tube, conduit, duct, channel, pipeline, hose, main, line, siphon, spout, vent, flue, cylinder, straw, stem, exhaust, drain, gutter, trough, passage, tubing
tube, conduit, duct, channel, pipeline, hose, main, line, siphon, spout, vent, flue, cylinder, straw, stem, exhaust, drain, gutter, trough, passage, tubing