异径管也叫大小头，两端管口直径不同，用于连接不同直径的管子或法兰进行变径。

Different-diameter pipe size head, also called tube diameter at different, used to connect different diameter of pipe or flange diameter changes on.

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管件类： 弯头、三通、四通、活接头、卜芯、大小头、管帽、堵头、内丝、外丝、翻边、异径管。

Pipe series: Elbow, tee, cross, movable joint, Bu core, reducer, pipe cap, choke plug, inside the wire, outside the wire, turned-over edge, increaser etc.

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