... , tooth bend, stamping elbow inside andoutside screw, pushing elbow, socket elbow ,butt weld elbow,inside screw elbow. Our elbow through ISO 9001 ... ,waterSurface TreatmentShot blasted, rust-proof black oil,Black painting,anti-rust varnish,anti-rust oil,hot galvanized,3PE coating, epoxy coating. ... 12-WP 11-WP 22-WP 5-WP 91-WP911 low temperature steel: ASTM/ASME A402 WPL3-WPL 6 high performance steel ...