Common problems with plastic pipes

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Common problems with plastic pipes can be classified into three categories: faults during the production process, issues that arise during use, and misunderstandings in the selection process. The details are as follows: 1. Common faults during the production process (abnormalities in production line equipment) These occur mainly during the extrusion molding of plastic pipes. Typical problems and solutions include: dimensional/wall thickness deviations – such as excessive outer diameter or uneven wall thickness – which can be addressed by adjusting the vacuum level and pulling speed, modifying the mold wall thickness, and checking the tightness of the mold screws. Abnormal surface quality: grooves on the outer surface, roughness/dents on the inner wall, and a lack of luster in the tube wall. These issues are often related to poor plasticization, blocked water channels, or defects in the mold materials; it is necessary to adjust the process temperature, clean the mold and water channels, and optimize the amount of lubricant used. Roundness deviation: Elliptical deformation of the tubing, primarily caused by uneven cooling; it is necessary to adjust the angle of the nozzles in the spray box and check the water temperature; a chilled water system should be installed if the temperature exceeds 35°C. Abnormalities in the co-extruded identification strip: issues such as spreading, absence of the strip, or uneven thickness occur, usually due to improper selection of the co-extrusion material or a mismatch between the extrusion volume and the pulling speed. It is necessary to use a suitable co-extrusion material or adjust the frequency of the inverter or the pulling speed. Vacuum/length measurement fault: In the event of a vacuum failure, it is necessary to clear the water inlet of the vacuum pump and check its sealing ； The length measurement error of the cutting machine requires checking the gauge wheel pressure, limit switches, and encoder grounding. II. Common problems during use: After the piping is put into use, four typical types of problems can occur: leakage due to weak connections – Plastic joints are prone to loosening and leaking, usually as a result of poor quality of the connecting fittings or improper installation. Rupture/cracking: This is often caused by insufficient temperature resistance and inadequate pressure-bearing capacity of the material; external forces or fluctuations in water pressure can easily lead to damage. Chemical corrosion damage: Some plastic materials have poor chemical resistance and are prone to corrosion when in contact with certain substances, which affects their safety of use. Ageing and deformation: Due to long-term use and environmental influences, ageing and deformation occur, reducing the structural stability of the pipes. If it is a PVC drainage pipe, there are additional specific problems such as poor heat resistance, sensitivity to ultraviolet light, and easy aging. III. Common mistakes in the purchasing process: Ordinary consumers tend to make these errors when making purchases: judging quality based on color, assuming that white is necessarily better than gray or black; in fact, color is not the key criterion for determining the quality of pipes. By ignoring the wall thickness and using substandard materials, thin pipes have poor thermal insulation and compressive strength, as well as a shorter service life. Without verifying the purity of raw materials, recycled materials or pipes contaminated with impurities may have an unpleasant odor and be prone to breaking, thereby compromising water safety.