high precious pipe , smooth surface NOSteel pipeStandardSteel gradeSpecificationOD×WAL×LENGTH (mm)1Oil pipeAPI5CT- ... ,20,Q295,Q34560~180×3.5~25×4000~120005high-pressure boiler tubeGB5310-199520G,20MnG,25MnG,12Cr1MoVG,15CrMoG,P9160.3~180×4 ... ~25×4000~120006lower/medium-pressure boiler tubeGB3087-199910,2060.3~180×4~25×4000~120007ydraulic pillar ...