... 2-100 Casing pipe J55 N80, P110API SPEC 5CT-- oil pipe for oil well, Coupling Cylinder60-630×1.53-40 Low and medium pressure ... boiler tube 10,20GB3087-1999- for Low and Medium Pressure ... for boilers and overheating14-426*1.5-4.5 line pipe 5L GR.B, X52,X60 API-for petroleum,natural gas, industrial dilivery(gas,water,oil ...