Using solid strand electrical wire is nothing new in modeling. This chart shows from No. 56 to No. 6 wire and what the conductor diameter is and then what this dia is in Z, N, HO, S and O scales. I referred to the “Solid and Stranded Conductor AWG Chart” from Calmot Wire and Cable to make this.
Copper solid strand electrical wire with the insulation and some super glue allows you to make really small, scale looking plumbing.
Find the wire with the right dia. for your specific use and pull off the insulation in one piece. Then slice the insulation into small “doughnuts” (this is actually the hardest part … getting the doughnuts evenly sliced). Bend the wire paying attention to the “elbows” .. then slide the doughnuts up to form the ends of the elbows and a drop of superglue not only seals them to the wire but will form a slight fillet.
These make EXCELLENT plumbing fixtures at scale.