The Flexaust Flexadux R-3 PVC duct hose, used for industrial ventilation, dust removal, and fume exhaust applications, is a heavyweight, clear PVC hose, reinforced with a coated spring steel wire helix. It resists chemicals, moisture, and both internal and external abrasion, and is flexible and compressible for easy manipulation and installation. A temperature range of 20 to 160 degrees F makes it suitable for applications such as dust removal and ventilation. This PVC duct hose has a wall thickness of 0.035 inch (for diameters up to 3 inches) or 0.045 inch (for diameters from 4 to 12 inches), is clear for viewing interior flow, and is made from materials that conform to U.S. Food and Drug Administration (FDA) CFR (Code of Federal Regulations) Title 21 requirements for use in food-grade farms, food processing applications, and pharmaceuticals.Duct hoses are flexible or rigid tubes that convey gases, liquids, and lightweight bulk materials from one location to another. They are made from an array of materials that range from polyurethane and thermoplastic rubber, to PVC and aluminum-coated fiberglass fabric, and are typically reinforced with a steel wire or rigid plastic helix, also known as a “spiral.” Duct hoses are secured with hose clamps or U-bolts, and two pieces of hose are joined with a hose connector. Common applications for duct hoses include heating and cooling, ventilation, fume and smoke exhaust, vacuum cleaning, moving chips and shavings, handling bulk packing materials, and water and waste discharge.Flexaust manufactures flexible hose, metal ducting, and accessories for industrial and commercial applications. The company, founded in 1938 and headquartered in San Diego, CA, is part of the international Schauenburg Group.