... welded to the main pipe. And is connected to the branch or other fittings such as nipple, thread plug,instrument and ... valve by Butting-welding, socket-welding and thread. TypeConnected typeGB19326 Socket weldedGB19326 Pipe threadGB19326 Butt-weldedStandardSOL (MSS SP-97,Q/ ... Nipple,Hexagonal Nipple,etc ♥We are manufacturer of steel pipe&fittings, like 45deg/90deg/180deg elbow,equal or reducing ...