Ключевые слова: blue, building activity, circle, conduit, construction, construction industry, construction material, construction site, cylinder, cylindrical, development, diameter, distribution, duct, hardwearing, hole, in a row, industrial, industry, infrastructure, large group of objects, length, long, manufacturing, pipe tube, pipeline, plastic, plumbing, polymer, pvc, resistant, round, smooth, stack, stacked, storage, supply, tube, tubing, water pipe,