A couple of simple objects can go a long long long long way. All of these pipes are constructed in a modular manner. There are two pieces, a straight one and a bent one (wipe that smirk off your face). The meshes were made using Blender, then textured with Substance painter, then imported into Unity.
I really enjoy placing meshes like this to design things. It’s like using virtual lego, only you have an unlimited amount of it, and you don’t have to go rummaging through your collection to find that much needed flat yellow two-er.