... .Steel typeSteel gradeannual output/t1Oil casing Pipe, joint materialJ55,K55,N80-11000002Oil line pipeB,X42~X60(L245~L415)50003high-pressure boiler ... output/t1Oil casing Pipe, joint materialJ55,N80,L80,C90,P110850002Oil casing Pipe, joint materialJ55,N80,L80-1,C90,T95,P110,Q125,9Cr ...