In March 2010,the survey team of China Chemical Equipment ISOC came to our company for checkup of geting certificate. All system’s  files which  was about design quality ensured and company’s operating were included. Survey team gave positive judgements ,and awarded the Design License of pressure vessel (Class A2) to Yongsheng on May 22th 2010,which means Yongsheng Machinery had the design’s qualification of medium/low pressure vessel of the third kind since that time.