Shuangda Valve CO.,LTD (SDV) located in Wenzhou city, Zhejiang Province in China, which was established since 1992. SDV covers an area of 70000 square meters,with staff of 500 people including 16 engineers. The company has CAD computer design center to creat an a sound quality inspection institutions. We took lead to pass the ISO9001:2000 quality assurance system certification to inspect and ensure the quality in the entire process . After many years of development, SDV forms into a trade and industry one of the large-scale joint-stock enterprises, and sets up a branch in Lishui with larger size.