You can also just use a north-facing window, a neutral background and white foamcore or mirrors. For more punch, you can cover the foamcore with aluminium foil.
In a simple, uncomplicated nutshell: the
main point is that you just don't want the main light to come from the front, on the same axis as the camera. All the more so if the pipe is rusticated/sandblasted, because frontal lighting will wash out the texture (which is why we use frontal lighting to take portraits of old people: it hides the wrinkles); for textured surfaces you want the light to come from the side (raking) so as to emphasise said texture. Ditto for pipes that sport plateaux rims, such as the ones the OP's showcasing here.
Even for smooth pipes or surfaces (i.e. stems) you don't want frontal light because of the ugly glare.
You don't have to read all the epistle, but I reckon the pictures' footnotes would help. Feel free to read the whole thing, if you so want, though:
lunaris.diamantstudios.ca