The new type of all-welded plate & shell heat exchanger combining the advantages of plate, shell & pipe heat exchanger has been applied in industry and shipbuilding.

The setting parameters of the three-roll bending plate internally -sup porting spiral welded pipe mill are critical for ensuring satisfactory and consistent quality of the welded pipe formation.

For the main defects which affect spiral welded pipe quality, the material plate quality effect to strict specification pipe production is discussed, and the solving method is proposed.