... 3.PSB,long lifetime 4.CE,API,ISO certificates Cast Iron Flange blow down valve :Widely used for gas transmission pipeline ... HydraulicDN(NPS)1/2"~2"PN(LB)Class 150LBMain MaterialsCast Iron,GG25,GG40,HT250,HT200,QT450 Stainless Steel:CF3,CF3M, ... equipment design andmanufacturing licenses, as well as national pressure piping components, the security certificate of registration (AZ).When facing both ...