My son just called me; he is a pipeline welder. Here is what he retaught me.
The oil line is up to 42 inches in diameter. They run one fuel through it for so many hours then shut the line down to change fuels.
The change over requires pipe prepping first. Every so many miles is a pipe sticking up from the main line. It has several short lines branching off from it giving it the appearance of an upside down Christmas tree.
One of the branches is opened to launch a pig. A pig is a leather ball looking like a football that barely fits in the pipe. Air pressure is applied forcing the ball to scrub the inside of the pipe. Thus the Xmas tree is called a “Pig Launcher”.
Then nitrogen is pressurized through the pipe to do a final chemical cleaning. Then finally they begin pumping a new fuel through the clean pipe.
So this does mean not only is auto traffic, some fork lifts, etc. and gasoline powered tools being shut off but also all air travel. Brace yourselves Folks and don’t get hit too hard by the proverbial Pig Launcher!
The country may be brought to its knees.