X80电阻焊管线管
X80 grade electric resistance welding linepipe
地下管线管理
underground pipeline management
Management of Underground Pipelines
地下管线管理系统
underground pipeline management system
钩形集极晶体管管线
hook collector transistor
管线板材
plate steel for pipe-making
管线管理系统
tubeline management system
海底无缝管线管
submarine seamless line pipe
筛管＋盲管完井
screen+blind pipe completion