pipework vs flue

pipework and flue both are nouns.

Word	Noun	Adjective	Verb	Adverb
pipework	Yes	No	No	No
flue	Yes	No	No	No

As nouns, flue is a hyponym of pipework; that is, flue is a word with a more specific, narrower meaning than pipework:

pipework: the flues and stops on a pipe organ
flue: organ pipe whose tone is produced by air passing across the sharp edge of a fissure or lip

Other hyponyms of pipework include flue pipe, labial pipe, organ stop, reed pipe.

pipework (noun)	flue (noun)
the flues and stops on a pipe organ	a conduit to carry off smoke
	organ pipe whose tone is produced by air passing across the sharp edge of a fissure or lip
	flat bladelike projection on the arm of an anchor