Abstract
The impact of applying advance metrics technology in quantifying circular pipe surface roughness insures precise and cost effective piping designs for the chemical and petroleum industries. Flow test validation of the results from the Dektak3 ST Surface Profiler® and the Hommel Tester T 1000® was performed in order to warranty that such metrics technology could quickly and effectively substantiate the effects of surface pipe roughness on friction pressure losses, and energy characteristics.
The metrics test set consisted of nine joints of 2-7/8-inch OD, chrome 13 tubular pipe sections having varying internal diameters that consists of: (1) plastic coated (IPC 800) tube; (2) electropolished Cr13 with heavy metal removal; (3) electropolished Cr13 with moderate metal removal; (4) four electropolished Cr13 samples with low metal removal; (5) mill finished Cr13 descaled by garnet blasting; and (6) mill finished Cr13 chemically descaled tube, no electropolish. The Mechanical and Fluids Engineering Department of Southwest Research Institute (SwRI) tested the pipes for the purpose of measuring pressure drop, and thereby evaluating the friction factor created by wall surface roughness in each pipe. Each section were prepared and tested for surface roughness according to the DIN 4768 (Deutsches Institut für Normung C.V.) specification using Dektak3 ST Surface Profiler® and the Hommel Tester T 1000® at the University of Louisiana. Friction-factor test results using profiling instruments with those derived from the measured flow results using the Southwest Research Institute's flow facility validated test results as predicted by the Moody and Colebrook-White equations.
