PE mining pipe is a kind of PE pipe. PE pipe for mining has the advantages of light weight, long service life and convenient construction. Its weight is only 1 / 7 of that of steel pipe and 1 / 2 of that of FRP pipe, and the service life is 4-5 times that of steel pipe. It is convenient for transportation and installation, especially underground, which can greatly reduce the labor intensity of workers and improve work efficiency. It has strong corrosion resistance, does not need anti-corrosion treatment, saves relevant expenses, and its comprehensive benefit is 5-7 times that of steel pipe. It is especially suitable for underground transportation of high sulfur water.
Industry Standard Requirements of PE Mining Pipe
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Appearance: The inner and outer walls of PE mining pipe shall be smooth and flat without bubbles, cracks, obvious grooves and depressions, and the appearance color shall be uniform. Both ends of each pipe shall be perpendicular to the axis.
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Wall Thickness Deviation: The wall thickness deviation of the same section of the pipe shall not exceed 14%.
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Wall Thickness: The minimum wall thickness of the pipe corresponding to the nominal outer diameter and nominal pressure shall meet the standard requirements.
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Out of Roundness: The out of roundness of pipes shall not be greater than 5%.
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Flat: PE mining pipe is pressed to the inner wall, and there shall be no crack and damage.
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Hydraulic Pressure: PE pipes shall be free from leakage and damage when the test pressure is maintained for 100h.
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Tensile Strength and Elongation at Break: the tensile strength shall not be less than 9.0MPa, and the elongation at break shall not be less than 300%.
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Surface Resistance: According to different uses of PE mining pipe, its surface resistance requirements are also different.
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- Water supply and drainage pipes: the arithmetic mean value of surface resistance of outer wall shall not be greater than 1.0 × 109Ω；
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- Positive pressure air duct: the arithmetic mean value of surface resistance of inner and outer walls shall not be greater than 1.0 × 108Ω;
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- Pipe for shotcreting: the arithmetic mean value of surface resistance of inner and outer walls shall not be greater than 1.0 × 108Ω;
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- Negative pressure air duct: the arithmetic mean value of surface resistance of inner and outer walls shall not be greater than 1.0 × 106Ω;
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- Gas drainage pipe: the arithmetic mean value of surface resistance of inner and outer walls shall not be greater than 1.0 × 106Ω。
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The flange for coal mine shall be greater than or equal to various technical standards of PE mining pipe.
Design Requirements for PE Mining Pipe
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Due to the rigidity and linear expansion coefficient of its material, when considering the strength problem, the number of fixed points must be increased to ensure the rigidity of the water supply network; When considering the linear expansion coefficient, it must be considered that there must be a certain amount of expansion for the laying of long-distance pipelines.
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The buried depth of the pipeline shall be determined according to the freezing degree, the crossing of external load with other pipelines and other factors. In general, the burial depth can be 0.2m below the freezing line, and the minimum burial depth of the pipe top is 1.0m when the pipe diameter is greater than 110mm.
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The bottom of the trench is generally the outer diameter of the pipe plus 0.4m, the edge of the pipe trench shall be a straight line, the trench bottom shall be in a plane, and the trench shall not contain protrusions, gravel or other hard blocks. When mechanical trenching is used, 0.2 ~ 0.3m thick soil layer shall be reserved at the bottom of the ditch for temporary excavation. Finally, the bottom of the ditch shall be cleaned manually to the elevation.
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During pipe laying, 20cm medium coarse sand shall be backfilled at the top of the pipe, and 15cm sand cushion shall be made at the bottom of the pipe.
Pressure Test of PE Mining Pipe
The pressure test of PE mining pipe is carried out in two stages: pre-test stage and main test stage.
Pre-test Stage
In the pre-test stage, the steps are as follows:
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Reduce the pressure in the pressure test PE mining pipeline to atmospheric pressure for 60 minutes. Ensure that no air enters the pipe during this period.
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Slowly pressurize the mining PE pipeline to the test pressure and stabilize it for 30 minutes. If the pressure drops during this period, water can be injected to supplement the pressure (but not higher than the test pressure). Check whether there is leakage at pipe interfaces and fittings (if any, stop the pressure test, find out the causes and take corresponding measures before organizing the pressure test).
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Stop water injection and pressure supplement and stabilize for 60 minutes. If the pressure drops below 70% of the test pressure after 60 minutes, stop the pressure test, find out the cause and take corresponding measures before organizing the pressure test.
Main Test Stage
In the main test stage, the steps are as follows:
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After the pre-test stage, the pipeline shall be released and depressurized quickly, and the depressurization amount shall be 10-15% of the test pressure.
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Record the residual pressure of PE mining pipeline every 3 minutes for 30 minutes. If the residual pressure of the pressure test pipeline has an upward trend within 30 minutes, the hydrostatic test result is qualified.
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If the residual water pressure in PE mining pipeline does not rise within the above 30 minutes, continue to observe for another 60 minutes. If the pressure drop does not exceed 0.02MPa within the whole 90 minutes, the hydrostatic test result is qualified.
Madisonpipe is an professional PE pipe manufacture, the performance of our raw materials is as: high performance superconducting carbon black is used as antistatic agent, decabromodiphenyl ether and antimony trioxide are used as flame retardant, which are fully mixed, plasticized and granulated. The physical and mechanical properties of the gas pipe produced with this special material can meet the pe-80 water supply pipe standard, and the antistatic and flame retardant properties can meet the standard requirements of mt558.1-2005 of the Ministry of coal.