Question: In a part with a pipe feature created (not using Pro/PIPING, but simply with Feature>Create>Pipe), a centreline is created by the pipe feature, and this centreline becomes hidden in part mode when you set display to No Hidden, but this hiding does not carry through to the drawing.  How do we hide the centreline in the drawing?

This is the config option that works for Pro/PIPING pipes:
hlr_for_pipe_solid_cl
no, yes
Controls display of pipe centerlines. If set to "yes," hidden line removal affects pipe centerlines. If set to "no, it does not. Operates only on pipes created in Pro/PIPING, not on pipe features in a part.

Answer: Add the pipe feature to a layer in the Part.  When you blank that layer only non-solid geometry can be blanked, therefore only the pipe centreline disappears.
 

Thanks to:
Brian S. Lynn	blynn@weil-mclain.com
Vivek  S Joshi	"vivek_joshi" <vivek_joshi@onwardgroup.com>
Colin Down	colin.down@oxinst.co.uk
Jason Biter	"BITER, JASON" <JASON.BITER@littletikes.com>
Julian Wooster	JulianWooster@Solectron.com
Trevor Hall	trevor.hall@ps.ge.com
Lee McGee	"McGee, Lee" <Lee.McGee@alcoa.com>
Florin Nijloveanu	"Nijloveanu, Florin" <FNijloveanu@OrionBus.com>
Doug Morse	"Morse, Doug" <DMorse@helixtechnology.com>
Ronald J. Huber	huber_ronald_j@cat.com
Keith Jones	CUMMINS
Steven K. Jones	"Jones, Steven" <skjones@leevalley.com>