【Ten Years of Rapid Development in Chemical Processing Equipment】2796-2025: Construction Management of Ethylene Process Piping Projects at Huanqiu Liu Jian’s Tarim Project Site – Completion of All Tasks

A way out of the crisis – why declare war on the ‘end items’ of process pipelines? The Tarim ethylene plant is the cornerstone of the project, and Liu Jian Company is responsible for the construction of all aspects except for the civil engineering foundations and floors. The project faces challenges such as high complexity, tight deadlines, strict quality requirements, and difficulties in coordination due to its remote location. These factors force the management team to seek more efficient management approaches. Process pipelines serve as the \"arteries\" that connect the entire production system; they are made from various materials including carbon steel, alloy steel, and stainless steel. The welding processes involved are complex, and the quality requirements are extremely high. There are also many risks, such as intricate cross-tasking, frequent work at heights, and significant safety hazards during construction. The amount of welding work required is as much as 1.28 million inches. Given that process pipelines represent a tough challenge to handle, the quality and progress of their construction directly determine the success or failure of the project. Achieving completion of all tasks without any outstanding items can greatly improve the level of precision in project management, ensuring that the project is completed efficiently and to a high standard. This places higher demands on us: throughout the entire process from construction preparation to completion and delivery, through advance planning and ongoing oversight, we must eliminate the traditional approach of completing the main work first and dealing with the details related to support pipes later. Instead, we need to achieve a construction management style in which all tasks such as pipe installation, pressure testing, and purging are completed in one go, so that there are no remaining quality issues or unfinished tasks at the time of completion.

Core revelation – The “Tarim Practice” concept for construction without tail items takes the lead, ensuring proactive preparation. At the Tarim project site, the trial implementation of tailless construction management was first a profound ideological transformation. It fundamentally challenges the conventional thinking in project management, shifting the focus of quality management from end-stage \"inspection and correction\" to the initial stage of \"planning and prevention\". Tang Guiquan, the project deputy manager at Zhongke Company, pointed out incisively at the seminar on construction without leftover tasks: \"Having no leftover tasks requires first and foremost a determination to get it right from the start, rather than resorting to remedies after the fact.\" ”This concept completely reverses the old notion of \"prioritizing progress and dealing with remaining tasks later.\" In the past, project teams often acted like a \"fire brigade\"; after the main construction was completed, they had to deal with a lengthy \"post-project cleanup period,\" spending numerous resources to fix the problems that had arisen earlier. And the tailless thinking approach requires every participant – from management to frontline welders – to become both “planners” and “preventers”. It no longer pursues mere “completion,” but rather the ideal state of “completion equals completion.” This shift essentially views quality as an inherent attribute that must be built into the process, rather than a label that can only be obtained through post-event inspection. It requires that all work have its starting points planned based on a clear goal, ensuring that each step is carried out with precision so as to embed the principle of \"excellence from the start\" into the \"steel framework\" of the project. During the installation of the steel structure in the pyrolysis gas compressor plant, a management concept featuring no residual work was introduced first. Due to the high height of the pyrolysis gas compressor building and the large number of components involved, specific plans and requirements were established early in the installation process, covering aspects such as the construction plan and the material delivery needs. During the installation of the roof beams, the prefabricated units were divided into left and right sections; all components, along with the bolts, were fully tightened and welded, and repainting was carried out. This ensured that the installation was completed as soon as the components were hoisted into place, providing a solid foundation for the subsequent sealing of the building’s exterior panels and the installation of the compressors.

Laying a technical foundation while strictly adhering to the \"quality bottom line\". All drawing reviews and technical briefings must be completed prior to the construction of process pipelines. Pipeline materials (pipes, valves, fittings) must be verified 100% to prevent incorrect or mixed use; key parameters such as pipeline material and welding process grade must be clearly defined to avoid rework due to design changes or ambiguities in the drawings. Before construction, a thorough technical breakdown of all procedures must be carried out to clarify the quality standards, process parameters, and inspection points for each stage, thereby preventing the situation where work is done only to have to make corrections later. The Tarim project adheres to the principle of \"complete processes, complete quality\" – each process (such as pipeline prefabrication, on-site installation, and self-inspection) must be approved before moving on to the next one, thereby preventing quality defects from previous processes from accumulating and turning into \"remaining issues\". Building on the 4D pipeline welding management system used in the Tarim Phase II project, this initiative involves attaching a QR code next to each weld seam, thereby creating an “ID” for each of those welds. This approach opens up new ways for pipeline installation, ensuring comprehensive management of pipelines throughout their entire lifecycle from installation to operation. The “history” of each pipeline can be tracked and documented. By scanning the QR code using a mobile app, all information related to that weld seam is readily available.

Process control to strengthen the “quality defense line”. During the preliminary planning and control phase, the construction tasks are broken down to each weld joint and each inspection point; the responsible persons for various tasks along with the corresponding time deadlines are identified. Special attention is paid to the quality control requirements for key areas such as high-pressure pipelines and low-temperature pipelines, and relevant technical instructions are provided in advance. During the construction phase, the \"three-inspection system\" is strictly implemented: after each task is completed, the workers first conduct self-inspections, followed by mutual inspections among different teams, and then specialized inspections are carried out by dedicated quality control officers to ensure that the quality of each task meets the standards. Only after passing all the self-inspections, mutual inspections, and specialized inspections will we take the initiative to contact the project’s dedicated staff, supervisors, and the client to assist in carrying out the joint inspections by all three parties. Only after signing off and obtaining explicit approval will we proceed to the next construction step (such as water pressure testing), firmly avoiding any work being carried out before inspections are completed ； Timely organize construction data (such as welding records and inspection reports) to enable dynamic early warning of residual risks. During the issue rectification phase, a \"list of remaining hazards\" is established to keep track of the identified problems (such as failed welding defect inspections or unresolved issues resulting from No delivered materials); these issues are managed using a \"closure system\". After rectification, re-inspection and acceptance are required to ensure that 100% of the hazards have been eliminated. During the completion inspection phase, a \"pre-acceptance without outstanding items\" is carried out in advance; each item is checked against the design drawings and regulatory requirements to ensure that no tasks are left unaddressed, before the completion documents are officially submitted. There are a total of 1,268 pressure testing packages in the ethylene plant. During the pipeline completion phase, the project utilized these pressure testing packages to facilitate the completion of the pipeline work. By improving the quality of the documentation related to these pressure testing packages, by assessing in advance the progress of the tasks involved in each package, and by assigning dedicated personnel to oversee the completion of these tasks, a hierarchical quality control system was established, ranging from team leaders and shift supervisors to quality inspection staff. This ensured that quality control was handled at every stage of the process, with someone responsible for checking and signing off on each step. To date, pressure testing has been completed successfully for 228 of these packages.

Demonstrated value – the undeniable fact that the benefits outweigh the drawbacks. Although endless construction requires more manpower and time in the initial stages for technical planning and process control, its key advantages more than compensate for these costs, eliminating the waste of effort associated with moving tools back and forth. If another team is assigned to complete the work, technical briefings and drawing reviews will have to be carried out again, resulting in extremely low efficiency. Quality and efficiency. To completely eliminate issues such as secondary welding of pipes and repeated pressure testing that arise from \"final adjustments\" in traditional construction methods, on October 14, 2025, project quality inspector Wei Yanwei discovered during a specialized spectral inspection of the pipelines attached to Reactor No. 5, whose material was P11, that the welding material used for the pipe support welds was incorrect. Upon verification, the material of the pipe support arc plate is 15CrMo, while the material of the main pipe is A335 P11. By comparing the welding procedure specifications with the spectral data, it was determined that the issue was caused by an incorrect selection of welding materials. Through effective quality control measures, quality problems were identified and corrected in advance, ensuring that the pressure testing procedures were carried out thoroughly and meticulously. This approach guarantees the long-term safe and stable operation of the ethylene process pipelines, thereby reducing the risk of production shutdowns due to quality issues in the future. Material benefits. Accurately count the types and quantities of missing materials to ensure the integrity of the pressure testing package. The information on missing materials is updated in real time, facilitating timely procurement and allocation. The project has established a master table for controlling the receipt and distribution of materials. Through measures such as managing the total amount of materials per area and team, as well as implementing limits on receipt and distribution, during the pipeline pressure testing phase, teams can promptly report lists of material shortages via work groups. Designated personnel then check where the materials have gone, and any issues such as over-receipt or incorrect receipt are addressed promptly. The causes of these shortages are analyzed based on the type of material issue, thereby continuously improving the material management process. To date, 131 cases of over-receipt or incorrect receipt of materials have been identified, of which 108 have been resolved.