minable e seam 可采煤层

Side e seam 侧缝

E Seam and Attachment Strength 缝线及附件强度

inside e seam 下裆缝

unworkable e seam 不可采煤层

undersleeve e seam 袖底缝

double e seam welder 双层缝焊机

roller-type E seam welding machine 辊式缝焊机

CLOSE E SIDE SEAM 埋侧骨