非开挖PE穿管修复法的允许缩径

Permission Reducing Diameter of Non-excavation PE Pipeline Inserting Renovation Method

天然气的热值高于人工煤气,PE管的内壁光滑,其摩擦阻力远低于钢管、铸铁管。因此,在非开挖穿管修复中,PE管径允许小于原煤气管道的管径。在理论上,从水力计算公式阐明了非开挖PE穿管修复法允许缩径的理论依据,其主要理由是改造后燃气压力的升高,而PE管内壁表面当量粗糙度系数对允许缩径的影响可忽略不计。

Caloric value of natural gas is higher than manufactured gas. PE pipe＇s inside wall is slippery and its friction resistance is further below steel pipe＇s and cast iron pipe＇s. Hence PE pipe diameter is allowed to be less than original gas pipe diameter under non-excavation inserting renovation. In theory, the article illustrates the theoretical basis of that method by hydraulic calculation formula. The mostly reason is that the influence of PE pipe inside surface effective roughness coefficient to permission reducing diameter can be neglect when the gas pressure is higher after reconstruction.