Oil sample switching device

Abstract

The utility model discloses an oil sample switching device. In an existing verification mode, oil samples need to be replaced frequently, the workload is large, and the efficiency is low, air ports of a plurality of oil cylinders are connected into oil cylinder pressurizing ports corresponding to a control module through air pipes respectively, and oil outlets of the plurality of oil cylinders are connected into oil cylinder oil inlets corresponding to the control module through oil conveying pipes respectively. Each oil conveying pipe is provided with a three-way connector and is divided into a first oil conveying pipe and a second oil conveying pipe, the first oil conveying pipe and the second oil conveying pipe are connected into a fourth oil conveying pipe and a third oil conveying pipe in parallel respectively, and the third oil conveying pipe and the fourth oil conveying pipe are connected into a portable chromatograph and an online monitoring device respectively. Electromagnetic valves are arranged on the first oil conveying pipes and the second oil conveying pipes, and work of the corresponding oil cylinders is completed by switching the electromagnetic valves. According to the utility model, a plurality of on-line monitoring devices can be verified at the same time, the reference oil sample does not need to be frequently replaced in the verification process, the workload is reduced, and the verification efficiency is high.

Description

Technical Field

[0001] The utility model relates to calibration equipment for an on-line monitoring device for dissolved gas in transformer oil, in particular to an oil sample switching device. Background Art

[0002] At present, the main process of the laboratory online monitoring device calibration method is as follows: first, reference oil samples of different concentrations are configured through a mixer, and after the configuration is completed, they are transferred to the oil cylinder, the oil inlet of the online monitoring device to be inspected is connected to the oil outlet of the oil cylinder, and the oil cylinder is pressurized with a compressed air cylinder or an air pump to maintain a stable pressure so that the reference oil sample can flow out; at the same time, the reference oil sample in the oil cylinder is sampled for offline analysis, and compared and evaluated with the detection data of the online monitoring device to evaluate the measurement error of the online monitoring device. However, manual replacement is required when replacing reference oil samples of different concentrations, which is cumbersome, labor-intensive and inefficient, and cannot meet the calibration needs of various types of online monitoring devices. Utility Model Content

[0003] In order to solve the technical problems of frequent replacement of reference oil samples, large workload and low efficiency in the existing laboratory calibration process, the utility model provides an oil sample switching device, which highly integrates the oil cylinder, air pump, portable chromatograph and online monitoring device through the laying of several oil pipes, multiple three-way joints and solenoid valves. During calibration, there is no need to frequently disassemble and replace the reference oil samples. The calibration can be automatically completed through software control to improve the calibration efficiency, and multiple online monitoring devices can be calibrated at the same time.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical solution: an oil sample switching device, including an oil cylinder, a control module, a portable chromatograph and an online monitoring device, wherein the oil cylinder includes a low-concentration oil cylinder, a medium-concentration oil cylinder and a high-concentration oil cylinder which are independent of each other, and each oil cylinder is provided with an air port and an oil outlet;

[0005] The control module is provided with a low-concentration oil cylinder pressurization port, a low-concentration oil cylinder oil inlet port, a medium-concentration oil cylinder pressurization port, a medium-concentration oil cylinder oil inlet port, a high-concentration oil cylinder pressurization port and a high-concentration oil cylinder oil inlet port;

[0006] The oil outlet of the low-concentration oil cylinder is connected to the oil inlet of the low-concentration oil cylinder on the control module through an oil pipeline, and the oil pipeline is divided into a first oil pipeline and a second oil pipeline through a three-way joint, and a one-way valve and a solenoid valve are provided on the first oil pipeline and the second oil pipeline; the air port of the low-concentration oil cylinder is connected to the low-concentration oil cylinder pressurization port on the control module through an air pipe, and a pressure sensor, a vent valve and a solenoid valve are provided on the pipeline;

[0007] The oil outlet of the medium-concentration oil cylinder is connected to the oil inlet of the medium-concentration oil cylinder on the control module through an oil pipeline, and the oil pipeline is divided into a first oil pipeline and a second oil pipeline through a three-way joint, and a one-way valve and a solenoid valve are provided on the first oil pipeline and the second oil pipeline; the air port of the medium-concentration oil cylinder is connected to the medium-concentration oil cylinder pressurization port on the control module through an air pipe, and a pressure sensor, a vent valve and a solenoid valve are provided on the pipeline;

[0008] The oil outlet of the high-concentration oil cylinder is connected to the oil inlet of the high-concentration oil cylinder on the control module through an oil pipeline, and the oil pipeline is divided into a first oil pipeline and a second oil pipeline through a three-way joint, and a one-way valve and a solenoid valve are provided on the first oil pipeline and the second oil pipeline; the air port of the high-concentration oil cylinder is connected to the high-concentration oil cylinder pressurization port on the control module through an air pipe, and a pressure sensor, a vent valve and a solenoid valve are provided on the pipeline;

[0009] Each first oil pipeline is connected in parallel to the fourth oil pipeline through a three-way joint, each second oil pipeline is connected in parallel to the third oil pipeline through a three-way joint, and the third oil pipeline is divided into two branches through the three-way joint, one branch is used to connect the portable chromatograph, and the other branch is equipped with an oil extraction valve connected to the manual oil extraction port; the fourth oil pipeline is provided with a flow meter and connected to the online monitoring device, and is connected to the oil cylinder of the corresponding concentration through the corresponding solenoid valve switching channel;

[0010] The pressurized port pipeline of each oil cylinder is connected in parallel to the air pump through a three-way joint, and the corresponding oil cylinder is switched to work through the corresponding solenoid valve control.

[0011] The utility model transfers prepared reference oil samples of different concentrations to a low-concentration oil cylinder, a medium-concentration oil cylinder and a high-concentration oil cylinder respectively, switches the solenoid valve to select the corresponding oil cylinder to output the oil sample to a portable chromatograph and an online monitoring device, detects and analyzes the same oil sample through the portable chromatograph and the online monitoring device, evaluates the performance of the device, and the entire calibration process does not require frequent replacement of the oil cylinder, has a small workload and high efficiency, and can realize automatic calibration.

[0012] When the utility model is calibrated, the gas ports and oil outlets on the low-concentration oil cylinder, the medium-concentration oil cylinder and the high-concentration oil cylinder are connected to the corresponding oil cylinder pressurization port and oil inlet on the control module through the gas pipe and the oil pipeline respectively. The oil cylinder is selected according to the demand, and the oil outlets of the low, medium and high-concentration oil cylinders are divided into two branches, the first oil pipeline and the second oil pipeline, through the oil pipeline through the three-way joint for output, and are simultaneously transported to the portable chromatograph and the online monitoring device for detection and analysis. The gas ports of the low, medium and high-concentration oil cylinders are all connected to the air pump, and the air outlet pipeline of the air pump can pressurize each independent oil cylinder. The pressure in the oil cylinder can be adjusted through the pressure sensor on the pipeline, and the gas can also be vented through the vent valve on the pipeline.

[0013] As a further improvement and supplement to the above technical solution, the utility model adopts the following technical measures:

[0014] The control module is provided with an offline port, and a branch of the third oil pipeline is connected to the oil inlet of the portable chromatograph through the offline port. The portable chromatograph detects and analyzes the reference oil samples in the low-concentration oil cylinder, the medium-concentration oil cylinder and the high-concentration oil cylinder and obtains reference data. A glass syringe can also be used to adjust the flow rate through the regulating valve on the control module to obtain oil samples at the manual oil extraction port, and detect and analyze them through the laboratory gas chromatograph.

[0015] The control module is provided with a calibration oil outlet, and the fourth oil pipeline is connected to the oil inlet end of the online monitoring device through the calibration oil outlet.

[0016] The control module is provided with a data acquisition system, in which a switch, an industrial computer and a router are arranged. The portable chromatograph and the online monitoring device are connected to the network cable interface of the control module through a network cable, and communicate with the data acquisition system. The online monitoring device and the portable chromatograph can be controlled and operated simultaneously through the switch and the industrial computer. The data acquisition system can also receive the detection data of the online monitoring device and the portable chromatograph in real time, and store the detection data in the industrial computer, and automatically evaluate the data.

[0017] The control module is provided with a control screen, and the control screen is provided with a rain cover.

[0018] The air outlet of the air pump is provided with a switching valve, and the air generated and stored by the air pump is pressurized to each independent oil cylinder by controlling the switching valve.

[0019] The control module is provided with a purge port.

[0020] The capacity of the low-concentration oil cylinder, the medium-concentration oil cylinder and the high-concentration oil cylinder are all 15 L or 30 L. Different volumes of oil samples are prepared according to the performance requirements of the device to meet different calibration requirements.

[0021] The outer diameters of the gas pipe, the oil pipe, the first oil pipe, the second oil pipe, the third oil pipe and the fourth oil pipe are all 6 mm, and the inner diameters of the interfaces of the three-way joint and the one-way valve are all 6 mm. The oil pipe with an outer diameter of 6 mm and the joint and interface with an inner diameter of 6 mm are relatively common, economical and practical, and meet the requirements of relevant calibration standards.

[0022] The gas pipe, oil pipe, first oil pipe, second oil pipe, third oil pipe and fourth oil pipe are all oil-resistant polymer pipes. The oil pipe made of oil-resistant polymer material can meet the needs of long-term oil transportation, and has stable performance and corrosion resistance.

[0023] The utility model connects low-concentration oil cylinders, medium-concentration oil cylinders, high-concentration oil cylinders, control modules, portable chromatographs and online monitoring devices through air pipes and oil pipelines to achieve high integration. Each independent oil cylinder is split through a three-way joint and simultaneously transported to a portable chromatograph and an online monitoring device for detection and analysis. The detection results of both are evaluated to judge the performance of the device. Multiple online monitoring devices can be calibrated at the same time. During the calibration process, it is no longer necessary to frequently replace reference oil samples, which reduces the workload and improves the calibration efficiency. In addition, the utility model can automatically complete the calibration through software control, which is practical and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a structural block diagram of the oil sample switching device of the utility model;

[0026] Figure 2 This is a schematic diagram of the structure of the oil sample switching device of the utility model;

[0027] Figure 3 This is a structural schematic diagram of a control module of the oil sample switching device of the utility model;

[0028] Figure 4 This is a schematic diagram of the structure of the control module of the oil sample switching device of the utility model after the outer shell is removed;

[0029] In the figure: 1. oil cylinder, 1-1. low-concentration oil cylinder, 1-2. medium-concentration oil cylinder, 1-3. high-concentration oil cylinder, 11. air pipe, 12. oil pipeline;

[0030] 2. Control module, 21. Pressure sensor, 22. Vent valve, 23. Check valve, 24. Solenoid valve, 25. Three-way connector, 26. Flow meter, 27. Oil extraction valve, 28. Air pump, 29. Switching valve, 30. Manual oil extraction port, 31. Purge port, 32. Check oil outlet, 33. Low-concentration oil cylinder pressurization port, 34. Low-concentration oil cylinder oil inlet, 35. Medium-concentration oil cylinder pressurization port, 36. Medium-concentration oil cylinder oil inlet, 37. High-concentration oil cylinder pressurization port, 38. High-concentration oil cylinder oil inlet, 39. Offline port, 40. Regulating valve, 41. Network cable interface, 42. Control panel, 43. Data acquisition system, 44. First oil pipeline, 45. Second oil pipeline, 46. Third oil pipeline, 47. Fourth oil pipeline;

[0031] 3. Portable chromatograph;

[0032] 4.Online monitoring device. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] like Figure 1-4 As shown, the oil sample switching device of the utility model is composed of an oil cylinder 1, a control module 2, a portable chromatograph 3 and an online monitoring device 4. The oil cylinder 1 is a low-concentration oil cylinder 1-1, a medium-concentration oil cylinder 1-2 and a high-concentration oil cylinder 1-3 which are independent of each other, and each oil cylinder is provided with an air port and an oil outlet.

[0035] The control module 2 is provided with a low-concentration oil cylinder pressurizing port 33 , a low-concentration oil cylinder oil inlet 34 , a medium-concentration oil cylinder pressurizing port 35 , a medium-concentration oil cylinder oil inlet 36 , a high-concentration oil cylinder pressurizing port 37 and a high-concentration oil cylinder oil inlet 38 .

[0036] The oil outlet of the low-concentration oil cylinder 1-1 is connected to the low-concentration oil cylinder oil inlet 34 on the control module 2 through the oil pipe 12. The oil pipe 12 is divided into a first oil pipe 44 and a second oil pipe 45 through a three-way joint 25. The first oil pipe 44 and the second oil pipe 45 are both provided with a one-way valve 23 and a solenoid valve 24. The air port of the low-concentration oil cylinder 1-1 is connected to the low-concentration oil cylinder pressurization port 33 on the control module 2 through the air pipe 11. A pressure sensor 21, a vent valve 22 and a solenoid valve 24 are provided on the pipeline.

[0037] The oil outlet of the medium-concentration oil cylinder 1-2 is connected to the medium-concentration oil cylinder oil inlet 36 on the control module 2 through the oil pipeline 12. The oil pipeline 12 is divided into a first oil pipeline 44 and a second oil pipeline 45 through a three-way joint 25. The first oil pipeline 44 and the second oil pipeline 45 are both provided with a one-way valve 23 and a solenoid valve 24. The air port of the medium-concentration oil cylinder 1-2 is connected to the medium-concentration oil cylinder pressurization port 35 on the control module 2 through the air pipe 11. A pressure sensor 21, a vent valve 22 and a solenoid valve 24 are provided on the pipeline.

[0038] The oil outlet of the high-concentration oil cylinder 1-3 is connected to the high-concentration oil cylinder oil inlet 38 on the control module 2 through the oil pipeline 12. The oil pipeline 12 is divided into a first oil pipeline 44 and a second oil pipeline 45 through a three-way joint 25. The first oil pipeline 44 and the second oil pipeline 45 are both provided with a one-way valve 23 and a solenoid valve 24. The air port of the high-concentration oil cylinder 1-3 is connected to the high-concentration oil cylinder pressurization port 37 on the control module 2 through the air pipe 11. A pressure sensor 21, a vent valve 22 and a solenoid valve 24 are provided on the pipeline.

[0039] Each first oil pipeline 44 is connected in parallel to the fourth oil pipeline 47 via the three-way joint 25, and each second oil pipeline 45 is connected in parallel to the third oil pipeline 46 via the three-way joint 25. The third oil pipeline 46 is provided with a flow meter 26 and is divided into two branches through the three-way joint 25, one branch is used to connect the portable chromatograph 3, and the other branch is equipped with an oil extraction valve 27 connected to the manual oil extraction port 30. The fourth oil pipeline 47 is provided with a flow meter 26 and connected to the online monitoring device 4, and the corresponding concentration oil cylinder is connected through the corresponding electromagnetic valve 24 switching channel, and the reference oil sample is output to the portable chromatograph 3 and the online monitoring device 4. Each independent oil cylinder pressurization port pipeline is connected in parallel to the air pump 28 through the three-way joint 25, and the corresponding oil cylinder is switched to work through the corresponding electromagnetic valve 24.

[0040] The air outlet of the air pump 28 is provided with a switching valve 29, and the air generated and stored by the air pump 28 is pressurized for each independent cylinder by controlling the switching valve 29. The pressure sensor 21 on the pipeline can adjust the pressure in the cylinder, and the gas can also be emptied through the vent valve 22 on the pipeline.

[0041] As an embodiment of the utility model: the control module 2 is provided with an offline port 39, a check oil outlet 32 ​​and a network cable interface 41, a branch of the third oil pipeline 46 is connected to the oil inlet end of the portable chromatograph through the offline port 39, and the fourth oil pipeline is connected to the oil inlet end of the online monitoring device through the check oil outlet. The portable chromatograph 3 detects and analyzes the reference oil samples in the low-concentration oil cylinder 1-1, the medium-concentration oil cylinder 1-2 and the high-concentration oil cylinder 1-3 and obtains reference data. A glass syringe can also be used to adjust the flow rate through the regulating valve 40 to obtain oil samples at the manual oil extraction port 30, and detect and analyze them in the laboratory gas chromatograph. The purge port 31 on the control module 2 can be connected to the check oil pipeline to purge and empty the residual oil in the pipeline, and can also be connected to the oil cylinder 1 separately to empty the residual oil in the cylinder into a waste oil barrel.

[0042] As another embodiment of the utility model: the control module 2 is provided with a control panel 42 and a data acquisition system 43, the control panel 42 is provided with a rain cover, and a switch, an industrial computer and a router are arranged in the data acquisition system 43. The portable chromatograph 3 and the online monitoring device 4 are connected to the network cable interface 41 of the control module 2 through a network cable, and the online monitoring device 4 and the portable chromatograph 3 can be controlled and operated simultaneously through the switch and the industrial computer, and the data acquisition system 43 can also receive the detection data of the online monitoring device 4 and the portable chromatograph 3 in real time, and store the detection data in the industrial computer, and automatically evaluate the data.

[0043] As another embodiment of the utility model: the capacity of the low-concentration oil cylinder 1-1, the medium-concentration oil cylinder 1-2 and the high-concentration oil cylinder 1-3 are all 15L or 30L, the outer diameters of the air pipe 11, the oil pipe 12, the first oil pipe 44, the second oil pipe 45, the third oil pipe 46 and the fourth oil pipe 47 are all 6mm, and the inner diameters of the interfaces of the three-way joint 25 and the one-way valve 23 are all 6mm. At the same time, the air pipe 11, the oil pipe 12, the first oil pipe 44, the second oil pipe 45, the third oil pipe 46 and the fourth oil pipe 47 are all oil-resistant polymer pipes.

[0044] The entire oil sample switching device no longer needs to frequently replace the reference oil sample during the calibration process, reducing the workload. When the utility model is combined with the control software, it only needs to remotely control the opening and closing of the solenoid valve as required to select the corresponding path to work and realize automatic calibration. During calibration, it is only necessary to connect the low-concentration oil cylinder, medium-concentration oil cylinder, high-concentration oil cylinder, control module, portable chromatograph and online monitoring device through the air pipe and the oil pipeline. Each independent oil cylinder is diverted through a three-way joint and transported to the portable chromatograph and the online monitoring device for detection and analysis respectively. The detection results of the two are evaluated to judge the performance of the device. Multiple online monitoring devices can also be calibrated at the same time to improve the calibration efficiency.

[0045] It is obvious that a person skilled in the art can easily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. An oil sample switching device, comprising an oil cylinder (1), a control module (2), a portable chromatograph (3) and an online monitoring device (4), wherein the oil cylinder (1) comprises a low-concentration oil cylinder (1-1), a medium-concentration oil cylinder (1-2) and a high-concentration oil cylinder (1-3) which are independent of each other, each oil cylinder being provided with an air port and an oil outlet, and characterized in that: The control module (2) is provided with a low-concentration oil cylinder pressurizing port (33), a low-concentration oil cylinder oil inlet (34), a medium-concentration oil cylinder pressurizing port (35), a medium-concentration oil cylinder oil inlet (36), a high-concentration oil cylinder pressurizing port (37) and a high-concentration oil cylinder oil inlet (38); The oil outlet of the low-concentration oil cylinder (1-1) is connected to the low-concentration oil cylinder oil inlet (34) on the control module (2) through an oil pipeline (12); the oil pipeline (12) is divided into a first oil pipeline (44) and a second oil pipeline (45) through a three-way joint (25); both the first oil pipeline (44) and the second oil pipeline (45) are provided with a one-way valve (23) and a solenoid valve (24); the air port of the low-concentration oil cylinder (1-1) is connected to the low-concentration oil cylinder pressurization port (33) on the control module (2) through an air pipe (11); and a pressure sensor (21), a vent valve (22) and a solenoid valve (24) are provided on the pipeline; The oil outlet of the medium-concentration oil cylinder (1-2) is connected to the medium-concentration oil cylinder oil inlet (36) on the control module (2) through an oil pipeline (12); the oil pipeline (12) is divided into a first oil pipeline (44) and a second oil pipeline (45) through a three-way joint (25); both the first oil pipeline (44) and the second oil pipeline (45) are provided with a one-way valve (23) and a solenoid valve (24); the air port of the medium-concentration oil cylinder (1-2) is connected to the medium-concentration oil cylinder pressurization port (35) on the control module (2) through an air pipe (11); and a pressure sensor (21), a vent valve (22) and a solenoid valve (24) are provided on the pipeline; The oil outlet of the high-concentration oil cylinder (1-3) is connected to the high-concentration oil cylinder oil inlet (38) on the control module (2) through an oil pipeline (12); the oil pipeline (12) is divided into a first oil pipeline (44) and a second oil pipeline (45) through a three-way joint (25); both the first oil pipeline (44) and the second oil pipeline (45) are provided with a one-way valve (23) and a solenoid valve (24); the air port of the high-concentration oil cylinder (1-3) is connected to the high-concentration oil cylinder pressurization port (37) on the control module (2) through an air pipe (11); and a pressure sensor (21), a vent valve (22) and a solenoid valve (24) are provided on the pipeline; Each first oil pipeline (44) is connected in parallel to a fourth oil pipeline (47) via a three-way joint, each second oil pipeline (45) is connected in parallel to a third oil pipeline (46) via a three-way joint, the third oil pipeline (46) is divided into two branches via a three-way joint (25), one branch is used to connect to a portable chromatograph (3), and the other branch is equipped with an oil extraction valve (27) and connected to a manual oil extraction port (30); the fourth oil pipeline (47) is provided with a flow meter (26) and connected to an online monitoring device (4), and is connected to an oil cylinder of a corresponding concentration through a corresponding solenoid valve (24) switching channel; The pressurizing port pipeline of each oil cylinder is connected in parallel to the air pump (28) through a three-way joint (25), and the corresponding oil cylinder is switched to work through the corresponding solenoid valve (24).

2. The oil sample switching device according to claim 1, characterized in that: The control module (2) is provided with an offline port (39), and a branch of the third oil pipeline (46) is connected to the oil inlet end of the portable chromatograph (3) through the offline port (39).

3. The oil sample switching device according to claim 1, characterized in that: The control module (2) is provided with a calibration oil outlet (32), and the fourth oil delivery pipe (47) is connected to the oil inlet end of the online monitoring device (4) through the calibration oil outlet (32).

4. The oil sample switching device according to claim 1, characterized in that: The control module (2) is provided with a data acquisition system (43), and a switch, an industrial computer and a router are arranged in the data acquisition system (43). The portable chromatograph (3) and the online monitoring device (4) are connected to the network cable interface (41) of the control module (2) via a network cable, and perform data communication with the data acquisition system (43).

5. The oil sample switching device according to claim 4 is characterized in that: The control module (2) is provided with a control screen (42), and the control screen (42) is provided with a rain cover.

6. The oil sample switching device according to claim 1, characterized in that: The air outlet of the air pump (28) is provided with a switching valve (29), and the air generated and stored by the air pump (28) is pressurized in each independent oil cylinder by controlling the switching valve (29).

7. The oil sample switching device according to claim 1, characterized in that: The control module (2) is provided with a purge port (31).

8. The oil sample switching device according to claim 1, characterized in that: The capacity of the low-concentration oil cylinder (1-1), the medium-concentration oil cylinder (1-2) and the high-concentration oil cylinder (1-3) are all 15L or 30L.

9. The oil sample switching device according to claim 1, characterized in that: The outer diameters of the air pipe (11), the oil pipe (12), the first oil pipe (44), the second oil pipe (45), the third oil pipe (46) and the fourth oil pipe (47) are all 6 mm, and the inner diameters of the interfaces of the three-way connector (25) and the one-way valve (23) are all 6 mm.

10. The oil sample switching device according to claim 1, characterized in that: The air pipe (11), the oil pipe (12), the first oil pipe (44), the second oil pipe (45), the third oil pipe (46) and the fourth oil pipe (47) are all oil-resistant polymer pipes.

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