Innovation-driven, Smart Manufacturing for the Future

Against the backdrop of the national 14th Five-Year Plan's vigorous promotion of clean and efficient utilization of coal, Xinjiang Sanchang Environmental Protection Energy Co., Ltd.'s 400,000-ton/year coal tar resource utilization project, located in the Hu Yanghe Economic and Technological Development Zone of the Seventh Division of the Xinjiang Production and Construction Corps, has become a benchmark for the circular economy industry chain. As the core equipment supplier for this project, Dalian Dongfang Yipeng Equipment Manufacturing Co., Ltd.'s "pre-reaction product/pre-reaction feed heat exchanger (230-E-201A/B)" final equipment was successfully delivered in mid-March 2025. Its ultra-large specifications, high-difficulty manufacturing process, and cutting-edge material applications mark another breakthrough in Dongfang Yipeng's high-end pressure vessel manufacturing capabilities.

I. Equipment Features: The Dual Challenge of Ultra-Large Diameter and Composite Materials  

The specifications of this heat exchanger are DFU1700-12.0/12.54-1053-7.35/25-2I ，it is currently the largest diameter (Φ 1700mm ) threaded locking ring heat exchanger in China. Its core features are:

1. Material Characteristics: The main body uses 14Cr1Mo Grade Ⅳ high-strength chromium molybdenum steel, with inner wall cladding of TP309L+TP347 austenitic stainless steel, combining high-temperature creep resistance, high-temperature hydrogen corrosion resistance, and resistance to sulfide stress corrosion cracking, suitable for the extreme operating conditions of coal tar hydrogenation units.

2. Complex Structure: The processing and design of the new large-diameter threaded locking ring wide-tooth thread must ensure sealing under high pressure ( 12.54MPa ) while enabling rapid sealing of the tube bundle without shutdown, improving maintenance efficiency by 50% or more compared to traditional heat exchangers.   

II. Production and Manufacturing Difficulty: A Comprehensive Breakthrough in Technological Barriers

1. Material Welding Challenges: 14Cr1Mo Grade Ⅳ cladding with TP309L+TP347, requires strict control of heat input to avoid coarse grains in the base metal heat-affected zone, deterioration of mechanical properties, and defects such as reheating cracks. In addition, the selection of cladding welding materials for corrosion resistance must strictly control Cr/Ni value and carbon content to ensure that the ferrite in the cladding layer is controlled within 3-8 %, meeting the product performance requirements for intergranular corrosion resistance.

2. Ultra-large Component Machining: The diameter of the 2.3 meter tube box cylinder body large-diameter wide-tooth inner thread machining, and the diameter of the 2 meter threaded locking ring large-diameter wide-tooth outer thread machining tolerance must be controlled within ± 0.02mm ，posing an extreme challenge to machine tools and operating skills.

3. Heat Treatment and Inspection: The equipment must undergo multiple post-weld heat treatments ( PWHT ), and pass 100% radiographic testing ( RT ) and time-of-flight diffraction ultrasonic testing ( TOFD ) to ensure that there are no defects.

III. Process Requirements: A Model of Digitalization and Lean Manufacturing

Dalian Dongfang Yipeng adopts the "digital twin + modular manufacturing" model:

- Through 3D modeling simulation assembly stress, optimize the pre-tightening force distribution of the threaded locking ring;

- Introduce narrow-gap automatic welding technology to reduce welding deformation;

- Strictly implement ASME and GB/T 150 standards, the fully traceable quality control system is recognized by customers.

IV. Industry Status: A Milestone for High-end Domestic Equipment

The successful manufacturing of this large-diameter threaded locking ring heat exchanger has broken the long-term monopoly of several companies in the domestic market for similar equipment. Its technical parameters, such as design pressure, temperature, diameter, and non-destructive testing of pressure vessels, have surpassed most similar products, becoming a benchmark for domestic substitution in the coal chemical and petrochemical industries.

V. Empowering Green Transformation with "Hardcore" Equipment

Dalian Dongfang Yipeng's breakthrough not only reflects the upgrade of China's national equipment manufacturing industry from "follower to leader," but also responds to the national "dual carbon" goals and the demand for clean energy technologies. As Xinjiang Sanchang Environmental Protection Energy Co., Ltd.'s 40 ten thousand tons / annual coal tar resource utilization major project, located in the Seventh Division of the Xinjiang Production and Construction Corps, Hu Yanghe Economic and Technological Development Zone, it follows the industrial route of clean and efficient coal utilization vigorously promoted by the national "14th Five-Year Plan," actively deploying the "coal - electricity - oil - gas" circular economy industry chain. Through selective hydrorefining and extractive distillation processes, using waste mineral oil, distillation residue, and bottom oil as raw materials, it processes and produces high-standard aromatic products, greatly increasing the added value of products and achieving resource comprehensive utilization, turning waste into treasure. Dongfang Yipeng's high-end large-diameter threaded locking ring heat exchanger is the "heart component" of this circular economy chain.

Practicing the "dual circulation" development strategy and contributing Eastern wisdom

Dongfang Yipeng's high-end petrochemical equipment has been exported overseas. In the future, with the high-end development of coal chemical and hydrogen energy industries, domestic equipment enterprises need to continue to focus on the deep integration of materials science and intelligent manufacturing. Dalian Dongfang Yipeng's practice proves that only by overcoming "bottleneck" problems through innovation can we promote the transition of "Made in China" to "Created in China".

The world is undergoing a once-in-a-century transformation, and with increasingly complex and severe external environments such as high tariffs and trade barriers, Dongfang Yipeng actively implements the national "dual circulation" development strategy. By promoting stability through opening up and upholding the right principles while innovating, we seek opportunities amidst change, integrating our development into the national development strategy. We advocate for an equal and orderly multipolar world and the construction of an inclusive and beneficial globalized economy. We continuously inject strong new impetus into accelerating the development of the western region and promoting the "Belt and Road" initiative's new model of human civilization, contributing Dongfang wisdom and strength to the development of China's national equipment manufacturing industry and its global presence.