... -diameter and reducing-diamater bend standard:GB,ISO,ANSI ,JIS,DIN butt-welding equal-diameter and reducing-diamater bend 45/90/180 ... degree seamless an welding standard:GB,ISO,ANSI ,JIS,DIN1 size:1/2"-72"2 type : Long-radius or ... welding5 standard:GB,HGJ,SHJ,SY,DL,ISO,ANSI ,JIS,and DIN6 wall: STD ,SCH40,SCH807 Others: acquire ISO9001 1:2000 certification ...