Tank car sampling system

Abstract

The utility model belongs to the technical field of tank car sampling, and provides a tank car sampling system which comprises a gas phase quick connector, a liquid phase quick connector; the sampling pipeline is provided with a sampling discharge valve and a sampling branch; the purging pipeline is provided with a purging gas cylinder, a purging branch, a material returning branch and a feeding pipeline for communicating the purging branch with the material returning branch; wherein the tail end of the sampling pipeline is connected with the purging branch, the tail end of the purging branch is connected with the gas-phase quick connector, and the tail end of the material returning branch is connected with the liquid-phase quick connector. The tank car sampling system provided by the utility model can be used for under-pressure and normal-pressure sampling of a tank car, whether the tank car gas phase port is connected or not is selected as required, different tank car sampling requirements are met, the limitation of a sampling bottle on sampling operation is solved, the practicability is high, and the application range is wide; circulating sample liquid and rinsing sample liquid in the sampling process can be recycled into the tank car, sampling personnel are prevented from climbing to the top of the tank car to operate, and the safety of operators in the sampling process is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of tanker sampling, and particularly relates to a tanker sampling system. Background Art

[0002] At present, the current tanker sampling method is generally manual sampling at a fixed position. It is necessary to park the tanker at the designated sampling and testing position, and at the same time, it is necessary for the operator to climb onto the tanker to perform corresponding operations. There are the following problems and defects in using the above method for tanker sampling:

[0003] (1) It is difficult to recycle the circulating sample liquid generated during the tanker sampling process and the sample material generated by rinsing the sample bottle. Often, it is necessary for the sampling personnel to climb to the top of the tanker to open the lid for recycling. The whole process is highly dangerous and prone to safety accidents;

[0004] (2) After the existing sampling device completes sampling, there is residual sample liquid inside the sampler pipeline. When sampling different vehicle trips and different materials, it needs to be manually cleaned or replaced, and continuous sampling for multiple vehicle trips is not possible, resulting in low sampling efficiency;

[0005] (3) It is necessary to park the tanker at the designated sampling and testing position, and sampling can only be carried out at a fixed position, with low flexibility and poor convenience of the sampling operation;

[0006] (4) The gas-phase connection ports of some tankers are set at the top of the tanker and are not led to the bottom of the tanker or a position convenient for connection operations. During the process of connecting the gas-phase ports, it is necessary for the sampling personnel to get on and off the vehicle to operate, with cumbersome steps and safety risks;

[0007] (5) The existing samplers are only compatible with a single type of sampling bottle, such as a sampler only compatible with an open bottle or a sampler only compatible with a closed sampling bottle. There are restrictions on the type of sampling bottle used. Different samplers need to be selected for different sampling operations, with poor practicability;

[0008] Therefore, it is necessary to design a tanker sampling system that can effectively solve the above problems and defects. Summary of the Invention

[0009] In order to solve the above technical problems, the utility model provides a tanker sampling system, which can be used for pressurized and atmospheric sampling of tankers. It can be selected whether to connect the gas-phase port of the tanker according to needs, improving the flexibility and convenience of use, meeting different tanker sampling requirements. At the same time, it can be used for sampling different sampling bottles, solving the limitation of sampling bottles on sampling operations, with strong practicability and wide application range. It can recycle the circulating sample liquid and rinsing sample liquid during the sampling process back into the tanker, avoiding the need for sampling personnel to climb to the top of the tanker to operate, ensuring the safety of the operating personnel during the sampling process, and ensuring that there is no residual sample liquid in the pipeline, avoiding cross-contamination between sample materials caused by residual sample liquid, and ensuring the accuracy and representativeness of sampling.

[0010] The technical solution of the utility model is:

[0011] The utility model provides a tank truck sampling system, comprising:

[0012] A gas phase quick interface, which is detachably connected to the gas phase interface of the tank truck;

[0013] A liquid phase quick interface, which is detachably connected to the liquid phase interface of the tank truck;

[0014] A sampling pipeline, wherein the sampling pipeline is provided with a sampling discharge valve and a sampling branch, the sampling discharge valve is arranged close to the liquid phase quick interface, and the sampling branch is provided with a sampling bottle connected thereto;

[0015] A purge pipeline, wherein the purge pipeline is provided with a purge gas bottle, a purge branch and a material return branch connected to the purge gas bottle, and a material feeding pipeline connecting the purge branch and the material return branch;

[0016] Among them, the end of the sampling pipeline is connected to the purge branch, the end of the purge branch is connected to the gas phase quick interface, and the end of the material return branch is connected to the liquid phase quick interface.

[0017] Preferably, the purge branch is provided with a gas phase shut-off valve, a jet pump, and a connecting valve which are connected in sequence, the gas phase shut-off valve is arranged close to the gas phase quick interface, and the jet pump is connected to the end of the sampling pipeline.

[0018] Preferably, the material return branch is provided with a gas phase balance valve and a pipeline pressure gauge arranged close to the purge gas cylinder, the purge gas cylinder is provided with a gas cylinder valve, and the feeding pipeline is provided with a feeding valve.

[0019] Preferably, the sampling branch includes an open branch and a closed branch, the open branch is connected in parallel to the sampling pipeline, and the closed branch is connected in series to the sampling pipeline;

[0020] The open branch is located between the sampling and discharging valve and the closed branch.

[0021] Preferably, the open branch is provided with an on-site sampling port and a liquid material collecting tank which are connected to the sampling pipeline, and the on-site sampling port is located above the liquid material collecting tank;

[0022] The on-site sampling port is provided with a sampling valve, and the liquid material collecting tank is provided with a collecting tank valve.

[0023] Preferably, the open branch is further provided with a material collecting branch connected to the purge branch, and the end of the material collecting branch is arranged above the liquid material collecting tank;

[0024] The material collecting branch is provided with a material collecting valve.

[0025] Preferably, the closed branch is provided with a closed sampling bottle connected in series to the sampling pipeline, and a bypass branch connected in parallel to the closed sampling bottle;

[0026] The feeding end of the sealed sampling bottle is provided with a feeding valve, the discharging end is provided with a discharge valve, and the bypass branch is provided with a bypass valve.

[0027] Preferably, the closed branch is further provided with a flushing circulation pump connected in series to the sampling pipeline, the flushing circulation pump is provided with an air source pipeline connected to the purge pipeline, and the air source pipeline is provided with an air source valve.

[0028] Preferably, the sampling pipeline is also provided with a sampling liquid level meter, and the sampling liquid level meter is located between the sampling discharge valve and the sampling branch.

[0029] Preferably, the tank truck sampling system provided by the utility model further comprises a grounding branch, wherein the grounding branch is provided with an electrostatic clip, an electrostatic alarm, an on-site grounding terminal, and a human body electrostatic release button which are connected in sequence;

[0030] The electrostatic clip is detachably connected to the grounding terminal of the tank truck.

[0031] Compared with the prior art, the utility model has the following advantages and effects:

[0032] (1) A purge pipeline with a purge branch and a return branch is used. After sampling is completed, the residual sample liquid inside the pipeline can be collected and cleaned through the purge branch to ensure that there is no liquid inside the pipeline, thereby facilitating continuous and uninterrupted sampling by the sampling system, avoiding contamination between different samples during the sampling process, ensuring sampling accuracy and improving sampling efficiency. The return branch can recover part of the circulating sample material into the tank truck, without the need for manual climbing to the top of the tank truck to open the cover for recovery, thereby improving the convenience of sampling and ensuring the personal safety of the sampling personnel;

[0033] (2) The sampling pipeline includes an open branch and a closed branch. The open branch can be adapted to the sampling of an open sampling bottle, and the closed branch can be adapted to the sampling of a closed sampling bottle. This allows the overall sampling system to be adapted to the sampling of different sampling bottles at the same time, eliminating the restrictions of the sampling bottles on the sampling system, improving practicality and expanding the scope of application, and meeting different sampling needs at the same time;

[0034] (3) A purge line equipped with a purge gas bottle can be used. Whether to connect to the gas phase port of the tank truck can be selected according to the sampling needs and convenience. It can meet the pressure sampling and normal pressure sampling needs of the tank truck at the same time. For example, when the gas phase port of the tank truck is set on the top of the tank truck or in a position that is difficult to connect, it can be selected to connect only to the liquid phase port of the tank truck for sampling, without the time-consuming and laborious connection of the gas phase port of the tank truck, thereby improving the convenience and flexibility of the sampling operation. Description of the Drawings

[0035] Figure 1 This is a schematic structural diagram of the sampling system of the tanker in the embodiment of the present utility model.

[0036] Reference numerals: 1, gas-phase quick connector; 2, liquid-phase quick connector; 3, sampling pipeline; 31, sampling discharge valve; 32, sampling liquid level gauge; 4, sampling branch; 41, open branch; 411, on-site sampling port; 412, liquid material collection tank; 413, sampling valve; 414, collection tank valve; 415, aggregate branch; 416, aggregate valve; 42, closed branch; 421, airtight sampling bottle; 422, bypass branch; 423, feed valve; 424, discharge valve; 425, bypass valve; 426, rinsing circulation pump; 427, gas source pipeline; 428, gas source valve; 5, purge pipeline; 51, purge gas cylinder; 511, gas cylinder valve; 52, purge branch; 521, gas-phase cut-off valve; 522, jet pump; 523, connection valve; 53, material return branch; 531, gas-phase balance valve; 532, pipeline pressure gauge; 54, feeding pipeline; 541, feeding valve; 6, grounding branch; 61, static clamp; 62, static alarm; 63, on-site grounding terminal; 64, human body static electricity release button. Detailed Embodiment

[0037] In order to enable those skilled in the art to better understand the present utility model, the present utility model will be further described below in conjunction with the specific embodiments.

[0038] Embodiment:

[0039] As Figure 1 shown, the present utility model provides a sampling system for a tanker, including a gas-phase quick connector 1 for connecting the gas-phase port of the tanker, a liquid-phase quick connector 2 for connecting the liquid-phase port of the tanker, a sampling pipeline 3 for sampling, a purge pipeline 5 for purging and cleaning the liquid stored in the pipeline and recovering and collecting the sample material, and a grounding branch 6 for releasing static electricity. Among them, the gas-phase quick connector 1 is detachably and hermetically connected to the gas-phase interface of the tanker, and the liquid-phase quick connector 2 is detachably and hermetically connected to the liquid-phase interface of the tanker. During the sampling process, only the position of the sampling system needs to be moved and the gas-phase quick connector 1 and the liquid-phase quick connector 2 are connected to the gas-phase interface and the liquid-phase interface of the tanker. There are no requirements and restrictions on the position of the tanker. Compared with the existing sampling process where sampling can only be carried out at a fixed position, it has higher flexibility and convenience.

[0040] Refer to Figure 1As shown in the figure, the sampling pipeline 3 is provided with a sampling discharge valve 31, a sampling liquid level gauge 32, and a sampling branch 4 connected in sequence. The sampling discharge valve 31 is arranged close to the liquid-phase quick interface 2. The sampling liquid level gauge 32 is specifically a glass liquid level gauge, and the sampling personnel can observe the liquid level change inside the sampling liquid level gauge 32. The glass sampling liquid level gauge 32 is located between the sampling discharge valve 31 and the sampling branch 4. The end of the sampling branch 4 is connected to the purge pipeline 5. The sampling branch 4 is provided with a sampling bottle connected thereto. The sampling branch 4 includes an open branch 41 and a closed branch 42. The open branch 41 is connected in parallel to the sampling pipeline 3, and the closed branch 42 is connected in series to the sampling pipeline 3 and is connected to the purge pipeline 5. The open branch 41 is located between the sampling discharge valve 31 and the closed branch 42. Specifically, the open branch 41 is provided with a field sampling port 411 connected to the sampling pipeline 3 and a liquid material collection tank 412 connected to the sampling pipeline 3. The field sampling port 411 is provided with a sampling valve 413, and the liquid material collection tank 412 is provided with a collection tank valve 414. The field sampling port 411 is located above the liquid material collection tank 412. During the sampling process, an open sampling bottle is placed in the liquid material collection tank 412, and the liquid material is collected into the open sampling bottle through the field sampling port 411. At the same time, the liquid material for rinsing the open bottle sampling can be poured into the liquid material collection tank 412. The open branch 41 is also provided with an aggregate branch 415 connected to the purge branch 52 of the purge pipeline 5. The aggregate branch 415 is provided with an aggregate valve 416. One end of the aggregate branch 415 is arranged above the liquid material collection tank 412, and the other end is connected to the purge branch 52 of the purge pipeline 5 to collect the liquid material in the pipeline during the purge process into the liquid material collection tank 412.

[0041] Optionally, in some embodiments, one end of the aggregate branch 415 is connected to the liquid material collection tank 412 and is in communication with the liquid material collection tank 412, so as to directly transport the liquid material in the purged pipeline to the liquid material collection tank 412.

[0042] As Figure 1 shown in the figure, the closed branch 42 is provided with a closed sampling bottle 421 connected in series to the sampling pipeline 3 and a bypass branch 422 connected in parallel to the closed sampling bottle 421. The feed end of the closed sampling bottle 421 is provided with a feed valve 423, the discharge end of the closed sampling bottle 421 is provided with a discharge valve 424, and the bypass branch 422 is provided with a bypass valve 425. The closed branch 42 is also provided with a rinsing circulation pump 426 connected in series to the sampling pipeline 3. The rinsing circulation pump 426 is connected in series with the closed sampling bottle 421 and the bypass branch 422. The rinsing circulation pump 426 is a pneumatic centrifugal pump. The rinsing circulation pump 426 is provided with a gas source pipeline 427 connected to the purge pipeline 5. The gas source pipeline 427 is provided with a gas source valve 428.

[0043] Optionally, in some embodiments, the rinsing circulation pump 426 is an electric centrifugal pump and is equipped with a mobile power module connected thereto.

[0044] The purging pipeline 5 is provided with a purging gas cylinder 51, a purging branch 52 and a material discharging branch 53 connected to the purging gas cylinder 51, and a feeding pipeline 54 connecting the purging branch 52 and the material discharging branch 53. The purging gas cylinder 51 is provided with a gas cylinder valve 511. The purging branch 52 is connected to the end of the sampling pipeline 3, and the end of the purging branch 52 is connected to the gas-phase quick connector 1. The end of the material discharging branch 53 is connected to the liquid-phase quick connector 2. The two ends of the feeding pipeline 54 are respectively connected to the purging branch 52 and the material discharging branch 53, and the feeding pipeline 54 is provided with a feeding valve 541. The purging branch 52 is provided with a gas-phase cut-off valve 521, an ejector pump 522, and a connecting valve 523 connected in sequence. The gas-phase cut-off valve 521 is arranged close to the gas-phase quick connector 1. The ejector pump 522 is connected to the end of the sampling pipeline 3. The connection end of the feeding pipeline 54 and the purging branch 52 is located between the gas-phase cut-off valve 521 and the ejector pump 522. The material discharging branch 53 is provided with a gas-phase balance valve 531 and a pipeline pressure gauge 532 arranged close to the purging gas cylinder 51. The connection end of the feeding pipeline 54 and the material discharging branch 53 is arranged close to the liquid-phase quick connector 2.

[0045] The grounding branch 6 is provided with an electrostatic clamp 61, an electrostatic alarm 62, a field grounding end 63, and a human body static electricity release button 64 connected in sequence. The electrostatic clamp 61 is detachably connected to the grounding end of the tank truck. During the sampling process, the electrostatic clamp 61 is connected to the grounding end of the tank truck. The field grounding end 63 is grounded on the site. The sampling personnel touch the human body static electricity release button 64 to release the static electricity carried by the tank truck and themselves. The electrostatic alarm 62 includes an audible alarm (such as a buzzer) and / or a visual alarm (warning light) to remind the sampling personnel to perform the static electricity release operation.

[0046] The following describes the actual operation steps for sampling using the tank truck sampling system provided in this embodiment:

[0047] Sampling operation steps using an open sampling bottle and connecting to the gas phase port of the tank truck:

[0048] The operator touches the human body static electricity release button 64 with his hand, the sound alarm of the static electricity alarm 62 stops, and the light alarm changes from yellow to green; then close all valves on the sampling system; connect the static electricity clip 61 to the tank truck grounding terminal to release the static electricity of the tank truck until the static electricity alarm 62 stops alarming; connect the liquid phase quick interface 2 to the tank truck liquid phase interface, and the gas phase quick interface 1 to the tank truck gas phase interface in turn; open the sampling discharge valve 31; after observing that there is liquid in the glass sampling level gauge 32, place the open sampling bottle in the liquid material collection tank 412, open the sampling valve 413, and the material reaches the open sampling bottle through the on-site sampling port 411; the sampling personnel rinse the open sampling bottle, and the rinsed material can be poured into the liquid material collection tank 412; after obtaining a suitable sample, close the sampling valve 413. Close the liquid phase quick connector 2 in sequence, and open the bypass valve 425, the gas phase shut-off valve 521, the gas cylinder valve 511, the gas phase balance valve 531, the connecting valve 523, and the collecting tank valve 414; after observing that there is no liquid in the glass sampling level gauge 32, close all valves on the sampling system; disconnect the liquid phase quick connector 2, the gas phase quick connector 1, and the electrostatic clip 61 from the tank truck in sequence, and the sampling is completed.

[0049] Sampling operation steps using a sealed sampling bottle connected to the gas phase port of a tank truck:

[0050] The operator touches the human body static electricity release button 64 with his hand, the sound alarm of the static electricity alarm 62 stops, and the light alarm changes from yellow to green; then close all valves on the sampling system; connect the static electricity clip 61 to the tank truck grounding terminal to release the static electricity of the tank truck until the static electricity alarm 62 stops alarming; connect the liquid phase quick interface 2 to the tank truck liquid phase interface, and the gas phase quick interface 1 to the tank truck gas phase interface in turn; open the sampling discharge valve 31; after observing that there is liquid in the glass sampling level gauge 32, install the closed sampling bottle 421 on the sampling system; open the feed valve 423, the discharge valve 424, and the gas phase shut-off valve 521, and the material reaches the closed sampling bottle 421; open the gas cylinder valve 511 and the gas source valve 428, start the rinse circulation pump 426, and rinse the closed sampling bottle 421 (about 1 minute); after taking a suitable sample, close the feed valve 423, the discharge valve 424, the gas source valve 428, and remove the closed sampling bottle 421. Close the liquid phase quick connector 2 in sequence, and open the bypass valve 425, the gas phase balance valve 531, and the connecting valve 523; after observing that there is no liquid in the glass sampling level gauge 32, close all valves on the sampling system; disconnect the liquid phase quick connector 2, the gas phase quick connector 1, the electrostatic clip 61 from the tank truck in sequence, and the sampling is completed.

[0051] Sampling steps using an open sampling bottle without connecting to the gas phase port of the tank truck:

[0052] The operator touches the human body static electricity release button 64 with his hand, the sound alarm of the static electricity alarm 62 stops, and the light alarm changes from yellow to green; then close all valves on the sampling system; connect the static electricity clip 61 to the tank truck grounding terminal to release the static electricity of the tank truck until the static electricity alarm 62 stops alarming; connect the liquid phase quick interface 2 to the liquid phase interface of the tank truck; open the sampling discharge valve 31; after observing that there is liquid in the glass sampling level gauge 32, place the open sampling bottle in the liquid material collection tank 412, open the sampling valve 413, and the material reaches the open sampling bottle through the on-site sampling port 411; the material rinsed in the open sampling bottle can be poured into the liquid material collection tank 412; after obtaining a suitable sample, close the sampling and dispensing. Close the liquid phase quick interface 2 in sequence, and open the bypass valve 425, the collecting valve 416, the gas cylinder valve 511, the gas phase balance valve 531, and the connecting valve 523, and blow all the materials in the sampling system pipeline into the liquid material collecting tank 412; after observing that there is no liquid in the glass sampling liquid level gauge 32, close the collecting valve 416 and the sampling discharge valve 31; open the collecting tank valve 414, the feeding valve 541, and the liquid phase quick interface 2; after observing that there is no liquid in the glass sampling liquid level gauge 32, close the collecting tank valve 414, the liquid phase quick interface 2 and all valves on the sampling system; disconnect the liquid phase quick interface 2, the electrostatic clip 61 and the tank truck in sequence, and the sampling is completed.

[0053] Sampling operation steps using a sealed sampling bottle and not connected to the gas phase port of the tank truck:

[0054] The operator touches the human body static electricity release button 64 with hand, the audible alarm of the static electricity alarm 62 stops, and the visual alarm changes from yellow to green; then close all the valves on the sampling system; connect the static electricity clamp 61 to the grounding end of the tanker to release the static electricity of the tanker until the static electricity alarm 62 stops alarming; connect the liquid-phase quick connector 2 to the liquid-phase interface of the tanker; open the sampling discharge valve 31; after observing that there is liquid in the glass sampling liquid level gauge 32, install the airtight sampling bottle 421 on the sampling system; open the feed valve 423, the discharge valve 424, and the aggregate valve 416, and the material reaches inside the airtight sampling bottle 421; the material for rinsing the airtight sampling bottle 421 is introduced into the liquid material collection tank 412 through the aggregate branch 415; after obtaining a suitable sample, close the feed valve 423 and the discharge valve 424, and remove the airtight sampling bottle 421. Close the liquid-phase quick connector 2 in sequence, and open the bypass valve 425, the aggregate valve 416, the gas cylinder valve 511, the gas-phase balance valve 531, and the connection valve 523 to purge all the materials in the sampling system pipeline into the liquid material collection tank 412; after observing that there is no liquid in the glass sampling liquid level gauge 32, close the aggregate valve 416 and the sampling discharge valve 31; open the collection tank valve 414, the material return valve, and the liquid-phase quick connector 2 to transport the materials in the liquid material collection tank 412 into the tanker for recovery; after observing that there is no liquid in the glass sampling liquid level gauge 32, close the collection tank valve 414, the liquid-phase quick connector 2, and all the valves on the sampling system; disconnect the connections of the liquid-phase quick connector 2 and the static electricity clamp 61 with the tanker in sequence, and this sampling is completed.

[0055] In summary, the tanker sampling system provided by the present utility model can be used for pressurized and atmospheric sampling of tankers, and whether to connect the gas phase port of the tanker can be selected according to needs, improving the flexibility and convenience of use, meeting different tanker sampling requirements, and at the same time can be used for sampling with different sampling bottles, solving the limitation of the sampling bottle on the sampling operation, with strong practicability and wide application range. The circulating sample liquid and the rinsing sample liquid during the sampling process can be recycled into the tanker, avoiding the need for sampling personnel to climb to the top of the tanker for operation, ensuring the safety of the sampling personnel during the sampling process, and ensuring that there is no sample liquid residue in the pipeline, avoiding cross-contamination between the sample materials caused by the residual sample liquid, and ensuring the accuracy and representativeness of the sampling.

[0056] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. All equivalent changes and modifications made according to the scope of the present utility model should still fall within the scope covered by the present utility model.

Claims

1. A tank truck sampling system, characterized in that: include: A gas phase quick interface (1), the gas phase quick interface (1) being detachably connected to the gas phase interface of the tank truck; A liquid phase quick interface (2), wherein the liquid phase quick interface (2) is detachably connected to the liquid phase interface of the tank truck; A sampling pipeline (3), wherein the sampling pipeline (3) is provided with a sampling discharge valve (31) and a sampling branch (4), wherein the sampling discharge valve (31) is arranged close to the liquid phase quick interface (2), and the sampling branch (4) is provided with a sampling bottle connected thereto; A purge pipeline (5), the purge pipeline (5) being provided with a purge gas bottle (51), a purge branch (52) and a material return branch (53) connected to the purge gas bottle (51), and a material feeding pipeline (54) connecting the purge branch (52) and the material return branch (53); The end of the sampling pipeline (3) is connected to the purge branch (52), the end of the purge branch (52) is connected to the gas phase quick interface (1), and the end of the material return branch (53) is connected to the liquid phase quick interface (2).

2. The tank truck sampling system according to claim 1, characterized in that: The purge branch (52) is provided with a gas phase shut-off valve (521), a jet pump (522), and a connecting valve (523) which are connected in sequence; the gas phase shut-off valve (521) is arranged close to the gas phase quick interface (1); and the jet pump (522) is connected to the end of the sampling pipeline (3).

3. The tank truck sampling system according to claim 1, characterized in that: The material return branch (53) is provided with a gas phase balance valve (531) and a pipeline pressure gauge (532) arranged close to the purge gas bottle (51), the purge gas bottle (51) is provided with a gas bottle valve (511), and the material feeding pipeline (54) is provided with a material feeding valve (541).

4. The tank truck sampling system according to claim 1, characterized in that: The sampling branch (4) comprises an open branch (41) and a closed branch (42), the open branch (41) being connected in parallel to the sampling pipeline (3), and the closed branch (42) being connected in series to the sampling pipeline (3); The open branch (41) is located between the sampling and discharging valve (31) and the closed branch (42).

5. The tank truck sampling system according to claim 4, characterized in that: The open branch (41) is provided with an on-site sampling port (411) and a liquid material collection tank (412) which are connected to the sampling pipeline (3); the on-site sampling port (411) is located above the liquid material collection tank (412); The on-site sampling port (411) is provided with a sampling valve (413), and the liquid material collecting tank (412) is provided with a collecting tank valve (414).

6. The tank truck sampling system according to claim 5, characterized in that: The open branch (41) is further provided with a material collection branch (415) connected to the purge branch (52), and the end of the material collection branch (415) is arranged above the liquid material collection tank (412); The material collecting branch line (415) is provided with a material collecting valve (416).

7. The tank truck sampling system according to claim 4, characterized in that: The closed branch (42) is provided with a closed sampling bottle (421) connected in series with the sampling pipeline (3), and a bypass branch (422) connected in parallel with the closed sampling bottle (421); The feeding end of the sealed sampling bottle (421) is provided with a feeding valve (423), the discharging end is provided with a discharge valve (424), and the bypass branch (422) is provided with a bypass valve (425).

8. The tank truck sampling system according to claim 7, characterized in that: The closed branch (42) is further provided with a flushing circulation pump (426) connected in series with the sampling pipeline (3); the flushing circulation pump (426) is provided with an air source pipeline (427) connected to the purge pipeline (5); and the air source pipeline (427) is provided with an air source valve (428).

9. The tank truck sampling system according to claim 1, characterized in that: The sampling pipeline (3) is also provided with a sampling liquid level meter (32), and the sampling liquid level meter (32) is located between the sampling discharge valve (31) and the sampling branch (4).

10. The tank truck sampling system according to claim 1, characterized in that: It also includes a grounding branch (6), wherein the grounding branch (6) is provided with an electrostatic clip (61), an electrostatic alarm (62), an on-site grounding terminal (63), and a human body electrostatic release button (64) which are connected in sequence; The electrostatic clip (61) is detachably connected to the grounding terminal of the tank truck.

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