Few researchers have presented solids friction factor correlations for the fluidized dense phase conveying of fine particles or powders. Pressure drop for conveying can be predicted using these correlations. These correlations predict the pressure drop with minimum error margin for a definite pipeline configuration or for some specific types of conveying materials. Few researchers have applied their correlations for different pipeline configurations (of different pipeline lengths or diameters) or different conveying materials to predict the pressure drop. In this paper, different solids friction factor correlations for the fluidized dense phase conveying have been considered which are available in the literature and the behaviour of these correlations have been studied under length scale-up or diameter scale-up conditions. It has been observed that only few correlations exhibit natural pressure drop variation with change in pipeline length or pipeline diameter. © 2020 Institute of Materials, Minerals and Mining and Informa UK Limited, trading as Taylor & Francis Group.