Ключевые слова: abstract, background, banner, bolt, chemical, color, colorful, conduit, connection, construction, control, drain, element, engineering, equipment, factory, faucet, fluid, fuel, gas, gasoline, icon, illustration, industrial, industry, isolated, liquid, metal, natural, object, oil, petroleum, pipe, pipeline, piping, plumbing, power, pressure, pump, shape, sign, steel, symbol, system, tap, technology, tube, valve, water,