A structure of a swivel one-way valve

Abstract

The application relates to the technical field of isolation pipeline, and a structure of a one-way valve of a crane pipe comprises a oil distribution head, an outlet one-way valve body, an oil discharge one-way valve body and an oil pan; the outlet one-way valve body comprises an outlet upper valve body, a connecting surface and an outlet lower valve body; a second annular protrusion is arranged on the inner wall of the outlet upper valve body, and a second oil inlet is arranged at the center of the connecting surface; the outlet lower valve body is inwardly provided with a second folded edge; the outlet upper valve body is arranged outside the oil distribution head and is in sliding connection with the oil distribution head; the outlet one-way valve body is internally provided with the oil discharge one-way valve body; the oil discharge one-way valve body comprises a valve core top cap, an oil discharge upper valve body, an oil discharge lower valve body and the outlet lower valve body in sliding connection; the outlet one-way valve is responsible for the loading and unloading of main fluid oil distribution; the oil discharge one-way valve is responsible for discharging residual oil liquid of the vertical pipe; and the oil pan recovers residual oil liquid outside the vertical pipe. The design structure of the application guarantees that the internal oil liquid and oil gas cannot be discharged outward, and at the same time, the oil liquid on the outer pipe can be recovered, so that the oil liquid cannot drip on the tank body and the platform during the crane pipe recovery process.

Description

Technical Field

[0001] This application relates to the field of isolation pipeline technology, and in particular to a one-way valve structure for an arm-loader. Background Technology

[0002] In related technologies, gasoline loading systems mostly use loading arms, which are generally in the form of jacketed arms. After loading, although jacketed loading arms or steam purging are used, there is a drawback: residual medium on the vertical pipe wall cannot be extracted. As it flows out of the pipe wall, it inevitably carries away volatile oil and gas, causing a risk of flammable gas overflow and flash explosion. Most petrochemical companies require the oil in the vertical pipe to stand until it is almost dripping, according to the manufacturer's requirements, or the operating instructions require it to stand for more than five minutes before retracting the vertical pipe section. However, on-site workers generally ignore the waiting time during actual operation. Even after standing for five minutes, there is still a problem of residual oil in the sleeve separating from the pipe wall due to vibration during the retraction of the loading arm by the pneumatic actuator, resulting in residual oil dripping. At the same time, the strong odor on site affects loading efficiency and is not safe or environmentally friendly.

[0003] Current technologies innovate the loading arm structure by adding an automatic oil pan at the end of the loading arm's vertical pipe to prevent gasoline from dripping in the straight section of the loading arm. However, the problem of gasoline spillage has not been completely solved. Furthermore, the added oil pan structure increases the structural size of the loading arm, requiring modifications to the platform guardrail structure. At the same time, the electrical system increases the operational safety risks on site.

[0004] Therefore, it is evident that the related technologies have certain shortcomings in addressing gasoline dripping and oil / gas spillage issues. Summary of the Invention

[0005] To overcome the above-mentioned defects, this application provides a one-way valve structure for loading arms, which can solve the hidden dangers of flash explosion and air pollution caused by oil and oil gas leakage by sealing the loading arm outlet, while saving product loading and unloading time and the waste caused by oil dripping, thereby maximizing production efficiency.

[0006] This application provides a loading arm check valve structure, including an oil distributor, an outlet check valve body, a drain check valve body, and an oil pan; The oil distributor is connected to the lower end of the vertical pipe of the loading arm. The first oil inlet at the top of the oil distributor is connected to the vertical pipe, and the first oil outlet is provided at the bottom. The inner wall of the oil distributor is provided with a first annular protrusion, and the bottom is provided with a first folded edge outward. The outlet check valve body includes an upper outlet valve body, a connecting surface, and a lower outlet valve body; the upper outlet valve body has a second annular protrusion on its inner wall, and a second oil inlet is provided at the center of the connecting surface; the lower outlet valve body has a second folded edge extending inward. The outlet valve body is located outside the oil distributor and is slidably connected to the oil distributor. A first elastic element is provided between the outlet check valve body and the oil distributor. The top end of the first elastic element abuts against the second annular protrusion (23) of the outlet check valve body, and the bottom end of the first elastic element abuts against the first folded edge of the oil distributor. The outlet check valve body is internally equipped with a drain check valve body, which includes a valve core cap, an upper drain valve body, and a lower drain valve body. The outer wall of the valve core cap fits with the inner wall of the first annular protrusion. The upper drain valve body is provided with multiple fourth oil inlets, which are connected to the lower drain valve body. The bottom of the lower drain valve body is detachably connected to an oil pan, and the bottom of the lower drain valve body is provided with a second oil outlet. The lower drain valve body is slidably connected to the outlet lower valve body. A second elastic element is provided between the outlet check valve body and the drain check valve body. The top end of the second elastic element abuts against the lower surface of the upper drain valve body, and the bottom end of the second elastic element abuts against the second folded edge of the outlet check valve. The oil pan is equipped with a third oil outlet at the position of the second oil outlet of the outlet check valve body.

[0007] Furthermore, the first elastic element is configured as a first spring; the second elastic element is configured as a second spring.

[0008] Furthermore, the inner wall of the oil distributor is provided with a frustum-shaped flow distribution structure, and the frustum-shaped flow distribution structure is provided with multiple first oil inlet holes.

[0009] Furthermore, multiple second oil inlet holes are evenly arranged on the upper part of the oil distributor.

[0010] Furthermore, both the upper and lower valve bodies at the outlet are designed as hollow cylinders, with the connecting surface being an annular connecting surface; the outer periphery of the connecting surface connects to the bottom of the upper valve body at the outlet, and the inner wall of the connecting surface connects to the top of the lower valve body at the outlet.

[0011] Furthermore, multiple third oil inlet holes are evenly arranged on the valve body at the outlet; when the bottom surface of the first folded edge abuts against the connecting surface, the third oil inlet hole is higher than the second oil inlet hole.

[0012] Furthermore, the oil pan is designed as an upward-opening circular groove, with a diameter larger than that of the valve body at the outlet; multiple oil drain pipes are installed inside the oil pan.

[0013] Furthermore, the oil drain pipe includes a vertical section, a horizontal section, and an inclined section connected in sequence, with an opening in the inclined section and an outlet in the vertical section.

[0014] Furthermore, the outlet check valve body is provided with an annular groove facing the oil distributor, and a sealing ring is provided in the annular groove.

[0015] This application has the following beneficial effects: This application's outlet check valve is responsible for the main fluid distribution during loading and unloading, while the drain check valve is responsible for discharging residual oil from the vertical pipe, and the oil pan recovers residual oil from the outside of the vertical pipe. The design of this application seals the loading arm outlet, ensuring that internal oil and oil vapors do not leak out, while simultaneously recovering oil from the outer pipe, ensuring that oil does not drip onto the tank or platform during loading arm recovery. This application completely seals the loading arm outlet, ensuring that oil and gas inside the pipeline do not leak out, thus preventing safety and environmental problems, and preventing oil from dripping from the outer wall of the pipeline during loading arm recovery. Attached Figure Description

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a cross-sectional view of the overall structure of this application; Figure 3 This is a cross-sectional view of the oil distribution head structure of this application: Figure 4 This is a cross-sectional view of the valve body structure of the export check valve in this application; Figure 5 This is a cross-sectional view of the valve body structure of the oil discharge check valve in this application; Figure 6 This is a cross-sectional view of the oil pan structure in this application; Figure 7 This is a schematic diagram of the first state structure of this application; Figure 8 This is a schematic diagram of the second state structure of this application; Figure 9 This is a schematic diagram of the third state structure of this application; Figure 10 This is a schematic diagram of the fourth state structure of this application.

[0017] Reference numerals in the attached diagram: 1. Oil distributor head; 2. Outlet check valve body; 3. Drain check valve body; 4. First spring; 5. Sealing ring; 6. Drain pipe; 7. Oil pan; 8. Second spring; 9. Vertical pipe; 11. First oil inlet; 12. First oil outlet; 13. First annular protrusion; 14. First guide surface; 15. First folded edge; 16. Diverting structure; 17. First oil inlet hole; 18. Second oil inlet hole; 21. Second oil inlet; 23. Second annular protrusion; 25. Second folded edge; 28. Third oil inlet hole; 30. Valve core cap; 32. Second oil outlet; 34. Second guide surface; 38. Fourth oil inlet hole; 69. Inlet; 70. Outlet; 72. Third oil outlet. Detailed Implementation

[0018] The specific embodiments of this application are described below with reference to the accompanying drawings and examples. Through the content described in this specification, those skilled in the art can clearly and completely understand the technical solution, the technical problem solved, and the resulting technical effects of this application. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, for ease of description, only the parts related to this application are shown in the accompanying drawings.

[0019] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the contents described in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size should fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0020] The use of terms such as "first," "second," and "the" does not imply quantity limitation and may indicate singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or units, but may also include steps or units not listed, or other steps or units inherent to such processes, methods, products, or devices. The terms "connected," "linked," and "coupled" used in this application are not limited to physical or mechanical connections, but may also include direct or indirect electrical connections.

[0021] It should also be noted that the longitudinal section corresponding to the embodiment of this application can be the section corresponding to the front view direction, the transverse section can be the section corresponding to the right view direction, and the horizontal section can be the section corresponding to the top view direction.

[0022] Furthermore, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] refer to Figure 1 — Figure 6 The oil distributor 1 is connected to the lower end of the vertical pipe 9 of the loading arm. (Refer to...) Figure 3The oil distributor 1 has a first oil inlet 11 at the top connected to the vertical pipe 9, and a first oil outlet 12 at the bottom. The inner wall of the oil distributor 1 has a first annular protrusion 13; the first annular protrusion 13 has a frustum-shaped first guide surface 14, narrower at the top and wider at the bottom. The oil distributor 1 is a hollow cylinder with a larger diameter at the top than at the bottom. A first flange 15 is provided at the bottom of the lower part, with the outer diameter of the first flange 15 being the same as the outer diameter of the upper part. The overall outer diameter of the oil distributor 1 is slightly smaller than the inner wall diameter of the outlet check valve body 2. The outer wall of the oil distributor 1 and the inner wall of the outlet check valve body 2 can slide relative to each other. The upper part of the oil distributor and the first folded edge 15 leave room for the first spring 4 to move. The inner wall of the oil distributor 1 is provided with a frustum-shaped diversion structure 16, and multiple first oil inlet holes 17 are provided on the frustum-shaped diversion structure 16. Multiple second oil inlet holes 18 are evenly provided on the upper part of the oil distributor 1, and the second oil inlet holes 18 are set as square holes. The outlet check valve body 2 is provided with an annular groove facing the oil distributor 1, and a sealing ring 5 is provided in the annular groove.

[0024] Reference Figure 4 The outlet check valve body 2 is located around the oil distributor head 1. The outlet check valve body 2 includes an integrally formed upper outlet valve body, a connecting surface, and a lower outlet valve body. Both the upper outlet valve body and the lower outlet valve body are hollow cylinders. A circular second oil inlet 21 is provided at the center of the annular connecting surface. The connecting surface is horizontal. The outer periphery of the annular connecting surface is connected to the bottom of the upper outlet valve body. The inner wall of the connecting surface forms the second oil inlet 21, which is connected to the top of the lower outlet valve body. The upper valve body at the outlet has a second annular protrusion 23 on its inner wall. The diameter of the inner wall of the upper valve body at the outlet is slightly larger than the diameter of the outer wall of the oil distributor 1. The inner wall of the upper valve body at the outlet is in contact with the outer wall of the oil distributor 1. When the bottom of the first folded edge 15 of the oil distributor 1 abuts against the top of the connecting surface, the upper surface of the second annular protrusion 23 abuts against the lower surface of the upper part of the oil distributor 1. The first spring 4 is in its natural state, located between the lower part of the oil distributor 1 and the upper valve body at the outlet. Specifically, the bottom of the lower valve body at the outlet has a second folded edge 25 arranged inward. The second folded edge 25 is an annular folded edge. The top of the first spring 4 abuts against the lower surface of the second annular protrusion 23 of the valve body 2 of the one-way valve at the outlet, and the bottom of the first spring 4 abuts against the first folded edge 15 of the oil distributor 1. The upper valve body at the outlet has multiple third oil inlet holes 28 evenly arranged. When the bottom surface of the first folded edge 15 abuts against the connecting surface, the third oil inlet hole 28 is higher than the second oil inlet hole 18. The third oil inlet hole 28 and the second oil inlet hole 18 correspond one-to-one but are not connected.

[0025] Reference Figure 5 and Figure 7The drain valve body 3 includes an integrally formed valve core cap 30, an upper drain valve body, and a lower drain valve body. The valve core cap 30 is shaped like a frustum, and the side wall of the frustum is the second guide surface 34. The second guide surface 34 has the same inclination angle and height as the first guide surface 14, and they fit together perfectly. The upper drain valve body is provided with multiple fourth oil inlet holes 38, which connect to the lower drain valve body. The lower drain valve body is a hollow cylinder for draining oil, and its diameter is smaller than that of the lower drain valve body. The diameter of the lower drain valve body is matched with the inner diameter of the second fold 25 of the lower outlet valve body; the height of the lower drain valve body is the same as the height of the lower outlet valve body, and the second spring 8 is located between the lower drain valve body and the lower outlet valve body; when the bottom surfaces of both the lower drain valve body and the lower outlet valve body are in contact with the bottom of the oil receiving tray 7, and the bottom of the first fold 15 of the oil distributor 1 and the top of the connecting surface are in contact, the first guide surface 14 and the second guide surface 34 are in contact, the outlet check valve body 2 is closed, and the second spring 8 is in its natural state. The top of the second spring 8 is in contact with the lower surface of the upper drain valve body, and the bottom of the second spring 8 is in contact with the second fold 25 of the outlet check valve.

[0026] Reference Figure 6 The oil pan 7 is designed as an upward-opening circular groove, the diameter of which is larger than the diameter of the outlet valve body. Multiple oil drain pipes 6 are installed inside the oil pan 7. The bottom of the lower oil drain valve body is detachably connected to the oil pan 7, and a second oil outlet 32 ​​is provided at the bottom of the lower oil drain valve body. A third oil outlet 72 is provided on the oil pan 7 corresponding to the second oil outlet 32 ​​of the outlet check valve body 2. The oil drain pipe 6 includes a vertical section, a horizontal section, and an inclined section connected in sequence. The inclined section has an inlet 69, and the vertical section has an outlet 70.

[0027] The oil distributor 1, the outlet check valve body 2, and the first spring 4 work together to form an outlet check valve. The oil distributor 1, the outlet check valve body 2, the drain check valve body 3, and the second spring 8 work together to form a drain check valve. The oil pan 7 and the drain pipe 6 are connected to the drain check valve body 3 to form an oil receiving pan. The outlet check valve is connected to the vertical pipe 9 of the loading arm mechanism through the oil distributor 1 to form an integral structure.

[0028] The outlet check valve is controlled by the outlet pressure of the first spring 4 and the vertical pipe 9. The opening degree is limited by the valve body 2 and the stop of the oil distributor 1 to ensure that the outlet check valve is in the fully open or fully closed position.

[0029] The oil discharge check valve is controlled by the gravity of the residual oil in the second spring 8 and the vertical pipe 9 to open and close. The opening degree is limited by the upper and lower surfaces of the oil discharge check valve body 3, the upper valve body and the valve core cap 30, the oil distributor head 1 and the outlet check valve body 2.

[0030] The oil receiving pan is connected to the oil drain check valve body 3 via the oil pan 7 and the oil drain pipe 6. The oil drain pipe 6 drains the oil dripping from the outer wall of the vertical pipe 9 into the tank through the siphon effect of gravity and air pressure. When the liquid level reaches the inlet 69 of the oil drain pipe 6, the oil draining stops, and the oil pan only allows oil to flow in but not out.

[0031] Specifically, refer to Figures 7-10 The outlet check valve, through the reaction force of the first spring 4, keeps the outlet of the oil distributor 1 in the closed state, i.e., the initial first state. Figure 7 As shown, the bottom of the first fold 15 of the oil distributor 1 abuts against the top of the connecting surface, and the bottom outer wall of the lower oil discharge valve body and the inner wall of the second fold 25 are in contact. The outlet check valve is closed.

[0032] When the oil is pumped from the upstream pump to the oil distributor 1 at the end of the vertical pipe 9, the oil pressure pushes the valve core cap 30, closing the drain check valve to the bottom. Figure 8 As shown, in the second state, the diameter of the valve core cap 30 is larger than that of the second oil inlet 21, and the valve core cap 30 is in contact with the connecting surface. The drain check valve is closed.

[0033] The oil pressure then opens the outlet check valve through the top connecting surface, sending the oil into the tank. Figure 9 In the third state, the oil flows through the diversion structure 16, the first guide surface 14 of the first annular protrusion 13, and into the fourth oil inlet 38, then flows out from the second oil outlet 32 ​​and the third oil outlet 72. Both the outlet check valve and the drain check valve are open. Furthermore, at this time, the third oil inlet 28 and the second oil inlet 18 are connected in a one-to-one correspondence.

[0034] After the transfer is completed, the oil pressure drops below the critical value of the first spring 4's reaction force, the outlet check valve closes, and the drain check valve gradually closes after draining the remaining oil from the vertical pipe 9 into the tank. Simultaneously, the oil in the oil pan 7 and the oil flowing into the oil pan 7 from the outside of the pipe wall are drained into the tank through the drain pipe 6 of the oil pan 7 via a siphon effect. Figure 10 When the oil level drops to the inlet 69 of the drain pipe 6 at the bottom of the oil pan 7, air enters and the oil pan 7 stops draining oil; oil enters the oil pan 7 but does not drain, and the oil stops dripping. The loading arm retracts via a pneumatic mechanism. Throughout the process, the loading arm remains closed, and almost no oil drips from the outer wall of the pipe. After the loading arm retracts above the recovery oil pan 7, the operator manually pulls the lower drain check valve to completely drain the remaining oil from the pipe. The entire process is completed in less than 5 minutes, far less than the 15 minutes required by existing related technologies.

[0035] The working principle of this application embodiment is as follows: When oil delivery begins, the pumped oil raises the pipeline pressure above the reaction force of the first spring 4. The outlet check valve body 2 descends to the stop limit and contacts the first folded edge of the distributor head 1, fully opening the outlet check valve and achieving the fastest delivery speed. As the pipeline oil pressure rises, the oil first fills the outlet check valve, and the valve core cap 30 descends to the outlet check valve connection surface, blocking the drain check valve. The outlet check valve then opens under pipeline pressure.

[0036] When the outlet check valve is closed, the residual oil pressure is less than the reaction force of the second spring 8, and the drain check valve gradually opens. When the oil weight is less than the reaction force of the second spring 8, the drain check valve is completely closed, and the draining is completed.

[0037] When the loading arm is raised above the oil level in the tank, the remaining oil in the submerged section 9 of the loading arm flows down the pipe wall into the oil pan 7. When the oil pan 7 is full, the oil level is higher than the drain pipe 6, and the drain hole begins to drain oil. When the oil level in the oil pan 7 drops to the inlet position of the drain pipe 6, air enters the drain pipe 6, and the draining stops. The oil flowing down from above enters the oil pan 7 and is not discharged. The loading arm retracts via a pneumatic structure, solving the problem of oil dripping. When it returns to the top of the recovery oil pan 7, the operator can pull down the oil pan 7 as needed to discharge the remaining oil from the submerged section 9.

[0038] Although this application has been described and illustrated with reference to specific embodiments thereof, such description and illustration are not limiting of this application. It will be readily understood by those skilled in the art that various changes can be made and equivalent elements can be substituted within embodiments without departing from the true spirit and scope of this application as defined by the appended claims. Illustrations may not be drawn to scale. Differences may exist between the technical representation in this application and actual implementation due to variables in the manufacturing process, etc. Other embodiments of this application may exist that are not specifically described. The description and illustrations should be considered illustrative rather than restrictive. Modifications can be made to adapt particular circumstances, materials, composition, methods, or processes to the objectives, spirit, and scope of this application. All such modifications fall within the scope of the appended claims. While the methods disclosed herein have been described with reference to specific operations performed in a particular order, it should be understood that these operations can be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of this application. Therefore, unless specifically indicated herein, the order and grouping of operations do not limit this application.

Claims

1. A one-way valve structure for an arm-mounted loading arm, characterized in that, It includes an oil distribution head (1), an outlet check valve body (2), an oil discharge check valve body (3), and an oil pan (7); The oil distributor (1) is connected to the lower end of the vertical pipe (9) of the loading arm. The first oil inlet (11) at the top of the oil distributor (1) is connected to the vertical pipe (9), and the first oil outlet (12) is provided at the bottom. The inner wall of the oil distributor (1) is provided with a first annular protrusion (13), and the bottom is provided with a first folded edge (15) facing outward. The outlet check valve body (2) includes an outlet upper valve body, a connecting surface and an outlet lower valve body; the inner wall of the outlet upper valve body is provided with a second annular protrusion (23), and the center of the connecting surface is provided with a second oil inlet (21); the outlet lower valve body is provided with a second folded edge (25) inward; The outlet valve body is located outside the oil distributor (1) and is slidably connected to the oil distributor (1). A first elastic element is provided between the outlet check valve body (2) and the oil distributor (1). The top end of the first elastic element abuts against the second annular protrusion (23) of the outlet check valve body (2), and the bottom end of the first elastic element abuts against the first folded edge (15) of the oil distributor (1). The outlet check valve body (2) is internally provided with an oil drain check valve body (3). The oil drain check valve body (3) includes a valve core cap (30), an upper oil drain valve body, and a lower oil drain valve body. The outer wall of the valve core cap (30) fits with the inner wall of the first annular protrusion (13). The upper oil drain valve body is provided with multiple fourth oil inlet holes (38), which are connected to the lower oil drain valve body. The bottom of the lower oil drain valve body is detachably connected to an oil pan (7). The bottom of the lower oil drain valve body is provided with a second oil outlet (32). The lower oil drain valve body is slidably connected to the lower outlet valve body. A second elastic element is provided between the outlet check valve body (2) and the oil drain check valve body (3). The top of the second elastic element abuts against the lower surface of the upper oil drain valve body, and the bottom of the second elastic element abuts against the second folded edge (25) of the outlet check valve. The oil pan (7) is provided with a third oil outlet (72) at the position of the second oil outlet (32) of the outlet check valve body (2).

2. The one-way valve structure for the loading arm according to claim 1, characterized in that, The first elastic element is configured as a first spring (4); the second elastic element is configured as a second spring (8).

3. The one-way valve structure for the loading arm according to claim 1, characterized in that, The inner wall of the oil distributor (1) is provided with a frustum-shaped flow distribution structure (16), and the frustum-shaped flow distribution structure (16) is provided with multiple first oil inlet holes (17).

4. The one-way valve structure for the loading arm according to claim 1, characterized in that, The upper part of the oil distributor (1) is evenly provided with multiple second oil inlet holes (18).

5. The one-way valve structure for the loading arm according to claim 1, characterized in that, Both the upper and lower valve bodies at the outlet are hollow cylinders with annular connecting surfaces. The outer periphery of the connecting surface connects to the bottom of the upper valve body at the outlet, while the inner wall of the connecting surface connects to the top of the lower valve body at the outlet.

6. The one-way valve structure for the loading arm according to claim 4, characterized in that, Multiple third oil inlet holes (28) are evenly arranged on the valve body at the outlet; when the bottom surface of the first folded edge (15) abuts against the connecting surface, the third oil inlet hole (28) is higher than the second oil inlet hole (18).

7. The one-way valve structure for the loading arm according to claim 1, characterized in that, The oil pan (7) is set as an upward-opening circular groove with a diameter larger than the diameter of the valve body at the outlet; multiple oil drain pipes (6) are provided inside the oil pan (7).

8. The one-way valve structure for the loading arm according to claim 7, characterized in that, The oil drain pipe (6) includes a vertical section, a horizontal section and an inclined section connected in sequence. The inclined section is provided with an inlet (69) and the vertical section is provided with an outlet (70).

9. The one-way valve structure for the loading arm according to claim 1, characterized in that, The outlet check valve body (2) is provided with an annular groove facing the oil distributor (1), and a sealing ring (5) is provided in the annular groove.

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