Spading Pipeline
What is a pipe trench? 3
What is tube in tube and oil tube?
Insert a board (in the form of a table tennis club) into the tube with proper pressure for about two seconds. Provides positive isolation towards water flow.
Glasses (usually worn 24 hours a day) are also worn and can be rotated in an open or closed space.
Both of these terms mean sword.
You slide between the tubes on a solid board (looks like a ping pong racket).
up to
Where the board contains the file, it is called a board,
Valves work on the same principle.
I think this is where they flatten the end of the tube so that it can be sealed.
