中文字幕在线观看,无套内射视频囯产,中文字幕理伦午夜福利片,野花社区在线观看视频

EN10210/S355 steel pipes (compliant with EN10210 standard, S355 as the core grade) are widely used in construction engineering for structural support pipes of high-rise building steel frames, temporary bridge load-bearing pipes and prefabricated component connecting pipes; applied in machinery manufacturing for equipment bases, medium-load transmission shafts and hydraulic support cylinders; used in municipal infrastructure for urban road guardrail uprights, street lamp pole main pipes and drainage system pressure pipes; suitable for engineering machinery sector for loader boom pipes, excavator chassis support pipes and bulldozer hydraulic system auxiliary pipes; and also adopted in industrial fields for low-to-medium pressure fluid transport pipelines (such as factory cooling water pipes and compressed air transmission pipes) and light industrial equipment structural pipes.