China standards-DIN standards-US standards

hello from Zhaoqing China,(home base is Alabama) I'm over a design group designing and building an alum. plant ($500 mill job). I have found lots of info on DIN standards but nothing on China. I am installing used mills from the states, US standards, and new mills from Germany. I am making a chart for my Hong Kong contractor (hong Kong is all BS standards)the chart I found on this site compairing USA and european is excelant except need on more column, CHINA as far as I can tell China pipe is almost the same as US pipe.the chart I'm making up has US-CHINA-DIN so if one wants to say look up 1/2" sch 40 US,= DN 15 or 22.0x2.0 (which is what I see the most on the German dwgs) and the next column is China would be ,= DN15(dia. sign) 21.3x2.75.we are only a year behind right now,and just fired our second contractor. thanx for any help. piper long way from home....pipepat