A flexible, tubular item of light wall construction. it must have single or multiple layers of nonmetallic material, but may contain metal wire reinforcement, foil type liner, and/or woven or braided cover. it is designed to convey under low pressure gaseous material, such as air and fumes, and light weight solid materials, such as dust, powders, and fibers. for items with couplings, see hose assembly, air duct. for items of sleeve section design rated for high pressure use, see sleeve, seal, coupling. excludes hose, nonmetallic.