riser pipeline vs riser

riser pipeline and riser both are nouns.

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

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

Other synonyms of riser pipeline include riser main, riser pipe.

riser pipeline (noun)	riser (noun)
a vertical pipe in a building	structural member consisting of the vertical part of a stair or step
	a vertical pipe in a building
	a person who rises (especially from bed)