First in the country! Terahertz detection equipment for petrochemical polyethylene pipelines successfully applied

The Institute of Engineering Materials recently successfully applied its independently developed first domestic set of terahertz online automatic detection equipment for polyethylene pipelines used in petrochemicals, shining brightly at the site of hot melt welding and laying of gas pipelines. This achievement marks a significant breakthrough by China National Petroleum Corporation in the field of non-metallic pipeline inspection technology, with its technical strength leaping to a leading position domestically.

At the inspection site, the automatic equipment conducted a detailed 3D scan imaging of the thermally fused joint of the DN250 polyethylene pipe that had been welded, clearly displaying the overall defect condition in real time. This technology provides a professional, scientific, and reliable non-destructive testing method for on-site welding quality control, greatly enhancing the safety and efficiency of pipeline construction.

Polyethylene pipe, as a common non-metallic pipe material, has been widely used in various fields such as oil and gas field surface gathering and transportation, urban gas, and refining, due to its excellent properties of corrosion resistance, wear resistance, and light weight. However, for a long time, the research and application of non-destructive testing technology for polyethylene pipelines globally have been relatively lagging, making it difficult to accurately and effectively detect and evaluate defects in the base material and welds, thus leading to multiple safety accidents.

According to the information, regarding the industry challenge of non-metallic pipeline non-destructive testing, since 2020, the oil pipe and equipment integrity research team of the Engineering Materials Research Institute, with strong support from national, group, and provincial key R&D projects, has faced the difficulties head-on. They have successively overcome a series of technical challenges including time-domain spectrum optimization for on-site terahertz detection of non-metallic pipelines, defect feature recognition, high-precision defect size calculation, and three-dimensional reconstruction. Ultimately, they successfully developed the first domestic set of online automatic terahertz detection equipment for polyethylene pipelines used in petrochemicals.

"Terahertz detection method has significant advantages such as high resolution, tomographic scanning, and 3D reconstruction," introduced Ma Weifeng, the director of the Oil Pipe and Equipment Integrity Research Institute at the Engineering Materials Academy. This new equipment can efficiently detect defects like inclusions and pores in the thermal fusion welding joints of polyethylene pipes, with a detection rate of over 95%, and the dimensional inspection error is controlled within 50 microns. It plays a crucial role in ensuring the quality control of polyethylene pipe thermal fusion joints and their service safety."