helically-welded case

例句：

1. 1.The helical welded case is a critical component of the new design.
   螺旋焊接容器是新设计中的关键部件。
2. 2.The helical welded case was used to transport the heavy equipment.
   螺旋焊接容器用于运输重型设备。
3. 3.The helical welded case has been tested for leakage and strength.
   螺旋焊接容器已测试过泄漏和强度。