Absolute Roughness Values and Sensitivity to Liquid and Gas Pipeline Calculations

Abstract

An important variable considered in the sizing and design of pipelines is the absolute roughness of the pipe, with a default value of 1800 micro-inch (or 0.04572 mm) generally used in the industry. This value appears to have originated from studies carried out more than half a century ago while pipe manufacturing and treatment methods have since become more advanced. In this study, the absolute roughness of various commercial steel pipe samples of different diameters that had been manufactured and treated with various methods was measured using a Mitutoyo SJ-201 surface roughness gauge. All pipe roughness values recorded were less than the generally used 1800 micro-inch (or 0.04572 mm) value. This study also examines the impact of absolute roughness values in the design of a liquid and gas pipeline case study with results indicating that gas pipelines are more sensitive to changes in absolute roughness value.