Deep sea sampling cock valve

Abstract

This invention discloses a deep-sea sampling plug valve, specifically relating to the field of plug valves. It includes a valve body with a removable gland at one end, forming a hollow cylindrical structure with one end closed and the other open. Two ports, Port 1 and Port 2, are respectively located on opposite outer sides of the valve body. A valve sleeve 1 and a valve sleeve 2, distributed axially, are embedded inside the valve body, forming a cavity between them. Port 1, the cavity, and Port 2 constitute a sampling passage. A valve core is located inside the valve body, movably embedded within the valve sleeve 1 and valve sleeve 2. The valve core moves axially, allowing the sampling passage to be closed or open. A nut is installed at one end of the valve core. This invention improves the sealing effect of the valve body through a structure of one valve core and two valve sleeves. The removable design facilitates inspection of the valve core before sampling. Furthermore, the sealing force between the valve core and valve sleeve 2 increases with increasing pressure difference, enhancing the reliability of the seal.

Description

Technical Field

[0001] This invention relates to the field of plug valve technology, and more specifically, to a deep-sea sampling plug valve. Background Technology

[0002] Hydrothermal vents are mostly distributed at the boundaries of active tectonic plates and in areas of intraplate volcanic activity. Since the first discovery of hydrothermal vents in 1979, scientific investigation and research on hydrothermal activity has become a shared mission for multiple disciplines, including oceanography, geology, geochemistry, mineralogy, and marine biology. Hydrothermal vents are characterized by high temperature, high pressure, and corrosiveness, posing severe challenges to the design and use of sampling equipment. The hydrothermal sampler is an electromechanical device for collecting and storing deep-sea hydrothermal vent samples. To prevent contamination of the samples and maintain their in-situ pressure, the design of its core component, the sampling valve, is extremely important. The laboratory-designed hydrothermal sampling valve, valve body, and valve sleeve are made of TC4 resin; the valve core is made of polyetheretherketone (PEEK) resin, a high-performance engineering plastic with a normal operating temperature of 260℃ and a short-term operating temperature exceeding 300℃. It also possesses high strength, good impact resistance, and corrosion resistance, meeting the design requirements. The sampling valve uses a TC4-PEEK combination to achieve pressure sealing, with a maximum working pressure requirement of 70 MPa.

[0003] Under such high pressure, PEEK valve cores are prone to fatigue failure after repeated use. The grooves of the valve core break after being subjected to large tensile stress, affecting the internal seal of the sampling valve, causing the sampling valve to malfunction and the hydrothermal sampler to fail to collect samples. Summary of the Invention

[0004] The present invention provides a deep-sea sampling plug valve, which aims to solve the problem that existing plug valves are prone to sample leakage or seawater seepage into the sample and contamination under the high pressure environment of deep sea.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a deep-sea sampling plug valve, comprising a valve body, one end of which is fitted with a detachable pressure cap, the valve body and the pressure cap forming a hollow cylindrical structure with one end closed and the other end open, two ports respectively opened on opposite outer sides of the valve body, valve sleeve one and valve sleeve two axially distributed inside the valve body, and a cavity formed between valve sleeve one and valve sleeve two, port one, cavity and port two forming a sampling passage, valve core inside the valve body, valve core movably embedded in valve sleeve one and valve sleeve two, valve core moving axially to close or open the sampling passage, nut installed at one end of valve core, a driving device provided on the side of the nut away from the valve core, the output end of the nut pressing against the nut, elastic element inside the pressure cap, the two ends of the elastic element being connected to the nut and the inner wall of the pressure cap respectively.

[0006] In a preferred embodiment, the valve core includes a shaft with a protrusion at the middle position. The joint between the protrusion and the shaft is chamfered, and the two sides of the protrusion are respectively adapted to valve sleeve one and valve sleeve two.

[0007] In a preferred embodiment, groove one and groove two are provided at the end of the shaft, and O-rings are fitted in both groove one and groove two.

[0008] In a preferred embodiment, an inner bushing is fixedly installed inside the opening end of the valve body, and the end of the shaft body is stepped with the inner bushing.

[0009] In a preferred embodiment, a protrusion is integrally formed on the end of the shaft near the inner bushing, the size of which is adapted to the inner diameter of the inner bushing.

[0010] In a preferred embodiment, the driving device is a linear screw drive device, and the driving device and the gland are threaded together.

[0011] The technical effects and advantages of this invention are as follows:

[0012] 1. This invention improves the sealing effect of the valve body by using a structure of one valve core and two valve sleeves. The detachable design facilitates inspection of the valve core before sampling. Moreover, the sealing force between the valve core and the valve sleeve increases with the increase of the pressure difference, which not only increases the reliability of the seal, but also, under the pressure of seawater, presses the left side of the gland, further increasing the sealing force at the connection between the valve body and the gland. This gives the plug valve good sealing performance under high pressure and eliminates the impact of the detachable design on the sealing performance.

[0013] 2. The present invention achieves this by forming a secondary sealing structure on the broken shaft at the moment the valve core breaks, and by combining this with the self-locking of the output shaft thread of the drive device to suppress the reverse movement of the drive device under force. The two work together to ensure that even after the valve core breaks, the sample in the cavity and sampling tube is still protected from external seawater contamination. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural schematic diagram of the plug valve of the present invention;

[0015] Figure 2 This is a frontal cross-sectional view of the plug valve of the present invention in its initial closed state;

[0016] Figure 3 This is a frontal cross-sectional view of the open state of the plug valve during sampling according to the present invention;

[0017] Figure 4 This is a front cross-sectional view of the valve core of the plug valve of the present invention breaking in the return state.

[0018] Figure 5 This is a schematic diagram of the valve core structure of the plug valve of the present invention;

[0019] Figure 6 For the present invention Figure 4 An enlarged schematic diagram of the structure at point A in the middle.

[0020] The attached figures are labeled as follows: 1. Valve body; 11. Port 1; 12. Port 2; 13. Inner bushing; 2. Gland; 21. Elastic element; 3. Valve sleeve 1; 4. Valve sleeve 2; 5. Valve core; 51. Shaft; 52. Protrusion; 53. Groove 1; 54. Groove 2; 55. Protrusion; 6. Cavity; 7. Drive device; 71. Nut; 8. Low-pressure chamber. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example

[0023] Refer to the instruction manual appendix Figures 1 to 6 A deep-sea sampling plug valve includes a valve body 1, with a detachable pressure cap 2 fitted at one end of the valve body 1. The valve body 1 and the pressure cap 2 form a hollow cylindrical structure with one end closed and the other end open. Port 11 and port 12 are respectively opened on the two opposite outer sides of the valve body 1. Valve sleeve 3 and valve sleeve 4 are embedded in the valve body 1 along the axial direction, and a cavity 6 is formed between valve sleeve 3 and valve sleeve 4. Port 11, cavity 6 and port 12 form a sampling passage. Valve core 5 is provided inside the valve body 1. Valve core 5 is movably embedded in valve sleeve 3 and valve sleeve 4. Valve core 5 moves along the axial direction to make the sampling passage closed or open. A nut 71 is installed at one end of the valve core 5. A driving device 7 is provided on the side of the nut 71 away from the valve core 5. The output end of the nut 71 presses against the nut 71. An elastic element 21 is provided inside the pressure cap 2. The two ends of the elastic element 21 are respectively connected to the nut 71 and the inner wall of the pressure cap 2.

[0024] It should be noted that the valve body 1 and the pressure cap 2 can be connected by plug-in or by thread. In practical applications, the drive device 7 uses a screw rotation to press against the nut 71. During sampling, port 11 serves as the inlet for the hydrothermal sample and port 12 serves as the outlet connected to the sample chamber. That is, port 12 is connected to the sampling tube. The elastic element 21 can be a spring or other element that can provide elasticity to ensure that the valve core 5 remains in a normally closed state.

[0025] In this embodiment, the specific implementation scenario is as follows: the plug valve operates in three processes:

[0026] Before sampling, the plug valve is normally closed. Under the action of the elastic element 21, the valve core 5 abuts against the left side of the valve sleeve 4, establishing a seal and closing the right side of the cavity 6, thereby sealing the sampling channel. Before sampling, the staff needs to disassemble the plug valve to check the appearance of the valve core 5, so as to avoid the plug valve being subjected to excessive tensile stress and broken during sampling. The detachable design of the pressure cap 2 and the valve body 1 greatly facilitates the inspection of the plug valve. After the inspection is completed, the plug valve descends into the deep sea with the sampler. Under the pressure of the seawater, it presses the left side of the pressure cap 2, further increasing the sealing force at the connection between the valve body 1 and the pressure cap 2. Moreover, the sealing force increases with the increase of seawater pressure, avoiding the reduction of the sealing effect of the plug valve due to the detachable design. At the same time, during the descent, the drive device 7 drives the nut 71 to the right, so that the valve core 5 abuts against the left side of the valve sleeve 4, establishing a seal and ensuring that the sampling channel is always closed during the descent.

[0027] During the sampling process, the sampler and the stopcock valve are in the sampling position. At this time, the pressure of the seawater is the greatest. The driving device 7 acts in the opposite direction on the nut 71, causing it to move to the left or not to move to the left. The valve core 5 abuts against the valve sleeve 3, sealing the left side of the cavity 6. Under the pressure difference between the seawater and the internal cavity 6 of the valve body 1, the valve core 5 is pushed to the left, opening the stopcock valve. The high-temperature and high-pressure molten hot liquid is drawn in from port 11 and enters the sampling tube from port 22 through the sampling channel.

[0028] After sampling is completed, the drive device 7 drives the nut 71 in the forward direction. Under the combined action of the elastic element 21 and the drive device 7, the valve core 5 re-establishes a seal with the valve sleeve 4, and the plug valve closes. During the retrieval of the sampling equipment, the plug valve rises from the seabed to the surface with the sampling equipment. The pressure of the surrounding seawater gradually decreases, while the pressure inside the sampling tube and the cavity 6 remains unchanged (the same as the pressure at the sampling position, with the internal pressure being the highest). Since the right end of the valve body 1 is in direct contact with the external seawater, the right end of the valve core 5 is subjected to tension under the action of the internal and external pressure difference, causing the valve core 5 to press further onto the valve sleeve 4. The greater the internal and external pressure difference, the greater the sealing force. Therefore, after sampling, the sealing force between the valve core 5 and the valve sleeve 4 increases with the increase of the pressure difference, increasing the reliability of the seal.

[0029] The valve core 5 includes a shaft 51, a protrusion 52 is provided at the middle position of the shaft 51, the joint between the protrusion 52 and the shaft 51 is chamfered, and the two sides of the protrusion 52 are respectively adapted to valve sleeve 3 and valve sleeve 4.

[0030] To further explain, when the right side of the protrusion 52 abuts against the left side of the valve sleeve 2 4, the plug valve is closed; when the left side of the protrusion 52 abuts against the right side of the valve sleeve 1 3, the plug valve is open.

[0031] The end of the shaft 51 is provided with a first groove 53 and a second groove 54, and an O-ring is fitted in both the first groove 53 and the second groove 54.

[0032] It should be noted that since there is a certain amount of oil in the groove 53, the valve core 5 will be more flexible when sliding in the valve body 1 due to lubrication. In addition, due to the presence of the annular groove, the friction between the valve core 5 and the valve body 1 is smaller than that without the groove, and it can also reduce the radial unbalanced force.

[0033] An inner bushing 13 is fixedly installed inside the open end of the valve body 1, and the end of the shaft 51 is stepped with the inner bushing 13.

[0034] It should be noted that when the plug valve is in the closed state, there is still a gap between the right end of the shaft 51 and the inner bushing 13. When the valve core 5 in the plug valve is subjected to large tensile stress and reaches the fatigue life, it will break along the groove 53 or groove 54 of the shaft 51.

[0035] The end of the shaft 51 near the inner bushing 13 is integrally formed with a protrusion 55, the size of which is adapted to the inner diameter of the inner bushing 13.

[0036] The drive device 7 is a linear screw drive device, and the drive device 7 and the pressure plate 2 are threadedly connected;

[0037] Furthermore, the left end of the pressure cap 2 is sealed, and the screw of the drive device 7 is threadedly engaged with the pressure cap 2. When the drive device 7 is working, the screw rotates in both directions to achieve axial movement of the screw inside the pressure cap 2, providing driving force for the nut 71 and the valve core 5.

[0038] In this embodiment, the specific implementation scenario is as follows: If, after sampling, the stopcock valve rises from the seabed to the surface along with the sampling equipment, and the right end of the valve body 1 is in direct contact with the external seawater, under the action of the internal and external pressure difference, the tensile stress on the right end of the valve core 5 gradually increases. When the right end of the valve core 5 breaks along groove 1 53 or groove 2 54, the right end of the broken shaft 51, under the combined action of tensile force and internal and external pressure difference at the moment of breakage, will cause the right end of the broken shaft 51 to abut against the left end of the inner bushing 13, and the protrusion 55 matches the inner diameter of the inner bushing 13, preventing the broken shaft 51 from... Instead of directly detaching from valve body 1, it forms a new blocking valve core. The two ends formed by the break in shaft 51 create a low-pressure chamber 8 inside valve body 1. (The pressure in this low-pressure chamber 8 is less than the pressure inside cavity 6 and the sampling tube. However, as the sampler rises to the sea surface, the pressure of the seawater on the right end of valve core 5 gradually decreases. Therefore, the pressure in low-pressure chamber 8 is greater than the pressure of the external seawater, meaning the pressure inside cavity 6 is greater than the pressure in low-pressure chamber 8, and the pressure inside low-pressure chamber 8 is greater than the pressure of the external seawater.) Under the pressure difference of low-pressure chamber 8, the protrusion 52 of valve core 5 still... The broken shaft 51 and inner bushing 13 form a sealing state, creating a double sealing structure inside the valve body 1 by allowing the broken shaft 51 to form a new blocking valve core. This increases the reliability of the sample fluid sealing inside the valve body 1 after the valve core 5 breaks, reducing the impact of seawater seepage into the sample fluid inside the valve body 1. At the same time as the shaft 51 breaks, the screw of the drive device 7 rotates and contacts the nut 71. The screw is threadedly engaged with the gland 2, and through the self-locking property of the thread, the valve core 5 breaks instantly. The increased pressure is transferred to the thread engagement between the screw and the gland 2, thereby inhibiting the axial movement of the screw. This ensures that the protrusion 52 of the valve core 5 is always in contact with the screw, and is always in contact with the left side of the valve sleeve 4. That is, at the moment the valve core 5 breaks, the broken shaft 51 forms a secondary sealing structure, which, combined with the self-locking of the output shaft thread of the drive device 7, inhibits the drive device 7 from moving in the opposite direction. The two work together to ensure that even after the valve core 5 breaks, it can still ensure that the sample in the cavity 6 and the sampling tube is not contaminated by external seawater.

[0039] On the other hand, after the plug valve is removed, the operator can observe the fit between the protrusion 55 and the inner bushing 13 through the port on the right side of the valve body 1, and thus understand whether the valve core 5 is damaged. This avoids the need for the operator to disassemble the valve to understand the usage status of the valve core 5, thus improving practicality.

[0040] In conclusion, 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 deep-sea sampling plug valve, comprising a valve body (1), characterized in that: One end of the valve body (1) is fitted with a detachable pressure cap (2). The valve body (1) and the pressure cap (2) form a hollow cylindrical structure with one end closed and the other end open. Port 1 (11) and port 2 (12) are respectively opened on the two opposite outer sides of the valve body (1). Valve sleeve 1 (3) and valve sleeve 2 (4) are embedded inside the valve body (1) and are distributed along the axis. A cavity (6) is formed between valve sleeve 1 (3) and valve sleeve 2 (4). Port 1 (11), cavity (6) and port 2 (12) form a sampling path. The valve body ( 1) has a valve core (5) inside, which is movably embedded in valve sleeve one (3) and valve sleeve two (4). The valve core (5) moves axially to make the sampling passage sealed or connected. A nut (71) is installed at one end of the valve core (5). A drive device (7) is provided on the side of the nut (71) away from the valve core (5). The output end of the nut (71) presses against the nut (71). An elastic element (21) is provided inside the pressure cover (2). The two ends of the elastic element (21) are connected to the nut (71) and the inner wall of the pressure cover (2) respectively. The valve core (5) includes a shaft (51), and a protrusion (52) is provided at the middle position of the shaft (51). The joint between the protrusion (52) and the shaft (51) is chamfered. The two sides of the protrusion (52) are respectively adapted to valve sleeve one (3) and valve sleeve two (4). The shaft (51) has a groove 1 (53) and a groove 2 (54) at its end position, and an O-ring is fitted in both the groove 1 (53) and the groove 2 (54). The valve body (1) has an inner bushing (13) fixedly embedded inside the opening end, and the end of the shaft (51) is stepped with the inner bushing (13). The shaft (51) has a protrusion (55) integrally formed at the end near the inner bushing (13), and the size of the protrusion (55) is adapted to the inner diameter of the inner bushing (13).

2. The deep-sea sampling plug valve according to claim 1, characterized in that: The driving device (7) is a linear screw driving device, and the driving device (7) and the pressure cap (2) are threaded together.

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