... , 3.PSB,long lifetime 4.CE,API,ISO certificates Cast Iron Flange blow down valve :Widely used for gas transmission pipeline ... working condition difference design,so we have to redesign the products according to your working codition. The picturs below designed before ... -HydraulicDN(NPS)1/2"~2"PN(LB)Class 150LBMain MaterialsCast Iron,GG25,GG40,HT250,HT200,QT450 Stainless Steel:CF3,CF3M,CF8 ...