Currently, the spirally welded pipe mill train produced by TYHI is the most advanced pipe equipment made through our own effort in China . The spirally welded pipes produced with the help of such equipment conform to API and the requirements of the state to welded pipes for transportation gas from the west to the east. During the Invitation for Bid for pipe making equipment of transportation of gas from the west to the east, TYHI won the bid for designing and making all the five spirally welded pipe mill trains. During the design it absorbed the advantages of spirally welded pipe equipment both at home and abroad. Its forming process was of three roll formation plus external control roll adjustable formation”. The welding process was of double wire submerged arc automatic welding”. For the raw material quality the welded pipes produced by this train were of those with X70 18mm thickness andmaximum diameter