Ключевые слова: black, bolt, box, building, conduit, connection, construction, crane, cross, drain, element, engineering, faucet, fitting, flange, flow, fuel, gas, gasoline, icon, illustration, industrial, manometer, metal, metallic, oil, part, pipe, pipeline, piping, plumbing, pressure, set, sewerage, shape, sign, silhouette, steam, steel, stream, symbol, system, tap, technical, technology, tube, valve, water, welding, wheel,