YD/T 841.3-2008.Plastic Pipe for Buried Communication Conduit Part 3:Double-Wall Corrugated Pipe. 1范...
YD通讯标准
YD通讯标准
YD通讯标准
YD/T 841.3-2016 地下通信管道用塑料管 第3部分:双壁波纹管
YD/T 841.3-2016.Plastic duct for telecommunication underground conduit Part 3: Double-wall corrugate...