API 5000What does it refer

api 5000Complete Range Of API 5000 Rtj Flange & API 6A Integral Flange, API Plate Flanges At Affordable Price, Renown Suppliers Of API 6A Flange Studs And API Type 6b Flange In India.API 6A Type 6B 5000 PSI Weld Neck & Blind Flanges Manufacturers & suppliers in India Hh pressure steel flange, forged flanges, API 6A Type 6B 5000 PSI Weld Neck & Blind Flanges