Using a 1/16" drill bit, drill a hole in the middle of the cross section tube above. This will allow gas to escape during welding."
使用1 / 16“钻头，钻一个孔在上面管中间的横截面。这将使天然气逃脱焊接过程。
2
According to the size and height of the falling rock block, the thickness of the circular tube can be determined, which can provide the foundation of designing the escape passage system.
同时，根据岩块大小和下落高度，可以通过计算凹陷变形而确定圆管厚度，为逃生管道的安全设计提供依据。
3
Heat the test tube further, and a yellow gas will be seen to escape into the air.