... .Steel typeSteel gradeannual output/t1Oil casing Pip, joint materialJ55,K55,N80-11000002Oil line pipe B,X42~X60(L245~L415)50003high-pressure boiler ... )No.Steel typeSteel gradeAnnual output/t1Oil casing Pipe, joint materialJ55,N80,L80,C90,P110850002Oil casing Pipe, joint materialJ55,N80,L80-1,C90,T95,P110 ...