一级黄色毛片-一级黄色大毛片-一级黄色a视频-一级黄色a毛片-一级黄色a-一级黄片毛片

雙扣聚氯乙烯增強管發展初期，PE管的用量遠遠小于PVC管，鋼帶管主要原因是經濟性。當時高性能PE管材料還沒有被開發出來，只能使用性能相當于PE63等級的PE材料，由于強度低，同樣條件下PE管的壁厚要比PVC管大1倍以上，不僅材料成本高且只能在較低壓力、較小直徑管材上應用，否則壁厚太大無法使用。隨著研發力度不斷加大，新一代高強度管材專用PE料不斷涌現，不僅出現PE80級，還出現PE100級產品。材料升級換代使PE管各種應力顯著提高，管壁厚度越來越薄，甚至低于PVC管。

At the beginning of the development of double buckle PVC winding pipe, the consumption of PE pipe was far less than that of PVC pipe, and the main reason of steel pipe was economy. At that time, high-performance PE pipe material had not been developed, only PE material with performance equivalent to pe63 grade could be used. Due to low strength, the wall thickness of PE pipe was more than twice that of PVC pipe under the same conditions, which not only had high material cost, but also could only be applied to pipes with lower pressure and smaller diameter, otherwise the wall thickness was too large to be used. With the continuous increase of research and development, a new generation of special PE materials for high strength pipes are emerging, not only PE80 grade, but also PE100 grade products. With the upgrading of materials, all kinds of stress of PE pipe increased significantly, and the thickness of PE pipe wall became thinner and thinner, even lower than that of PVC pipe.

雙扣聚氯乙烯增強管是由HDPE同時擠出的波紋外壁和一層光滑內壁一次熔結擠壓成型的，管壁截面為雙層結構，其內壁光滑平整，外壁為等矩排列的具有梯形中空結構的管材。

Double buckle PVC winding pipe is formed by one-time fusion extrusion of corrugated outer wall and a layer of smooth inner wall extruded by HDPE at the same time. The section of pipe wall is double-layer structure, the inner wall is smooth and flat, and the outer wall is trapezoidal hollow structure pipe with equal moment arrangement.

具有優異的環剛度和良好的強度與韌性，重量輕、耐沖擊性強、不易破損等特點，且運輸安裝方便。管道主要采用橡膠圈承插連接(也可采用熱縮帶連接)。由于雙扣聚氯乙烯增強管的特殊的波紋管壁結構設計，使得該管在同樣直徑和達到同樣環剛度的條件下，用料(HDPE)省。但受到生產工藝限制，目前國內能生產的大口徑也只有DN1200，使得其推廣受到一定的限制。

It has excellent ring stiffness, good strength and toughness, light weight, strong impact resistance, and is not easy to be damaged, and easy to transport and install. The pipes are mainly connected with rubber ring socket (or heat shrinkable tape). Due to the special corrugated pipe wall structure design of double buckle PVC winding pipe, the material (HDPE) is saved under the condition of the same diameter and the same ring stiffness. However, due to the limitation of production process, the current domestic production of large caliber is only DN 1200, which limits its promotion.