Haiyan Zhongda Special Steel Co.,Ltd is important domestic production base of metal electronic materials(including all kinds of precision alloy and metal functional materials). The large diameter seamless stainless pipes and dual seamless stainless pipes are the key materials of the oil quantifiable and pressure vessels industry. As the group has a strict quality management system, the products has passed ISO9002 quality system testing of the China certification center for quality mark in 1998. Some of the products also passed the testing of British Lloyd’s Register Quality Assurance , the testing of EU Pressure Equipment Directive, and got the PED certificate and the CE certificate, and passed the technology assessment of China Standardization Committee on Boilers and Pressure Vessels(CSCBPV).