steam line vs pipe

steam line and pipe both are nouns.

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

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

steam line: a pipe conducting steam
pipe: a long tube made of metal or plastic that is used to carry water or oil or gas etc.

Other hypernyms of steam line include pipage, piping.

steam line (noun)	pipe (noun)
a pipe conducting steam	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