... elbow, tooth bend, stamping elbow inside andoutside screw, pushing elbow, socket elbow ,butt weld elbow,inside screw elbow. Our elbow through ... systems, mainly manufacture elbow, tee, reducer, cap, flange, cross, nipple, socket fitting, expansion joint and other series products. elbow:are widely ... with GB in China, API in US, and CE in Europe, DIN in Germany. The knife gate valves, parallel slide valves ...