... Standard:ASME,BS,GOST,eg seamless pipe fittings,45/90/180 degree elbow sizeSeamless:from 1/2" to 24"Welded: ... customer requirements)degree22.5 deg, 30deg,45 deg,90 deg,180 deg, 1.0D, 1.5D, 2.0D, 2.5D, ... ,316L,321,ect)Alloy steel(ASTM A234 WP12,WP11,WP22,WP5,WP9,WP91, ect)qualificationISO9001:2008 ,ISO 14001 OHSAS18001 , API , ... Steel Elbow Chemical Analysis seamless pipe fittings,45/90/180 degree elbow