Drill Pipe, Gate Valve, Petroleum Equipment manufacturer / supplier in China, offering API 5CT OCTG Casing Tubing J55 K55 N80-Q R1 Stc Thread, API 5CT Casing Tubing J55 K55 N80-1 R3 Ltc Thread, API 5CT Seamless Tubing J55 K55 N80-Q R2 Btc Thread and so on.