Because of the much thick wall of large capacity boiler drum, the pressed and weld longitudinal seam is used to manufacture the drum shell ring.
由于大容量电站锅炉汽包的壁较厚，所以在汽包筒节制造时常采用压制成两个半圆瓦片再焊接而成的方法。
2
Analyses the cause for the crack resulting from the non-fusion in the longitudinal weld seam of a power plant boiler cylinder, and suggests corrective actions to eliminate the defect.