Micro-pressure zero-leakage check valve

Abstract

The micro-pressure zero-leakage check valve comprises a valve body, a valve clack, a spring, a guide sleeve, an O-shaped ring and a sealing gasket, a valve rod at the rear end of the valve clack penetrates through a guide sleeve hole to form first-time guiding, a second guide sleeve at the rear end of the valve clack is connected to the first guide sleeve in a sleeving mode to slide left and right to form second-time guiding, and a valve rod at the rear end of the valve clack penetrates through the O-shaped ring to form second-time guiding. The front end of the valve clack forms third guide through a third guide sleeve located on the valve body, the axis of the valve clack is highly overlapped with the axis of the valve body in the valve body through triple guide, sliding friction force is minimum, and ultra-micro-pressure opening is achieved; when the check valve is opened, the valve clack moves rightwards along the axis of the valve body and is separated from the third guide sleeve; when the check valve is closed, the spring located on the valve rod overcomes the sliding friction resistance of the valve clack, pushes the valve clack to move in the direction opposite to the medium flowing direction and reaches the sealing position under the guide of the third guide sleeve, and the check valve can be closed under the condition of no back pressure or extremely low back pressure, and zero leakage of gas sealing is achieved.

Description

Technical Field

[0001] The invention relates to an ultra-micro pressure check valve, in particular to an ultra-micro pressure zero leakage check valve. Background Art

[0002] Existing various check valve structures such as swing, lift, butterfly, inclined flap, axial flow and other structures are difficult to open normally under ultra-low pressure (500 Pa-3000 Pa), and cannot be closed and achieve zero gas leakage under no back pressure or extremely low back pressure. Mainly, some other check valves cannot be opened due to heavy valve discs, and some have large opening resistance due to insufficient coaxiality, and cannot be opened under ultra-low pressure (500 Pa-3000 Pa), and cannot be closed under no back pressure or extremely low back pressure, low pressure difference and achieve zero gas leakage.

[0003] In actual production, high-end biopharmaceuticals, refining, coal chemical industry, fine chemical industry and other projects have real needs, and urgently need a check valve to solve the problem of opening under ultra-low pressure, low pressure difference and zero leakage of gas sealing. Summary of the invention

[0004] Therefore, the present invention aims to solve the problem that the existing check valve structure cannot open normally under ultra-low pressure (500 Pa-3000 Pa), and cannot close under no back pressure or extremely low back pressure, low pressure difference and achieve zero leakage of gas sealing.

[0005] The technical solution of the present invention to realize ultra-low pressure opening and gas sealing zero leakage under no back pressure or extremely low back pressure conditions is a triple-guided check valve structure, including: 1-valve body; 2-O-ring; 3-valve disc; 4-second guide sleeve; 5-first guide sleeve; 6-O-ring; 7-sealing gasket; 8-valve stem; 9-spring; 10-third guide sleeve; 11-guide sleeve thread; 12-valve body thread. The valve disc 3, spring 9, and first guide sleeve 5 are installed in the valve body 1 of the above-mentioned micro-pressure zero leakage check valve in sequence from left to right along the flow direction of the medium. The spring 9 is installed on the valve stem 8, and the guide sleeve thread 11 is screwed into the valve body thread 12 and fixed on the valve body 1. The valve disc 3 is integrally sleeved on the guide sleeve 5 through the second guide sleeve 4. The inner diameter of the second guide sleeve 4 is slightly larger than the outer diameter of the first guide sleeve 5, so that the valve disc 3 can slide left and right along the outer diameter of the first guide sleeve 5 as a whole. When the medium enters from the left side of the valve body 1, the valve disc 3 is pushed to move right as a whole, and the valve stem 8 moves along the axis in the inner hole of the first guide sleeve 5. At this time, under the guidance of the outer diameter of the first guide sleeve 5, the valve disc 3 moves axially along the valve body 1 as a whole, and the check valve opens; when the medium pressure is lower than the elastic force of the spring 9, the spring 9 pushes the valve disc 3 to move in the direction opposite to the medium flow direction, and finally reaches the third guide sleeve 10. Under the guidance of the valve stem 8, the first guide sleeve 5, the second guide sleeve 4, and the third guide sleeve 10, the axis of the valve disc 3 coincides with the axis of the valve body 1, and correctly reaches the sealing position to complete the closing action. The valve stem 8 is installed in the circular hole of the first guide sleeve 5 to guide the valve disc 3 for the first time, and the second guide sleeve 4 is sleeved on the first guide sleeve 5 to guide the valve disc 3 for the second time. The valve disc 3 is guided for the third time by the conical guide surface of the third guide sleeve 10, so that the valve disc 3 moves in parallel inside the valve body, and at the same time, the valve disc 3 and the valve body 1 are completely concentric. When the valve disc 3 and the valve body 1 are completely concentric, the parts of the guide surfaces that contact each other are precisely machined and polished to make the sliding friction resistance extremely low. The valve disc 3 has almost no friction resistance during the movement, so it can move freely under ultra-low opening pressure, thereby realizing opening under ultra-low pressure; when closing, the spring 9 overcomes the sliding friction resistance of the valve disc 3, pushes the valve disc 3 to move in the direction opposite to the medium flow direction, and reaches the third guide sleeve 10. When the check valve is closed, even if there is no medium pressure, the spring can push the valve disc 3 to reach the sealing position, so it can be closed without back pressure or under extremely low back pressure and achieve zero leakage of gas sealing.

[0006] Preferably, the first guide sleeve 5 is installed with an O-ring 6 and a sealing gasket 7. The sealing gasket 7 and the O-ring 6 are mainly used to achieve the sealing of the medium inside the valve body. If one of the sealing gasket 7 and the O-ring 6 is damaged during installation or use, the other seal can still achieve zero leakage of the internal seal, and the two seals complement each other.

[0007] Preferably, the valve flap 3 is installed with an O-ring 2. When the check valve is closed, the sealing surface cannot fit tightly due to the extremely low closing pressure. The O-ring 2 can perform auxiliary sealing under extremely low closing pressure, so that the gas seal achieves zero leakage.

[0008] Preferably, the valve stem 8 is installed with a spring 9. When the check valve is closed, the spring 9 can overcome the friction resistance of the valve flap 3, so that the valve flap 3 can reach the sealing position in the absence of medium pressure, thereby realizing the closing action of the check valve.

[0009] Preferably, the first guide sleeve 5 is drilled with a round hole, and the valve stem 8 is installed in the round hole of the first guide sleeve 5. The round hole can limit and guide the valve stem 8 so that the valve stem 8 can only move along a fixed direction, thereby achieving the first guidance of the valve disc 3.

[0010] Preferably, the second guide sleeve 4 is sleeved on the first guide sleeve 5, and the inner diameter of the second guide sleeve 4 is slightly larger than the outer diameter of the first guide sleeve 5, so that the valve flap 3 together with the second guide sleeve 4 can slide freely on the first guide sleeve 5 to form a second guide.

[0011] Preferably, the valve flap 3 is installed on the third guide sleeve 10. The check valve is in a closed state when there is no medium pressure. The third guide sleeve 10 mainly guides the valve flap 3 to reach the correct sealing position. The valve flap 3 is guided for the third time so that the axis of the valve flap 3 coincides with the axis of the valve body 1. When the sealing surfaces are completely matched, a zero-leakage effect of gas sealing is achieved.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] Through the innovative design of the internal structure, the valve disc guide has been innovated. Through the triple guide positioning, the valve disc and the valve body are highly concentric, with almost no sliding friction resistance, and can be opened under ultra-low pressure and achieve zero gas sealing leakage under no back pressure conditions. The fact that it can be opened under ultra-low pressure shows that the internal flow resistance of this micro-pressure zero leakage check valve is extremely low, and the pressure difference before and after the valve is extremely small (pressure loss), which mainly achieves the three important technical indicators of micro-pressure opening, low pressure difference and zero gas sealing leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific implementation methods and technical solutions of the present invention, the present invention is further described below in combination with the accompanying drawings and specific implementation methods. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 Schematic diagram of the present invention

[0016] Figure 2 For along Figure 1 Internal structure cross section of line AA

[0017] Description of reference numerals:

[0018] 1-valve body; 2-O-ring; 3-valve disc; 4-second guide sleeve; 5-first guide sleeve; 6-O-ring; 7-sealing gasket; 8-valve stem; 9-spring; 10-third guide sleeve; 11-guide sleeve thread; 12-valve body thread. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention, and any improvements and local changes made using the ideas of the present invention will be included in the scope of protection of the present invention.

[0020] In the description of the present invention, it should be noted that the terms "axis", "center line", "horizontal", "parallel", "left and right", "left", "first", "second", "third" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0021] like Figure 1 and Figure 2 The present embodiment provides a micro-pressure zero-leakage check valve, comprising: 1-valve body; 2-O-ring; 3-valve disc; 4-second guide sleeve; 5-first guide sleeve; 6-O-ring; 7-sealing gasket; 8-valve stem; 9-spring; 10-third guide sleeve; 11-guide sleeve thread; 12-valve body thread.

[0022] An O-ring 2 is installed at the front end of the valve disc 3 to assist in sealing.

[0023] Optionally, the material of the valve disc 3 can be selected from stainless steel, high-temperature steel, special materials, etc. according to actual working conditions such as temperature, pressure, corrosiveness, etc.; the O-ring 2 can be used or cancelled according to temperature conditions; when the temperature is lower than 300°C, the material of the O-ring 2 is selected from VITON or FFKM, and when the temperature is higher than 300°C, the O-ring 2 is cancelled.

[0024] A spring 9 is sleeved on the valve stem 8, and the guide sleeve thread 11 is screwed into the valve body thread 12 and fixed on the valve body 1. Optionally, the elastic force of the spring 9 can be preset, and the preset value of the elastic force is: less than the pressure of the positive inflow medium to ensure that the check valve can open normally. Since the positive opening pressure value may fluctuate, the spring elastic force is less than the minimum value when the positive pressure fluctuates. According to the corrosiveness of the medium, the spring material can be selected from stainless steel, nickel-based alloy, titanium alloy, chrome-silicon alloy, composite spring, etc. The selection principle is that the physical properties of the spring cannot be changed by the medium temperature, corrosiveness, etc. When the physical properties of the spring change, the opening and closing performance of the check valve will be greatly affected, and it may even fail to work normally.

[0025] The first guide sleeve 5 is provided with a sealing gasket 7 and an O-ring 6 for internal sealing to prevent the medium from leaking to the outside of the valve body through the gap between the guide sleeve and the valve body.

[0026] Optionally, the sealing gasket 7 and O-ring 6 installed on the first guide sleeve 5 can change the material according to the change of temperature conditions. When the temperature is lower than 300°C, RPTFE, VITON or FFKM can be selected; when the temperature is higher than 300°C, Flexible graphite or metal graphite can be selected.

[0027] The first guide sleeve 5 is drilled with a round hole, and the valve stem 8 is installed in the round hole of the first guide sleeve 5. The round hole can limit and guide the valve stem 8, so that the valve stem 8 can only move along a fixed direction, thereby realizing the first guidance of the valve disc 3. The second guide sleeve 4 is sleeved on the first guide sleeve 5 to guide the valve disc 3 for the second time, ensuring that the valve disc 3 moves left and right along the axis of the valve body 1. When the valve disc 3 moves to the left to the third guide sleeve 10, the third guide sleeve 10 guides the valve disc 3 for the third time. At this time, the valve disc 3 is completely parallel to the valve body inside the valve body 1 and highly coincides with the center line of the valve body. The valve disc 3 is in the valve body 1. There is almost no friction resistance when the inside moves left and right, and the medium does not need to overcome the friction resistance of the valve disc 3 to smoothly push the valve disc 3 to move. It can be opened normally under ultra-low pressure (500 Pa-3000 Pa). The fact that it can be opened under ultra-low pressure shows that the internal flow resistance of the micro-pressure zero leakage check valve is extremely low, and the pressure difference before and after the valve is extremely small (pressure loss); when the check valve is closed, the spring 9 can overcome the friction resistance of the valve disc 3, so that the valve disc 3 can reach the sealing position even in the absence of medium pressure, thereby realizing the closing action of the check valve, closing without back pressure or under extremely low back pressure and achieving gas sealing with zero leakage.

[0028] Optionally, when the temperature is higher than 300°C, since the O-ring 2 at the front end of the valve disc 3 is removed, there is no O-ring 2 to assist in sealing. The sealing surface of the third guide sleeve 10 and the sealing surface at the front end of the valve disc 3 need to be precisely ground and matched to ensure zero gas sealing when metal sealing is used.

[0029] The overall structure of the micro-pressure zero leakage check valve is convenient for disassembly, assembly, replacement and maintenance of the guide sleeve, sealing ring, sealing gasket, spring and valve disc.

[0030] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. The present invention mainly realizes three important technical indicators: micro-pressure opening, low pressure difference and gas sealing zero leakage. The present invention is not limited to the above-described embodiments. For those skilled in the art, various changes, modifications, substitutions and deformations of these embodiments without departing from the principles and ideas of the present invention should still fall within the scope of protection of the present invention.

Claims

1. A micro-pressure zero leakage check valve, characterized in that: include: A valve body (1), an O-ring (2), a valve disc (3), a second guide sleeve (4), a first guide sleeve (5), an O-ring (6), a sealing gasket (7), a valve stem (8), a spring (9), a third guide sleeve (10), a guide sleeve thread (11), and a valve body thread (12). The valve disc (3), the spring (9), and the first guide sleeve (5) are sequentially installed in the valve body (1) from left to right along the flow direction of the medium. The guide sleeve thread (11) is screwed into the valve body thread (12) and fixed on the valve body (1); When the micro-pressure zero-leakage check valve is opened, the valve flap (3) moves to the right along the axis of the valve body (1) and disengages from the third guide sleeve (10), and the check valve opens; when the check valve is closed, the spring (9) pushes the valve flap (3) to move to the left and reach the third guide sleeve (10), so that the sealing surface of the valve flap (3) and the sealing surface of the third guide sleeve (10) are combined to form a seal.

2. The micro-pressure zero-leakage check valve according to claim 1, characterized in that: The first guide sleeve (5) is installed with an O-ring (6) and a sealing gasket (7). The sealing gasket (7) and the O-ring (6) are mainly used to seal the medium inside the valve body. If one of the sealing gasket (7) and the O-ring (6) is damaged during installation or use, the other seal can still achieve zero leakage of the internal seal. The two seals complement each other.

3. The micro-pressure zero-leakage check valve according to claim 1, characterized in that: The valve flap (3) is installed with an O-ring (2). When the check valve is closed, the sealing surface cannot fit tightly due to the extremely low closing pressure. The O-ring (2) can perform auxiliary sealing under the extremely low closing pressure, so that the gas seal achieves zero leakage.

4. The micro-pressure zero-leakage check valve according to claim 3 is characterized in that: The valve stem (8) is provided with a spring (9). When the check valve is closed, the spring (9) can overcome the friction resistance of the valve flap (3), so that the valve flap (3) can reach the sealing position even in the absence of medium pressure, thereby realizing the closing action of the check valve.

5. The micro-pressure zero-leakage check valve according to claim 1, characterized in that: The first guide sleeve (5) is drilled with a circular hole, and the valve stem (8) is installed in the circular hole of the first guide sleeve (5). The circular hole can limit and guide the valve stem (8), so that the valve stem (8) can only move along a fixed direction, thereby forming a first guide for the valve flap (3).

6. The micro-pressure zero-leakage check valve according to claim 1, characterized in that: The second guide sleeve (4) is sleeved on the first guide sleeve (5), and the inner diameter of the second guide sleeve (4) is slightly larger than the outer diameter of the first guide sleeve (5), so that the second guide sleeve (4) can slide freely on the first guide sleeve (5) to form a second guide for the valve disc (3).

7. The micro-pressure zero-leakage check valve according to claim 1, characterized in that: The valve flap (3) is mounted on the third guide sleeve (10). The check valve is in a closed state when there is no medium pressure. The third guide sleeve (10) mainly guides the valve flap (3) to a correct sealing position and guides the valve flap (3) for a third time so that the axis of the valve flap (3) coincides with the axis of the valve body (1). When the sealing surfaces are completely aligned, a gas sealing zero leakage effect is achieved.

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