... of producing ,developing and selling oil pipes and their accessories, steel pipe fittings and other down well ... Units Produced(Previous Year) Tubing Coupling, Tubing Pup Joint/Crossover, Casing Coupling, Casing Pup Joint/Crossover, Centralizer ... Oil Tubular Goods Tubing Coupling & 2011/05/25 Inspection Report China National Quality Supervision, Testing and Inspection Center Of Oil Tubular Goods Casing ...