Friction Coefficient Comparison between Different Ductile Iron Pipe Inner Linings by Hydraulic Model Test

• 張 竣超

Student thesis: Doctoral Thesis

Abstract

Normally the friction characteristics of ductile pipe is described with friction coefficient Most hydraulic engineers estimate water head loss by C number friction coefficient However C number data in textbook and literature usually is estimated by ductile pipe material Actual friction is not certain For investigating friction coefficient of ductile pipe this research performs friction coefficient comparison between civilian produced cement mortar and recently developed epoxy resin powder ductile iron pipe inner linings with experiments The experimental results show that the C number of cement mortar inner lining is between 137 5 and 147 0 and epoxy resin powder inner lining whose C number is between 137 5 and 147 0 has lower friction The f number of cement mortar inner lining is between 0 0151 and 0 0170 and the f number of epoxy resin powder inner lining is between 0 0132 and 0 0170 The f number which varied with Reynold number has maximum variation of 12 3% when flow velocity is 3m/s By Moody diagram the e number of 300mm diameter ductile iron pipe with cement mortar inner lining is 0 03mm and similar to the e number of smooth concrete (e = 0 025mm); the e number of 300mm diameter ductile iron pipe with epoxy resin inner lining is 0 0031mm and similar to the e number of smooth PVC pipe (e = 0 0025mm) The analysis show that the C numbers of the tubes are not constant and varied with temperature and flow velocity Since their relationship with Reynolds number is not obvious C number analysis produces larger error and is only useful for in-situ quick and rough estimation The f number derived by Darcy-Weisbach equation is certainly varied with Reynolds number relative roughness and temperature Calculating friction loss by deriving f number is quick and easy Hence future design plan and hydrological analysis performed by tap water company should ensure safety parameter margin by Hazen-Williams equation The examination with Darcy-Weisbach equation under different conditions should be performed for better accuracy of design The intelligent pipe network design should be evaluated by Darcy-Weisbach equation for better accuracy Keywords: Tap water Pipe material Inner lining Friction resistance
Date of Award 2019 English Jan-Mou Leu (Supervisor)

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