DUXAOIL / DURALITTE It's a company dedicated to the manufacture of connections and lines for fluid conductions. We have certifications ISO 9001, API 5CT and API 11B. Product List: Couplings Tubing and Casing. Sucker Rod Coupling. Pup Joint. Rotary Shouldered Subs. Hammer Union. Forged Accessories. Manifolds. Swage Nipples. Valves. Special Developments.