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• Release time：2025-09-02 08:00
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【概要描述】The Importance of Post-Weld Straighteners in Second-Hand Welded Pipe Machines​ Post-weld straighteners are critical finishing components in second-hand welded pipe machines, responsible for correcting pipe bending and ensuring dimensional straightness after the welding process. Their performance directly impacts the usability of welded pipes in downstream applications and reduces post-production rework.​ Straightness Accuracy Assurance​ In second-hand welded pipe machines, post-weld straighteners use multi-roll (typically 7-11 rolls) configurations to apply controlled pressure on bent pipes. High-precision straighteners achieve a straightness tolerance of ≤1mm per meter for pipes with diameters ranging from 20mm to 500mm, meeting industry standards such as GB/T 3091-2020 for low-pressure fluid 输送 pipes. For example, a 6-meter-long DN100 welded pipe processed by a well-calibrated straightener will have a maximum bending deviation of ≤6mm, eliminating the need for manual straightening. In contrast, outdated or misadjusted straighteners can result in straightness deviations of 3-5mm per meter, leading to pipe rejection rates as high as 15%.​ Pipe Surface Protection​ Modern post-weld straighteners in refurbished second-hand welded pipe machines feature roll surfaces coated with polyurethane (PU) or nylon. These materials prevent surface scratches and indentations on the pipe, which is crucial for pipes used in decorative or corrosion-resistant applications (e.g., stainless steel welded pipes for architectural handrails). The coating hardness (Shore A 85-90) balances wear resistance and surface protection, extending roll life by 2-3 times compared to uncoated steel rolls. For second-hand machines with worn roll coatings, replacing the coating can reduce surface defect rates by 40-50%.​ Production Efficiency Enhancement​ Post-weld straighteners with automatic pipe diameter adjustment in second-hand welded pipe machines reduce setup time between pipe size changes by 50-60%. Traditional manual adjustment requires 20-30 minutes to reposition rolls for a new pipe diameter, while automatic systems (equipped with servo motors and position sensors) complete the process in 5-8 minutes. This is particularly beneficial for small-batch, multi-specification production, increasing the machine’s overall throughput by 15-20%. Additionally, straighteners with integrated speed synchronization (matching the pipe conveying speed of 15-30m/min) avoid pipe jams, minimizing unplanned downtime.​ Maintenance Guidelines​ To maintain the performance of post-weld straighteners in second-hand welded pipe machines:​ Inspect roll surface condition weekly; replace rolls if coating wear exceeds 0.5mm or if cracks/peeling occur.​ Check roll alignment monthly using a laser straightness meter; adjust roll positions if alignment deviation exceeds 0.1mm.​ Lubricate the straightener’s drive gears and bearing seats monthly with industrial gear oil (ISO VG 150) to reduce friction.​ Calibrate the pressure control system quarterly to ensure consistent roll pressure (typically 0.3-0.8 MPa, depending on pipe thickness).​ Upgrading the control system of older post-weld straighteners to a PLC-based automatic adjustment system can further improve straightness accuracy and reduce operator intervention, with a typical payback period of 9-12 months.​ For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier：www.usedpipemill.com​