caused by the force deviation of the valve core rod. The torque buffer design when rotating the valve stem 4 clockwise can prevent deformation of the sealing block 804 and the sealing seat 7 due to rigid collision, reducing damage to the sealing surface. At the same time, the high-molecular polytetrafluoroethylene material of the sealing block 804 has a certain degree of elasticity, which can compensate for assembly errors or slight wear through small deformation, extending the replacement cycle of the seals. The detachable structure design not only simplifies the replacement process, but also reduces the special tools and operation time required for maintenance.

[0019] An exhaust port is provided on the side wall of the valve body 1. A plug 6 is threadedly connected to the side wall of the valve body 1. The plug 6 is used to seal the exhaust port. A third sealing gasket 13 is snapped into the inner side wall of the plug 6, which improves the convenience and sealing performance of the valve body 1. The operator can turn the plug 6 clockwise to open the exhaust port. The exhaust port on the side wall of the valve body 1 can be vented through a threaded connection pipe.

[0020] A threaded groove 15 is provided in the middle of the valve body 1, which is used for the positive thread connection of the pressure sleeve 3. The pressure cap 2 is fitted on the top of the pressure sleeve 3, and the top of the valve stem 4 passes through the pressure sleeve 3, which improves the stability of the rotation of the valve stem 4 and the valve core rod 801. The top of the pressure sleeve 3 passes through the pressure cap 2, and the top of the valve stem 4 is fixed with a handwheel 5 by bolts. The side wall of the handwheel 5 has an anti-slip groove. Turning the handwheel 5 can drive the valve stem 4 to rotate, thereby facilitating the adjustment of the raising and lowering of the valve stem 4. The thread on the outside of the pressure sleeve and the thread 15 on the top of the valve body 1 form a precise circumferential positioning structure. The locking of the pressure cap 2 can prevent the pressure sleeve 3 from radially offset or rotating when the valve is opened or closed. This "positive and negative double thread fixing" method can better resist the reaction force generated when the valve stem 4 rotates compared with a single thread connection, reduce the loosening of the pressure sleeve 3 during use, further ensure the support stability of the pressure sleeve 3 for the valve stem 4, and indirectly reduce the risk of leakage during valve use.

[0021] An transition sleeve 16 is snapped onto the inner wall of the valve body 1 near the sealing seat 7, and the transition sleeve 16 is fitted onto the outer surface of the valve seat 802.

[0022] When using the connection and sealing structure of this boron trifluoride gas shut-off valve, the operator first fixes the bottom end of the valve body 1 to the gas cylinder via a tapered thread, connecting the gas inlet at the bottom end of the valve body 1 to the boron trifluoride gas storage device. When it is necessary to discharge boron trifluoride gas, the operator can rotate the handwheel 5 counterclockwise to drive the valve stem 4 to rotate and lift inside the pressure sleeve 3, thereby driving the valve core rod 801 to move vertically upward, thus releasing the blockage of the through groove 17 by the pad 804, and facilitating the discharge of gas through the gas outlet on the side wall of the valve body 1. When the sealing structure of the shut-off valve ages and affects its sealing performance after long-term use, after ensuring that the internal gas is emptied, the operator can rotate the pressure cap 2 clockwise to separate the valve body 1 and the pressure cap 2, and then rotate the pressure sleeve 3 counterclockwise, so as to facilitate the extraction of the pressure sleeve 3, valve core rod 801 and valve seat 802 from the inside of the valve body 1 in sequence, thereby improving the convenience of disassembly and maintenance of the shut-off valve and thus extending the service life of the shut-off valve.

[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A connection sealing structure for a boron trifluoride gas shut-off valve, characterized in that, The valve body (1) is threaded to the top of the valve body (1), a pressure cap (2) is threaded to the middle of the pressure cap (2), a pressure sleeve (3) is threaded to the outer side of the pressure sleeve (3), a valve stem (4) is threaded to the middle, a valve core assembly (8) is provided at the bottom of the valve stem (4), the valve core assembly (8) includes a valve core rod (801) rotatably connected to the bottom of the valve stem (4), a valve seat (802) is fixed at the bottom of the valve core rod (801), a pressure flange (9) is sleeved on the outer surface of the valve core rod (801), a first sealing gasket (10) is sleeved at the bottom of the valve core rod (801) near the pressure flange (9), a gasket (11) is threaded to the bottom of the first sealing gasket (10), a sealing seat (7) is threaded to the inner bottom of the valve body (1), a second sealing gasket (12) is sleeved at the bottom of the sealing seat (7), and a through groove (17) is opened in the middle of the sealing seat (7).

2. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 1, characterized in that: A connecting block (803) is fixedly provided at the top of the valve core rod (801), and the connecting block (803) is rotatably connected to the middle of the lower end of the valve core rod (4).

3. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 1, characterized in that: A pad (804) is snapped into the bottom end of the valve seat (802), and the bottom end of the pad (804) is supported on the top of the sealing seat (7).

4. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 1, characterized in that: A plug cap (6) is threaded onto the side wall of the valve body (1), and a third sealing gasket (13) is snapped onto the inner side wall of the plug cap (6).

5. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 1, characterized in that: The valve body (1) has a threaded groove (15) in the middle, which is used for the positive thread connection of the pressure sleeve (3). The pressure cap (2) is fitted on the top of the pressure sleeve (3), and the top of the valve stem (4) passes through the pressure sleeve (3).

6. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 5, characterized in that: A handwheel (5) is fixed at the top of the pressure sleeve (3), and an anti-slip groove is provided on the side wall of the handwheel (5).

7. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 6, characterized in that: The flange (9), the first sealing gasket (10) and the gasket (11) are adapted to the internal dimensions of the valve body (1), and the top of the gasket (11) is snapped into the bottom of the first sealing gasket (10).

8. The connection sealing structure of the boron trifluoride gas shut-off valve according to claim 1, characterized in that: An overlay sleeve (16) is fitted onto the inner wall of the valve body (1) near the sealing seat (7), and the overlay sleeve (16) is fitted onto the outer surface of the valve seat (802).

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