A check valve with reliable sealing under low differential pressure

Abstract

This invention discloses a check valve with reliable sealing under low differential pressure. The valve seat and valve sealing surfaces are conical, with an O-ring seal between them. The valve fits onto the valve seat, which serves as a guide. A spring is placed between the spring seat and the valve; the compressed spring presses the sealing ring against the valve, maintaining a seal. The top surfaces of the valve seat and spring seat are flush, with the spring seat restricting the valve seat's movement within its own space. When the medium flows in the forward direction, the static pressure of the medium pushes the valve against the spring force, opening the valve and allowing the medium to flow through the gap between the valve and valve seat and the guide hole. When the medium is closed or flows in the reverse direction, the valve resets under the spring's return force and the medium's static pressure, keeping the valve closed. This valve has an axial structure, resulting in low local resistance loss. The conical sealing surface, lightweight valve design, low opening pressure, and conical sealing provide a clever and reliable low differential pressure seal.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a check valve with reliable sealing under low differential pressure. Background Technology

[0002] Flame cleaning machines utilize gas flames to remove defects such as oxide scale, cracks, pitting, pits, inclusions, and bubbles from the surface of continuously cast billets, making them crucial equipment for improving product quality. Furthermore, flame cleaning machines enable "hot cleaning and hot delivery" of continuously cast billets, achieving energy savings and meeting the needs of green and low-carbon development. With the transformation of the steel industry's product structure and breakthroughs in the localization of flame cleaning machines, their application has developed rapidly.

[0003] In the development and application of flame cleaning machines, we found that precise control of gas and oxygen pressure is paramount. Taking gas regulation control as an example, the PLC outputs a 4-20mA analog signal. An I / P converter converts the electrical signal into a 3-27PSIG pressure signal, which is then amplified proportionally (1:3, 1:4) by a pressure amplifier. The control gas source then drives the regulating valve to adjust the pressure. The control gas source is nitrogen or oil-free air. To prevent gas leakage through the control gas source pipe, a check valve must be installed. Gas leakage is a major safety hazard, requiring the check valve to have excellent sealing performance.

[0004] Furthermore, during the use of the flame cleaner, the minimum operating pressure between the gas and oxygen (pressure reducing valve pressure ratio 1:1) is 0.02 bar, which also requires the check valve to open under slight pressure difference conditions.

[0005] Conventional check valves often struggle to balance low pressure differentials with good sealing performance. Under such low pressure differential operating conditions, conventional check valves frequently experience sealing surface leakage problems, such as uneven sealing surfaces due to grinding, failure to create a sealing line; sealing surface detachment; bent or misaligned valve stem causing the shut-off part to tilt; and the valve stem and shut-off part joint being suspended in the air, misaligned, or damaged.

[0006] Therefore, it is particularly important to develop a check valve with reliable micro-pressure differential sealing. Summary of the Invention

[0007] To address the problems in related technologies, this invention discloses a check valve with reliable sealing under low pressure differential, which solves the problem that conventional check valves in the background technology have difficulty in simultaneously achieving low pressure differential and good sealing performance.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A low-pressure differential sealing check valve includes a housing with a medium inlet and a medium outlet. A valve seat is fixedly installed inside the housing at the medium inlet, communicating with an external flowing medium. A valve is located at the lower part of the valve seat and is fitted inside the valve seat. The valve can move up and down under medium pressure. A spring is located at the lower end of the valve, and a spring seat is located outside the spring, fitted inside the housing and communicating with the medium outlet. Multiple first guide holes are evenly distributed on the valve. The lower part of the valve seat... The valve is provided with a plurality of second guide holes and a plurality of third guide holes. The first guide hole moves up and down with the valve and can communicate with or close with the second guide hole. The second guide hole and the third guide hole are connected. The valve has a first sealing surface on its outer side and a second sealing surface that matches the first sealing surface on its inner side. The first sealing surface and the second sealing surface are conical in shape. A first sealing ring is provided between the first sealing surface and the second sealing surface. When the check valve is closed, the first sealing surface and the second sealing surface are located between the first guide hole and the second guide hole.

[0010] As a further aspect of the present invention: the valve has a medium inlet near the medium inflow end, the valve is a hollow column with one end closed, and the first guide hole is provided on both sides of the valve body.

[0011] As a further aspect of the present invention: the extension lines of the first sealing surface and the second sealing surface are intersecting.

[0012] As a further aspect of the present invention: the valve seat is provided with a guide cavity, the valve moves up and down along the guide cavity, the outer side of the first sealing surface is provided with a guide surface, the guide surface is in vertical guiding contact with the inner side of the valve seat, the guide cavity is deviated from the outer side of the valve by less than 1 mm, and the guide surface is deviated from the inner side of the valve seat by less than 1 mm.

[0013] As a further aspect of the present invention: the total cross-sectional area of ​​the plurality of first guide holes is greater than 1.15 times the pipe diameter, the total cross-sectional area of ​​the plurality of second guide holes is greater than 1.15 times the pipe diameter, and the total cross-sectional area of ​​the plurality of third guide holes is greater than 1.15 times the pipe diameter.

[0014] As a further aspect of the present invention: the valve seat and the housing are fastened together by matching threads, and a sealing ring and a gasket are provided between the valve seat and the housing for sealing connection.

[0015] As a further aspect of the present invention: the spring seat and the housing are fastened together by matching threads, and a sealing ring and a washer are provided between the spring seat and the housing for sealing connection.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The outer side of the valve is provided with a first sealing surface, and the inner side of the valve seat is provided with a second sealing surface that matches the first sealing surface. The first sealing surface and the second sealing surface are conical in shape. A first sealing ring is provided between the first sealing surface and the second sealing surface. When the check valve is closed, the first sealing surface and the second sealing surface are located between the first guide hole and the second guide hole. The sealing surface adopts a conical area sealing ring matching scheme to avoid unevenness of the sealing surface due to grinding, and to prevent problems such as failure of sealing line and sealing surface detachment, thereby improving the sealing performance of the check valve.

[0018] 2. The valve has a medium inlet near the medium inflow end. The valve is a hollow cylindrical shape with one end closed. The first guide hole is set on both sides of the valve body. The lightweight design, such as the hollow cylindrical sink hole in the center of the valve and the guide hole, effectively reduces the weight of the valve. The check valve has a sensitive micro-pressure difference opening capability.

[0019] 3. The valve seat has a guide cavity inside, and the valve moves up and down along the guide cavity. The outer side of the first sealing surface has a guide surface, which makes up-down guiding contact with the inner side of the valve seat. The deviation between the guide cavity and the outer side of the valve is less than 1 mm, and the deviation between the guide surface and the inner side of the valve seat is less than 1 mm. The check valve adopts an axial design, with the valve head and tail respectively fitted into the two steps of the valve seat, providing double guidance. The deviation is controlled within 1 mm, which greatly reduces the impact of deviation on sealing performance and improves the sealing performance of the check valve.

[0020] 4. The total cross-sectional area of ​​the first, second, and third guide holes is 1.15 times larger than the pipe diameter. The ample flow space can ensure the flow capacity and reduce local resistance loss, thereby improving the micro-pressure differential sensitivity and sealing performance of the check valve.

[0021] In summary, this new type of check valve has high sealing performance and low differential pressure sensitivity, while also taking into account the low differential pressure and sealing performance of the check valve. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0023] In the attached diagram:

[0024] Figure 1 This is a schematic diagram of the structure of a check valve with reliable micro-differential pressure sealing according to the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of a check valve seat with reliable micro-differential pressure sealing according to the present invention.

[0026] Figure 3This is a schematic diagram of the structure of a check valve with reliable micro-pressure differential sealing according to the present invention.

[0027] Figure 4 This is a schematic diagram of the structure of a check valve spring seat with reliable micro-pressure differential sealing according to the present invention.

[0028] Attached drawing annotations: Requires the above-mentioned structure in CAD 2016 electronic format.

[0029] 01. Housing; 02. Medium inlet end; 03. Medium outlet end; 10. Valve; 11. Medium inlet; 12. First guide hole; 13. First sealing surface; 14. Guide surface; 20. Valve seat; 21. Guide cavity; 22. Second sealing surface; 23. Second guide hole; 24. First sealing ring; 30. Spring seat; 31. Spring; 32. Third guide hole; Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects disclosed in this embodiment as detailed in the appended claims.

[0031] It should be noted that all directional indicators in the embodiments (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0032] Furthermore, descriptions using terms such as "first" and "second" in the embodiments are for descriptive purposes only and do not specifically refer to any order or sequence, nor are they intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination does not exist and is not within the scope of protection claimed by this invention.

[0033] To further understand the content, features, and effects of this invention, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0034] like Figure 1-4 As shown:

[0035] The check valve with reliable micro-pressure differential sealing has an axial structure and includes a housing 01. The housing 01 includes a medium inlet end 02 and a medium outlet end 03. The medium flows into the medium inlet end 02 and out of the medium outlet end 03, but the reverse is not possible.

[0036] Inside the housing 01, a valve seat 20 is fixedly provided at the medium inflow end 02. The valve seat 20 is connected to the external flowing medium at the medium inflow end 02. A valve 10 is provided at the lower part of the valve seat 20. The valve 10 is sleeved inside the valve seat 20. The valve 10 can move up and down under the action of medium pressure. A spring 31 is provided at the lower end of the valve 10. A spring seat 30 is provided outside the spring 31. The spring seat 30 is sleeved inside the housing 01 and is connected to the medium outflow end 03.

[0037] The valve 10 is provided with a plurality of first guide holes 12 evenly distributed on the valve, the valve seat 20 is provided with a plurality of second guide holes 23 evenly distributed on the lower part of the valve, and the spring seat 30 is provided with a plurality of third guide holes 32 evenly distributed on the spring seat 30. The first guide holes 12 can communicate with or close the second guide holes 23 as the valve 10 moves up and down. The second guide holes 23 are connected to the third guide holes 32.

[0038] The medium flows in from the medium inlet end 02, passes through the valve seat 20, and reaches the valve 10. The valve 10 moves under the pressure of the flowing medium, compressing the spring 31. The first guide hole 12 and the second guide hole 23 connect, and the medium passes through the first guide hole 12, the second guide hole 23, and the third guide hole 32, then flows out from the medium outlet end 03 through the spring seat 30. When no medium flows through, the valve 10 resets under the elastic force of the spring 31, thus closing.

[0039] When the medium flows in the reverse direction, valve 10 is in the closed position and cannot flow.

[0040] Preferably, the outer side of the valve 10 is provided with a first sealing surface 13, and the inner side of the valve seat 20 is provided with a second sealing surface 22 that matches the first sealing surface 13. The first sealing surface 13 and the second sealing surface 22 are conical in shape.

[0041] A first sealing ring 24 is provided between the first sealing surface 13 and the second sealing surface 22. When the check valve is closed, the first sealing surface 13 and the second sealing surface 22 are located between the first guide hole 12 and the second guide hole 23 to achieve the closing function.

[0042] The valve 10 has a medium inlet 11 near the medium inflow end 02. The valve 10 is a hollow column with one end closed. The first guide hole 12 is located on both sides of the valve 10 body.

[0043] The extended lines of the first sealing surface 13 and the second sealing surface 22 intersect. The rubber-set first sealing surface 13 and the second sealing surface 22 form a triangular sealing area with the inner side of the valve seat 20. A first sealing ring 24 is provided in the sealing area. The first sealing ring 24 is in sealing contact with all three surfaces. The multi-point sealing contact improves the sealing performance of the check valve.

[0044] The valve seat 20 has a guide cavity 21 inside. The valve 10 moves up and down along the guide cavity 21. The outer side of the first sealing surface 13 has a guide surface 14. The guide surface 14 is in vertical guide contact with the inner side of the valve seat 20. The deviation between the guide cavity 21 and the outer side of the valve 10 is less than 1 mm, and the deviation between the guide surface 14 and the inner side of the valve seat 20 is less than 1 mm.

[0045] The total cross-sectional area of ​​the multiple first guide holes 12 is greater than 1.15 times the pipe diameter, the total cross-sectional area of ​​the multiple second guide holes 23 is greater than 1.15 times the pipe diameter, and the total cross-sectional area of ​​the multiple third guide holes 32 is greater than 1.15 times the pipe diameter.

[0046] The valve seat 20 is fastened to the housing 01 by matching threads, and a sealing ring and a gasket are provided between the valve seat 20 and the housing 01 for sealing connection.

[0047] The spring seat 30 and the housing 01 are fastened together by matching threads, and a sealing ring and a gasket are provided between the spring seat 30 and the housing 01 for sealing connection.

[0048] In practical applications:

[0049] The outer side of the valve 10 is provided with a first sealing surface 13, and the inner side of the valve seat 20 is provided with a second sealing surface 22 that matches the first sealing surface 13. The first sealing surface 13 and the second sealing surface 22 are conical in shape. A first sealing ring 24 is provided between the first sealing surface 13 and the second sealing surface 22. When the check valve is closed, the first sealing surface 13 and the second sealing surface 22 are located between the first guide hole 12 and the second guide hole 23. The sealing surface adopts a conical area sealing ring matching scheme to avoid unevenness of the sealing surface due to grinding, and to prevent problems such as non-sealing line and sealing surface detachment, thereby improving the sealing performance of the check valve.

[0050] The valve 10 has a medium inlet 11 near the medium inflow end 02. The valve 10 is a hollow cylindrical shape closed at one end. The first guide hole 12 is located on both sides of the valve 10 body. The lightweight design, including the hollow cylindrical center countersunk hole and the guide holes, effectively reduces the weight of the valve 10. In addition, reducing the surface roughness of the valve seat 20 and the valve 10 during processing can also effectively reduce the movement resistance of the valve 10. The check valve has a sensitive micro-pressure differential opening capability.

[0051] The valve seat 20 has a guide cavity 21 inside, and the valve 10 moves up and down along the guide cavity 21. The outer side of the first sealing surface 13 has a guide surface 14, which makes up-down guiding contact with the inner side of the valve seat 20. The deviation between the guide cavity 21 and the outer side of the valve 10 is less than 1 mm, and the deviation between the guide surface 14 and the inner side of the valve seat 20 is less than 1 mm. The check valve adopts an axial design, with the head and tail of the valve 10 respectively fitted into the two steps of the valve seat 20, providing double guidance. The deviation is controlled within 1 mm, which greatly reduces the impact of deviation on sealing performance and improves the sealing performance of the check valve.

[0052] The total cross-sectional area of ​​the first guide hole 12, the second guide hole 23, and the third guide hole 32 is 1.15 times larger than the pipe diameter. The ample flow space can ensure the flow capacity and reduce local resistance loss, thereby improving the micro-pressure differential sensitivity and sealing performance of the check valve.

[0053] In summary, this new type of check valve has high sealing performance and low differential pressure sensitivity, while also taking into account the low differential pressure and sealing performance of the check valve.

[0054] Finally, it should be noted that the above disclosure is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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. The scope of this application is limited only by the appended claims.

Claims

1. A check valve with reliable micro-differential pressure sealing, comprising a housing (01), the housing (01) including a medium inlet end (02) and a medium outlet end (03), characterized in that: Inside the housing (01), a valve seat (20) is fixedly provided at the medium inflow end (02). The valve seat (20) is connected to the external flowing medium at the medium inflow end (02). A valve (10) is provided at the lower part of the valve seat (20). The valve (10) is sleeved inside the valve seat (20). The valve (10) can move up and down under the action of medium pressure. A spring (31) is provided at the lower end of the valve (10). A spring seat (30) is provided outside the spring (31). The spring seat (30) is sleeved inside the housing (01). The spring seat (30) is connected to the medium outflow end (03). A plurality of first guide holes (12) are evenly provided on the valve (10). A plurality of second guide holes (23) are evenly provided at the lower part of the valve seat (20). (30) is uniformly provided with a plurality of third guide holes (32). The first guide hole (12) moves up and down with the valve (10) and can communicate with or close the second guide hole (23). The second guide hole (23) is connected to the third guide hole (32). The outer side of the valve (10) is provided with a first sealing surface (13). The inner side of the valve seat (20) is provided with a second sealing surface (22) that matches the first sealing surface (13). The first sealing surface (13) and the second sealing surface (22) are conical. A first sealing ring (24) is provided between the first sealing surface (13) and the second sealing surface (22). When the check valve is closed, the first sealing surface (13) and the second sealing surface (22) are located between the first guide hole (12) and the second guide hole (23).

2. The check valve with reliable micro-differential pressure sealing according to claim 1, characterized in that: The valve (10) has a medium inlet (11) near the medium inflow end (02). The valve (10) is a hollow column with one end closed. The first guide hole (12) is located on both sides of the valve (10) body.

3. The check valve with reliable micro-pressure differential sealing according to claim 1, characterized in that: The extended lines of the first sealing surface (13) and the second sealing surface (22) are intersecting.

4. The check valve with reliable micro-differential pressure sealing according to claim 1, characterized in that: The valve seat (20) is provided with a guide cavity (21) inside. The valve (10) moves up and down along the guide cavity (21). The first sealing surface (13) is provided with a guide surface (14) on the outside. The guide surface (14) is in vertical guiding contact with the inner side of the valve seat (20). The deviation between the guide cavity (21) and the outer side of the valve (10) is less than 1 mm. The deviation between the guide surface (14) and the inner side of the valve seat (20) is less than 1 mm.

5. A check valve with reliable micro-differential pressure sealing according to claim 1, characterized in that: The total cross-sectional area of ​​the plurality of first guide holes (12) is greater than 1.15 times the pipe diameter, the total cross-sectional area of ​​the plurality of second guide holes (23) is greater than 1.15 times the pipe diameter, and the total cross-sectional area of ​​the plurality of third guide holes (32) is greater than 1.15 times the pipe diameter.

6. The check valve with reliable micro-differential pressure sealing according to claim 1, characterized in that: The valve seat (20) and the housing (01) are fastened together by matching threads, and a sealing ring and a gasket are provided between the valve seat (20) and the housing (01) for sealing connection.

7. The check valve with reliable micro-differential pressure sealing according to claim 1, characterized in that: The spring seat (30) and the housing (01) are fastened together by matching threads, and a sealing ring and a gasket are provided between the spring seat (30) and the housing (01) for sealing connection.

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