一个人免费视频www,亚洲av第一成肉网肉片av,亚洲熟女一区,二区,国产一区二区三区四区精华

Q235B and Q355B steel pipes are widely used in construction for water supply and drainage pipelines in buildings, heating pipelines in residential quarters, and structural support pipes for temporary engineering, as their good weldability and mechanical stability meet the basic pressure-bearing and installation needs of civil scenarios. In municipal infrastructure, they are applied to urban water supply networks, rainwater drainage pipes, and low-pressure gas transmission pipelines, benefiting from cost-effectiveness and reliable adaptability to outdoor environments. They also find use in machinery manufacturing (for non-high-pressure hydraulic system pipelines and equipment protective sleeves), the agricultural sector (for farmland irrigation pipes and sprinkler system pipes), and light industrial production (for material conveying pipes in food processing auxiliary equipment), serving as a versatile material for general industrial and civil medium transmission and structural support scenarios.