球墨铸铁管是以镁或稀土镁结合金球化剂在浇注前加入铁水中，使石墨球化，应力集中降低，使管材具有强度大、延伸率高、耐冲击、耐腐蚀、密封性好等优点 的管件；内壁采用水泥砂浆衬里，改善了管道输水环境、提高了供水能力、降低了能耗；管口采用柔性接口，且管材本身具有较大的延伸率，使管道的柔性较好，在 埋地管道中能与管道周围的土体共同工作，改善管道的受力状态，从而提高了管网运行的可靠性。因此，目前我国供水行业通常采用球墨铸铁管作为主管件。

　　All flange three - pass pipe fittings - ductile pipe fittings

　　In the pipeline to connect, on both sides of socket, used to connect ductile cast iron pipe socket, intermediate flange to pipe connected with a flange.

　　Spheroidal graphite cast iron spot pipe products: plate bearing a short tube in disc tube casing of double socket three Cheng tee tube double disc tapered tube 45 DEG socket pipe socket disk T-shaped tube full bearing four-way three bearing in a four-way socket tapered pipe overall four-way socket pipe blind plug socket double disc four-way.