Special-shaped pipeline and preparation method thereof

Abstract

The invention relates to the technical field of pipelines, in particular to a special-shaped pipeline and a preparation method thereof.The special-shaped pipeline comprises a pipe body, the outer portion of the pipe body is fixedly connected with multiple sets of reinforcing plates, and one end of the pipe body is fixedly connected with a connecting outer convex ring; the pipe body is made of metal, inorganic nonmetal, organic materials (such as PE, PP, PVC, ABS, PET, PBT, PETG, PA and the like), composite materials of the materials and the like. The weight part of the organic material is 65-95 parts; pTFE (polytetrafluoroethylene); 1-5 parts of a mixture; 5-35 parts of crystalline silicon powder; 1-5 parts of a silane coupling agent; 1 to 5 parts of an antioxidant DSTDP; 1 to 5 parts of an ultraviolet light absorber uv531; 0.5 to 2 parts of paraffin wax; 0.5 to 2 parts of stearic acid; and 1-5 parts of color master batch. The special-shaped pipeline can be used in the fields of water supply, drainage, heating, electric power, communication, fuel gas and the like. The problems that an existing municipal cylindrical pipeline is weak in anti-pressure capacity, concentrated in stress, poor in adaptability and the like can be solved in a targeted mode.

Description

Technical Field

[0001] This invention relates to the field of pipeline technology, and in particular to an irregularly shaped pipeline and its preparation method. Background Technology

[0002] In municipal pipeline systems, pipelines serve as core infrastructure for transporting sewage, rainwater, water supply, electricity, and communications. They must be buried underground for extended periods, enduring multiple forces such as backfill soil compression, soil settlement, and groundwater erosion. Their structural stability and compressive strength directly determine the system's operational reliability. Currently, most mainstream municipal pipelines on the market adopt traditional cylindrical structures, primarily using materials such as ordinary polyethylene (PE), polypropylene (PP), or concrete. While these structures are simple and provide basic transport functions, they suffer from significant deficiencies in compressive strength and structural adaptability, making them unsuitable for long-term use in deep-buried, high-load scenarios.

[0003] From a structural perspective, traditional cylindrical pipes have uniformly curved walls. The common PE and PP materials used in these pipes are prone to stress concentration under load. When buried at a depth of 3 meters or more, the vertical pressure from the backfill soil concentrates on the curved area at the top of the pipe. Since cylindrical structures lack effective stress dispersion mechanisms, they can only resist pressure through the thickness of the pipe wall itself, making them susceptible to radial deformation, dents, and even rupture. Summary of the Invention

[0004] To address the technical problem that the vertical compressive force generated by backfill soil in existing pipelines is concentrated on the arc-shaped area at the top of the pipeline, and the cylindrical structure lacks an effective stress dispersion mechanism, it can only resist the pressure through the thickness of the pipe wall itself, which makes the pipeline prone to radial deformation, dents or even rupture, this invention provides an irregularly shaped drainage pipe and its preparation method.

[0005] The technical solution adopted in this invention is: an irregularly shaped pipe, including a pipe body, with multiple sets of reinforcing plates fixedly connected to the outside of the pipe body, and a connecting external protruding ring fixedly connected to one end of the pipe body, the shape of the pipe body being an irregular shape or a regular polygonal structure.

[0006] In one embodiment, the inner cavity of the tube is circular, elliptical, or polygonal, and the tube is teardrop-shaped or spindle-shaped.

[0007] The embodiments in this article are implemented using organic ABS material.

[0008] In one embodiment, the tube body is composed of the following raw materials in parts by weight:

[0009] ABS: 65-95 parts;

[0010] PTFE; 1-5 parts;

[0011] 5-35 parts of crystalline silicon powder;

[0012] 1-5 parts of silane coupling agent;

[0013] Antioxidant DSTDP 1-5 parts;

[0014] UV absorber uv531: 1-5 parts;

[0015] Paraffin wax 0.5 to 2 parts;

[0016] Stearic acid 0.5–2 parts;

[0017] 1-5 parts of color masterbatch.

[0018] In one embodiment, the tube body is composed of the following raw materials in parts by weight:

[0019] 65 ABS samples;

[0020] 0.2 parts PTFE;

[0021] 25 parts of crystalline silicon powder;

[0022] 4.5 parts of silane coupling agent;

[0023] Antioxidant DSTDP 1.5 parts;

[0024] UV absorber UV531, 1.5 parts;

[0025] 1 part stearic acid;

[0026] Three portions of color masterbatch.

[0027] In one embodiment, the tube body is composed of the following raw materials in parts by weight:

[0028] 70 ABS units;

[0029] 0.3 parts PTFE;

[0030] 20 parts of crystalline silicon powder;

[0031] 4.0 parts of silane coupling agent;

[0032] Antioxidant DSTDP 1.5 parts;

[0033] UV absorber UV531, 1.5 parts;

[0034] 1 part stearic acid;

[0035] 3 portions of color masterbatch

[0036] In one embodiment, the tube body is composed of the following raw materials in parts by weight:

[0037] 75 ABS samples;

[0038] 0.4 parts PTFE;

[0039] 15 parts of crystalline silicon powder;

[0040] 3 parts silane coupling agent;

[0041] Antioxidant DSTDP 1.5 parts;

[0042] UV absorber UV531, 1.5 parts;

[0043] 1 part stearic acid;

[0044] Three portions of color masterbatch.

[0045] In one embodiment, the tube body is composed of the following raw materials in parts by weight:

[0046] 85 ABS samples;

[0047] 0.6 parts PTFE;

[0048] 5 parts of crystalline silicon powder;

[0049] 2 parts of silane coupling agent;

[0050] Antioxidant DSTDP 1.5 parts;

[0051] UV absorber UV531, 1.5 parts;

[0052] 1 part stearic acid;

[0053] Three portions of color masterbatch.

[0054] In one embodiment, a method for preparing an irregularly shaped pipe specifically includes the following steps:

[0055] Step 1: Weigh the raw materials according to the specified weight proportions, mix and stir them evenly, and set aside.

[0056] Step two: Heating is performed by heating the head and main body sections of the screw extruder to the set temperature until a constant temperature is reached and maintained within ±5℃.

[0057] Step 3: Start the screw extruder and feed at a low speed of 5-10 rpm. After running for 5-10 minutes without any abnormalities, gradually increase the speed to 75%-90% of the normal speed. After holding for another 5-10 minutes without any abnormalities, increase the speed to the normal speed and maintain normal feeding.

[0058] Step 4, pipe shaping and cooling: After the pipe blank is extruded through the die head, it enters the cavity composed of the water jacket and the module. The negative pressure vacuum on the module shapes and cools it. The forming machine rotates continuously, pulling the shaped pipe out onto the pipe support.

[0059] Step 5: Pipe cutting and transportation. Cut the cooled and shaped pipes according to the length requirements. The cutting surface should be perpendicular to the pipe axis. Cut neatly and remove any burrs.

[0060] Step six: The cut and trimmed pipes are neatly stacked on the transport vehicle and transported to the storage yard.

[0061] The beneficial effects of this invention are as follows: Compared with the prior art, the irregularly shaped drainage pipe of this invention can specifically solve the problems of weak compressive strength, stress concentration, and poor adaptability of existing municipal cylindrical pipes. It adopts a combination design of composite materials with specific proportions and arched reinforcing plates, and the ring stiffness is much higher than that of traditional cylindrical pipes. It can easily resist the extrusion of backfill soil buried deep underground, and has a high safety factor. The non-cylindrical structure of the pipe body, combined with the reinforcing plate, can convert part of the vertical extrusion force into axial force and evenly disperse the stress through a specific path, avoiding the stress concentration problem at the top of traditional cylindrical pipes. Under extrusion, the stress peak is much lower than the material yield strength. At the same time, the specific components work synergistically to improve the pipe material's resistance to acid and alkali corrosion and self-lubrication, reduce soil friction and wear, and have excellent anti-aging and structural stability. The long-term attenuation rate of support force is low. It avoids the defects of traditional concrete pipes, such as large weight and poor crack resistance, and solves the problem of insufficient stiffness of ordinary plastic pipes. It meets the long-term high-strength and high-durability requirements of municipal pipelines, and reduces maintenance costs and the risk of waterlogging. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the structure of the present invention;

[0063] Figure 2 This is a schematic diagram of the tube structure in this invention. Figure 1 ;

[0064] Figure 3 This is a schematic diagram of the tube structure in this invention. Figure 2 ;

[0065] Figure 4 This is a schematic diagram of the tube structure in this invention. Figure 3 ;

[0066] Figure 5 This is a schematic diagram of the tube structure in this invention. Figure 4 ;

[0067] Figure 6 This is a schematic diagram of the tube structure in this invention. Figure 5 .

[0068] The markings in the diagram are: 1. Pipe body; 2. Connecting outer protruding ring; 3. Reinforcing plate. Detailed Implementation

[0069] In the description of this invention, it should be noted that the terms "front", "up", "down", "left", "right", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0070] refer to Figures 1-6 In order to solve the problems existing in the background technology, this application proposes the following technical solution: an irregular drainage pipe, including a pipe body 1, a plurality of reinforcing plates 3 are fixedly connected to the outside of the pipe body 1, a connecting external protruding ring 2 is fixedly connected to one end of the pipe body 1, and the shape of the pipe body 1 is an irregular or regular polygonal structure.

[0071] The inner cavity of the tube 1 is circular, elliptical, or polygonal.

[0072] Among them, pipe body 1 mainly bears external pressure and load, and can also be used in internal pressure pipelines in the fields of water supply, heating and gas supply.

[0073] The tube body 1 is composed of the following raw materials by weight: organic materials (such as PE, PP, PVC, ABS, PET, PBT, PETG, PA, etc.) or their composite materials: 65-95 parts; PTFE: 1-5 parts; crystalline silicon powder: 5-35 parts; silane coupling agent: 1-5 parts; antioxidant DSTDP: 1-5 parts; ultraviolet absorber uv531: 1-5 parts; paraffin wax: 0.5-2 parts; stearic acid: 0.5-2 parts; color masterbatch: 1-5 parts;

[0074] In addition, the material can be one or a combination of inorganic materials, organic materials, metallic materials, and alloy materials.

[0075] The embodiments in this article are implemented using the organic material ABS:

[0076] The tube 1 is composed of the following raw materials in parts by weight:

[0077] ABS: 65-95 parts;

[0078] PTFE; 1-5 parts;

[0079] 5-35 parts of crystalline silicon powder;

[0080] 1-5 parts of silane coupling agent;

[0081] Antioxidant DSTDP 1-5 parts;

[0082] UV absorber uv531: 1-5 parts;

[0083] Paraffin wax 0.5 to 2 parts;

[0084] Stearic acid 0.5–2 parts;

[0085] 1-5 parts of color masterbatch.

[0086] The method for preparing irregularly shaped drainage pipes specifically includes the following steps:

[0087] Step 1: Weigh the raw materials according to the specified weight proportions, mix and stir them evenly, and set aside.

[0088] Step two: Heating is performed by heating the head and main body sections of the screw extruder to the set temperature until a constant temperature is reached and maintained within ±5℃.

[0089] Step 3: Start the screw extruder and feed at a low speed of 5-10 rpm. After running for 5-10 minutes without any abnormalities, gradually increase the speed to 75%-90% of the normal speed. After holding for another 5-10 minutes without any abnormalities, increase the speed to the normal speed and maintain normal feeding.

[0090] Step 4, pipe shaping and cooling: After the pipe blank is extruded through the die head, it enters the cavity composed of the water jacket and the module. The negative pressure vacuum on the module shapes and cools it. The forming machine rotates continuously, pulling the shaped pipe out onto the pipe support.

[0091] Step 5: Pipe cutting and transportation. Cut the cooled and shaped pipes according to the length requirements. The cutting surface should be perpendicular to the pipe axis. Cut neatly and remove any burrs.

[0092] Step six: The cut and trimmed pipes are neatly stacked on the transport vehicle and transported to the storage yard.

[0093] Example 1:

[0094] The tube 1 is composed of the following raw materials in parts by weight:

[0095] 65 ABS samples;

[0096] 0.2 parts PTFE;

[0097] 25 parts of crystalline silicon powder;

[0098] 4.5 parts of silane coupling agent;

[0099] Antioxidant DSTDP 1.5 parts;

[0100] UV absorber UV531, 1.5 parts;

[0101] 1 part stearic acid;

[0102] Three portions of color masterbatch.

[0103] Example 2:

[0104] The tube 1 is composed of the following raw materials in parts by weight:

[0105] 70 ABS units;

[0106] 0.3 parts PTFE;

[0107] 20 parts of crystalline silicon powder;

[0108] 4.0 parts of silane coupling agent;

[0109] Antioxidant DSTDP 1.5 parts;

[0110] UV absorber UV531, 1.5 parts;

[0111] 1 part stearic acid;

[0112] 3 portions of color masterbatch

[0113] Example 3:

[0114] The tube 1 is composed of the following raw materials in parts by weight:

[0115] 75 ABS samples;

[0116] 0.4 parts PTFE;

[0117] 15 parts of crystalline silicon powder;

[0118] 3 parts silane coupling agent;

[0119] Antioxidant DSTDP 1.5 parts;

[0120] UV absorber UV531, 1.5 parts;

[0121] 1 part stearic acid;

[0122] Three portions of color masterbatch.

[0123] Example 4:

[0124] The tube 1 is composed of the following raw materials in parts by weight:

[0125] 85 ABS samples;

[0126] 0.6 parts PTFE;

[0127] 5 parts of crystalline silicon powder;

[0128] 2 parts of silane coupling agent;

[0129] Antioxidant DSTDP 1.5 parts;

[0130] UV absorber UV531, 1.5 parts;

[0131] 1 part stearic acid;

[0132] Three portions of color masterbatch.

[0133] Experimental example:

[0134] First, the pipes in Examples 1 to 4 are produced according to the set method;

[0135] Sample specification settings:

[0136] Based on the structural characteristics of the irregularly shaped drainage pipe of this invention (including reinforcing plate 3 and connecting outer convex ring 2), the uniform specifications for the experimental samples are determined as follows:

[0137] Specifications numerical values illustrate Nominal inner diameter 300mm Conforms to the commonly used inner diameter range of municipal drainage pipes Minimum thickness of inner wall of pipe body 1 1.8mm Ensure the strength of the inner wall bearing foundation Minimum thickness of outer wall of pipe body 1 2.8mm Adapt to the connection strength requirements of reinforcement plate 3 Reinforced Plate 3 Structure arch Referring to claim 3, the arched structure has the best compressive strength. Reinforcing plate 3 dimensions Thickness 3mm, width 50mm Uniformly distributed along the axial direction of pipe body 1 Reinforcing plate 3 spacing 100mm Avoid excessive spacing that could lead to localized stress concentration. Connecting external convex ring 2 specifications Width 20mm, Height 5mm Matching pipe connection sealing requirements Sample length 300mm (ring stiffness / ring flexibility), 200±10mm (drop hammer impact) Meets the sample length requirements of various testing standards. Cutting position The ring stiffness / ring flexibility sample is cut between the reinforcing plates 3, and the drop hammer impact sample avoids the reinforcing plates 3. Eliminate the interference of reinforcing plate 3 on the test results

[0138] Test equipment and environment:

[0139] The experimental equipment and environmental conditions for this invention are specified as follows:

[0140] Test Project Equipment Model Test environment Implementation Standards Ring stiffness / ring flexibility CMT5105 Electronic Universal Testing Machine Temperature 23±2℃, relative humidity 45%-65% GB / T9647-2015 (Ring Stiffness), ISO13968-2008 (Ring Flexibility) Vicat softening temperature XWB-300F Vicat Measuring Instrument Temperature 23±2℃, vibration-free environment GB / T1633-2000 (A50 method) Drop hammer impact ZBC-40B Drop Weight Impact Testing Machine Pretreatment temperature -5±1℃, test temperature 23±2℃ GB / T14152-2001 Oven test DHG-9070A Electric Heating Constant Temperature Drying Oven Temperature 110±2℃ (suitable temperature for ABS material) Clause 8.7 of GB / T19472.1-2019 Oxidation-induced DSC-60 Differential Scanning Calorimeter Nitrogen atmosphere, heating rate 10℃ / min GB / T19466.6-200

[0141] Supplement to Test Methods

[0142] (1) Ring stiffness test:

[0143] Loading methods: There are two scenarios: loads are borne on the top and bottom surfaces (simulating vertical pressure of underground backfill soil) and loads are borne on the left and right horizontal surfaces (simulating lateral earth pressure).

[0144] Loading rate: 5 mm / min (refer to the comparison file to avoid stress sudden changes due to excessive speed);

[0145] Data recording: When the deformation of the outer diameter of pipe body 1 reaches 5%, 10%, 15%, 20%, and 25% of the original outer diameter, record the bearing capacity F (kN), peak stress (MPa), and reduction (mm) respectively, according to the formula: Calculate the load S (kN / m²), where S is the load, L is the sample length, D is the nominal inner diameter, and ΔD is the deformation.

[0146] (2) Ring compliance test:

[0147] Sample preparation: The sample length is 300 mm, and the cut surfaces at both ends are perpendicular to the axis of tube 1. Remove any burrs.

[0148] Loading requirements: The test force is continuously increased. When the deformation of the outer diameter of the tube body 1 in the vertical direction reaches 30% of the original outer diameter, the load is immediately unloaded. Observe whether cracking, separation of inner and outer walls, or reverse bending of the inner wall occurs.

[0149] (3) Drop hammer impact test:

[0150] Hammer head specifications: D90 type (hemispherical, 90mm in diameter);

[0151] Impact parameters: Drop hammer mass 3.2kg, impact height 2000mm (same as the comparison document to ensure consistent impact energy);

[0152] Pretreatment: The sample was placed in a refrigerator at -5±1℃ for 2 hours, and the shock was completed within 30 seconds after it was taken out;

[0153] Judgment criteria: The tube body 1 is considered qualified if there are no cracks or perforations after impact. Ten samples are tested in each group, and the pass rate is calculated (all embodiments of the present invention are 100% qualified).

[0154] (4) Oxidation-induced test:

[0155] Sample preparation: Take 3 samples from the inner and outer walls of tube 1 respectively, with a size of 10mm×10mm×2mm, and the surface is flat and free of impurities;

[0156] Experimental conditions: Initial temperature 50℃, temperature increased to 200℃ at 10℃ / min and kept constant, oxygen flow rate 50mL / min, record the time from the start of constant temperature to the appearance of the oxidation exothermic peak (i.e. oxidation induction time), and take the minimum value of each group as the result.

[0157] The test results are shown in Tables 1-3 below;

[0158] Table 1. Ring stiffness values ​​(loads borne by the upper and lower surfaces)

[0159] crystalline silicon powder Poisson's ratio Upper load (MPa) Bearing capacity F (kN) Load S (kN / m2) Example 20% 0.35 0.700 9.294 60.447 Example 1 20% 0.35 0.800 10.622 77.718 Example 2 20% 0.35 0.900 11.949 86.353 Example 3 20% 0.35 1.000 13.277 94.989 Example 4

[0160] Table 2. Ring stiffness values ​​(loads borne by the left and right horizontal planes)

[0161] crystalline silicon powder Poisson's ratio upper load Bearing capacity F (kN) Load S (kN / m2) Example 20% 0.35 0.467 6.196 40.298 Example 1 20% 0.35 0.533 7.081 51.812 Example 2 20% 0.35 0.600 7.966 57.569 Example 3 20% 0.35 0.669 8.851 63.326 Example 4

[0162] Table 3 Comparison of Results from Examples

[0163] Testing items Example 1 Example 2 Example 3 Example 4 Ring stiffness (kN / m2) 60 77 90 81 Ring flexibility No breakage or detachment No breakage or detachment No breakage or detachment No breakage or detachment Vicat softening temperature (°C) 112 129 143 152 Drop hammer impact (%) Non-destructive Non-destructive Non-destructive Non-destructive Oven test No layering, cracking, or bubbling No layering, cracking, or bubbling No layering, cracking, or bubbling No layering, cracking, or bubbling Oxidation induction (min) 42 45 55 49

[0164] Based on the comprehensive sample preparation, test data, load stress simulation, and performance analysis results, Example 3 is the best performing example. Its core advantages lie in its leading comprehensive performance indicators: ring stiffness reaches 90kN / m² (the highest among all examples, far exceeding the 41kN / m² level of high-strength pipes in the comparative documents); Vicat softening temperature is 143℃, meeting the requirements of underground high-temperature environments; oxidation induction time is 55min, demonstrating outstanding anti-aging ability; drop hammer impact test is qualified, exhibiting excellent impact resistance; and acid and alkali corrosion resistance is suitable for wastewater scenarios.

[0165] High ring stiffness ensures strong support and resists soil compression deformation: The ring stiffness of Example 3 reaches 90kN / m², which is much higher than the backfill soil pressure required for municipal deep buried drainage projects (burial depth ≥ 3m) (about 45kN / m²). When the pipeline is subjected to vertical compression of soil, the crystalline silicon powder is evenly dispersed in the ABS matrix to form "rigid support points". Combined with the arched reinforcing plate 3 structure, the vertical compression force can be converted into axial force, avoiding radial stress concentration.

[0166] In summary, the non-cylindrical drainage pipe of this invention specifically addresses the problems of weak compressive strength, stress concentration, and poor adaptability of existing municipal cylindrical drainage pipes. It employs a combination design of a specific ratio of composite materials and an arched reinforcing plate 3, resulting in a ring stiffness far exceeding that of traditional cylindrical pipes. This allows it to easily withstand the pressure of backfill soil buried deep underground, ensuring a high safety factor. The non-cylindrical structure of the pipe body 1, combined with the reinforcing plate 3, converts some of the vertical compressive force into axial force, dispersing stress evenly through a specific path. This avoids the stress concentration problem at the top of traditional cylindrical pipes, and the stress peak under compression is far lower than the material's yield strength. Simultaneously, the synergistic effect of specific components enhances the pipe's resistance to acid and alkali corrosion and its self-lubricating properties, reduces soil friction and wear, exhibits excellent anti-aging properties and structural stability, and has a low long-term attenuation rate of support force. This avoids the drawbacks of traditional concrete pipes, such as high weight and poor crack resistance, while also addressing the insufficient stiffness of ordinary plastic pipes. It meets the long-term high-strength and high-durability requirements of municipal drainage pipes, reducing maintenance costs and the risk of flooding.

[0167] Although embodiments of the invention have been shown and described, the scope of the invention will be defined by the appended claims and their equivalents by those skilled in the art.

Claims

1. An irregularly shaped pipe, characterized in that, The tube (1) includes a tube body (1), which is externally fixedly connected to multiple sets of reinforcing plates (3). One end of the tube body (1) is fixedly connected to a connecting external protruding ring (2). The shape of the tube body (1) is an irregular shape or a regular polygonal structure.

2. The irregularly shaped pipe according to claim 1, characterized in that, The inner cavity of the tube (1) is circular, elliptical or polygonal, and the tube (1) is teardrop-shaped or spindle-shaped.

3. The irregularly shaped pipe according to claim 1, characterized in that, The tube body (1) is composed of the following raw materials in parts by weight: Organic materials: 65–95 parts; PTFE; 1-5 parts; Crystalline silicon powder: 5-35 parts; 1-5 parts of silane coupling agent; Antioxidant DSTDP: 1-5 parts; UV absorber uv531: 1-5 parts; Paraffin wax: 0.5–2 parts; Stearic acid: 0.5–2 parts; Color masterbatch: 1 to 5 parts.

4. A method for preparing an irregularly shaped pipe, characterized in that, Specifically, the following steps are included: Step 1: Weigh the raw materials according to the specified weight proportions, mix and stir them evenly, and set aside. Step two: Heating is performed by heating the head and main body sections of the screw extruder to the set temperature until a constant temperature is reached and maintained within ±5℃. Step 3: Start the screw extruder and feed at a low speed of 5-10 rpm. After running for 5-10 minutes without any abnormalities, gradually increase the speed to 75%-90% of the normal speed. After holding for another 5-10 minutes without any abnormalities, increase the speed to the normal speed and maintain normal feeding. Step 4, pipe shaping and cooling: After the pipe blank is extruded through the die head, it enters the cavity composed of the water jacket and the module. The negative pressure vacuum on the module shapes and cools it. The forming machine rotates continuously, pulling the shaped pipe out onto the pipe support. Step 5: Pipe cutting and transportation. Cut the cooled and shaped pipes according to the length requirements. The cutting surface should be perpendicular to the pipe axis. Cut neatly and remove any burrs. Step six: The cut and trimmed pipes are neatly stacked on the transport vehicle and transported to the storage yard.

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