On December 4, the 2021 organized domestic experts to evaluate the DN5800 × 45mm integrally formed hydraulic expansion joint developed by Shandong Hengtong Expansion Joint Manufacturing Co. , Ltd. . Participating in the appraisal meeting are: The chief expert of Sinopec Engineering Construction Company, Professor Duan Rui, and the chief engineer of China Global Engineering Co. , Ltd. , Professor Jiang Xiaowen, professor Cao Qingjun, deputy chief engineer of Wanhua Chemical Group Co. , Ltd. , Professor Lu Zhiming, Professor Jiang Wenchun, China University of Petroleum, chief engineer of Duan Ruijun, Zhejiang University of Technology, guo Huaili, secretary general of Shandong Special Equipment Association, and Wu Jun, director of Tai'an Special Equipment Inspection Institute, are well-known experts, professors and user representatives in China.

    The expansion joint is used in a reactor in the indian-made 300,000 TPA VAM unit of the domestic Lianyungang fine chemical project. According to ASME VIII-1 APPENDIX 5, the original design of expansion joint was designed as semi-wave welded expansion joint, which needed to be formed by mechanical stamping. The Middle Circumferential weld joint was connected as a whole. The forming stress of this structure was large, and there were many welds, it will lead to the appearance of t-shaped welded joint and increase the risk of later use. Shandong Hengtong Expansion Joint Manufacturing Co. , Ltd. based on the past design, manufacturing experience, re-reference GB/T16749-2018“Pressure vessel corrugated expansion joint”for the design, change to the overall hydraulic forming structure, the design result is verified and approved by the equipment designer. The prototype is unprecedented in terms of diameter, thickness and forming pressure, making it extremely difficult to make. The company up and down the team, one-time development success, by the Indian Tata Company in Shanghai Branch test qualified.

    DN5800 × 45mm large diameter thick wall expansion joint is formed by hydraulic pressure, compared with traditional stamping forming process, circumferential weld and t-joint are avoided, Longitudinal Weld is reduced, and safety performance of expansion joint is improved. For the first time, the structure of multi-cavity ring sleeve is adopted, and the technology of forming large thick-wall expansion joint by low-tonnage press is realized. The multi-layer, multi-channel and soft-body cavity combined seal structure is proposed to solve the problem of integral hydraulic seal of large diameter expansion joint. 

    Experts agree that the successful manufacture of this product is an important achievement in the fields of petroleum, chemical industry, metallurgy, electric power, water conservancy, aerospace, aviation and other fields in China, and fills the gap of similar products in China, it has remarkable economic and social benefits. The manufacturing technology of this product has reached the leading level in China.