Internal coating used in high pressure, large diameter and long distance gas pipeline has two main functions, one of them is anti corrosion and the other is drag reduction.
高压、大口径、长输天然气管道采用内涂层主要具有两大功能，一是防腐蚀，二是减阻。
Once the throughput, pipeline route and oil kinds are defined, the main factors, which influence the total cost of isothermal oil pipeline, are material, diameter and design pressure.
指出在管输油品、线路走向及输量等已定时，影响等温输油管道总费用的主要因素有管材、管径及操作压力。
Main points in design and construction concerning the large diameter nodular cast iron pipeline are described by means of Taiyuan water supply engineering from the Huanghe River.
介绍了大口径球墨铸铁管的主要性能特点，并通过黄河水源太原市城市给水工程，就大口径球墨铸铁管在设计与施工中的要点进行了论。
应用推荐