riser pipeline vs riser main

riser pipeline and riser main both are nouns.

Word	Noun	Adjective	Verb	Adverb
riser pipeline	Yes	No	No	No
riser main	Yes	No	No	No

As nouns, riser pipeline and riser main are synonyms defined as:

Other synonyms of riser pipeline include riser, riser pipe.

riser pipeline (noun)	riser main (noun)
a vertical pipe in a building	a vertical pipe in a building