... :Excutive Standard standard for design,process,test:GB/T12465-2007 Flange connection:GB/T17241-1998,GB/T9115-2000 3:Main metal ... ,Limited short pipe.Carbon steel,Quality carbon steel,Nodular cast iron,Stainless steel.Q235-A,20,35,45,QT400-15,0cr18Ni9 ...