妖精视频在线观看18,妖精视频网站在线观看,黄色网站妖精视频,妖精视频成人免费无码区

High polymer coated pipe using process of spray or spray + extrude one or multi-layer PE, EP on HFW, SAWH, SAWL, SMLS pipe surface after internal and external sandblasted or shot blasting pretreatment and MF heating etc.

Main usage: oil and natural gas transportation pipeline project、underground of urban gas steel pipeline、urban water supply project.