【History of Haichuan Pipelines】20151014 Jiyuan to Luoyang 25-kilometer hydrogen pipeline project in Luoyang Refining and Chemical Industry

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Sinopec Luoyang Refining & Chemicals’ Hydrogen Pipeline Project from Jiyuan to Luoyang – 10/14/2015. Source: China Petroleum News. Wangwushan in Jiyuan City, Henan Province, is the birthplace of the story of \"Yu Gong moving the mountains\". In 2015, the builders of Pipeline Company No. 3 came here and, facing Mount Wangwu, once again brought to life the story of \"The Foolish Old Man Who Removed the Mountains\". The Jiyuan to Luoyang hydrogen pipeline project, constructed by Pipeline Company No. 3 for Sinopec Luoyang Refining & Chemical, has a horizontal length of 25 kilometers, with an annual gas transport capacity of 100,400 tons. The terrain along the pipeline is mainly hilly, with significant elevation variations. Along the pipeline, roof box culverts cross railways in 2 locations, pipe jacking methods are used to cross a provincial highway in 1 location and 5 other roads, while directional drilling is employed to cross gullies in 2 instances and rivers in 1 instance. The successful completion of this project not only filled a gap in the pipeline industry but also played a crucial role in helping the pipeline company transform from a general contractor to a comprehensive service provider. Plan ahead carefully: the medium transported through the hydrogen pipeline is hydrogen. Hydrogen is among the first group of hazardous chemicals that are subject to strict regulation. It is highly prone to leakage and dispersion, has a low ignition energy, a wide explosion range, and high chemical reactivity, which imposes very high requirements on pipeline welding. The Pipeline Bureau was extremely cautious in selecting the units, and the CPP313 unit, which has received the honor of \"National Quality Trustworthy Team,\" took on this important task. The CPP313 unit performs excellently in automatic welding, but the application of automatic welding is limited by the terrain; it is difficult to use it in mountainous or steep areas. One month before starting operations, this welding unit carried out thorough preparations in terms of personnel, equipment, and materials: it assembled a team of highly skilled workers for specialized training, with focus given to two welding methods – tungsten inert gas welding and low-hydrogen electrodes – in order to ensure the highest quality of welds ； Through one-on-one guidance and demonstration, as well as continuous experimentation and adjustment, the employees have made significant improvements in their skills regarding the adjustment of welding power supplies, the welding properties of electrodes, welding angles, and the techniques of manual welding. Overcoming technical challenges skillfully: On March 29, the project officially commenced welding work. Despite thorough preparation, \"problems\" arose; pores appeared in a few weld passes. To this end, the team’s technical experts gathered to inspect the site and investigate the cause. By controlling the wall thickness, continuously adjusting the current parameters, and exploring the appropriate welding angle and wire movement speed, the technicians learned to understand the characteristics of this hydrogen pipeline. “Each welder has records for each weld joint. ”Technician Hao Songliang said that no matter what the problem is, it is possible to identify the corresponding \"owner\" accurately, thereby preventing similar issues from recurring. The team also carried out quality risk identification at various stages such as trench excavation, pipe laying, alignment, and welding. Based on the identified quality risks, effective control measures were established, with responsibilities assigned to specific individuals, which laid a solid foundation for a first-weld qualification rate of up to 99% for the unit. This pipeline has to pass through steep cliffs and slopes. Although its length is not great, the area it traverses is full of ravines and steep cliffs, which poses many difficulties for construction. The depth of the vertical shaft on the north side of the Changji Expressway crossing reaches 26 meters; two 90-degree elbows and two straight pipes are required in this shaft to complete the construction. The unit adopts a construction method in which two elbows and straight pipes are prefabricated as a whole before being lifted and assembled. The opening at the top of the shaft is narrow, making it very difficult to carry out lifting operations while ensuring both precision in lifting and the integrity of the anti-corrosion coating on the prefabricated pipe sections. The project team and the crew used two excavators along with a 25-ton crane to carry out the work; during lifting, chain blocks were used continuously to precisely adjust the position and angle of the prefabricated pipe sections. This small innovation enables prefabricated pipe sections to enter the shaft safely and smoothly. On September 7, the Jiyuan-Luoyang hydrogen pipeline project was put into operation successfully. The CPP313 unit continued to surpass itself; at a time when efforts were being made to restore a positive image for China’s petroleum industry, it contributed to enhancing the reputation of the pipeline management agency through its practical actions in the hometown of Yu Gong.