In the paper an experimental verification of the original, multi-stage transformation method describing laminar and turbulent flow of purely viscous, non-Newtonian fluids in straight and curved pipes of elliptic cross-section has been shown. The flow of polymer solutions in straight pipes of elliptic cross-section can be generalised on the pseudo-Newtonian flow where the dimensionless numbers c(f) and De are analogues to those describing real Newtonian fluid flow. The method can be generalised on the non-Newtonian flow in curved pipes of elliptic cross-section.