petrol line vs pipe

petrol line and pipe both are nouns.

Word	Noun	Adjective	Verb	Adverb
petrol line	Yes	No	No	No
pipe	Yes	No	Yes	No

As nouns, pipe is a hypernym of petrol line; that is, pipe is a word with a broader meaning than petrol line:

petrol line: a pipe that carries gasoline from a tank to a gasoline engine
pipe: a long tube made of metal or plastic that is used to carry water or oil or gas etc.

Other hypernyms of petrol line include pipage, piping.

petrol line (noun)	pipe (noun)
a pipe that carries gasoline from a tank to a gasoline engine	a long tube made of metal or plastic that is used to carry water or oil or gas etc.
	a tube with a small bowl at one end; used for smoking tobacco
	the flues and stops on a pipe organ
	a tubular wind instrument
	a hollow cylindrical shape