... steel,stainless steel,etc 3)standard:ANSI B16.5 4)WT:#150-#2500 5)API,ISO,CE,etc size 1/ ... F5,F9,F91,Etc)QualificationISO9001:2008 Quality Mangement System Certificate,ISO 14001 Environment Mangement System Certificate,OHSAS18001 Occupational Health & Safety ... China National Petroleum Corporation.We are also qualified the standard material supplier of China National Offshore Oil Corporation and ...