Ключевые слова: background, cable, canalization, circle, communication, conduit, connection, construction, corrugated, curves, electric, electrical, electrician, electricity, energy, flexible, gray, green, industrial, industry, installation, isolated, isolation, line, manufacturing, pipe, pipeline, pipework, plastic, plumbing, power, protection, protective, pvc, ring, round, sewage, sewer, sewerage, stack, supply, tube, tubes, tubing, tubular, underground, wire, wiring,