Numerous developments have taken place in centrifugal pumps to transfer liquids for different applications in efficient manner. A safe, cost effective & efficient operation at rated capacity, efficiency and high reliability is the basic requirement of pumps. To meet the objective, the book deals with basic concept of theory added working principle, different type of pump & their application, constructional features, design guide lines & rotor dynamics, selection, erection, trouble diagnosis & remedial actions in abnormal situations. The metallurgical requirements and developments for pump components had been discussed briefly for acquaintance of plant engineers to help in selection &, procurement. Concept of NPSH, specific speed, sealing system and Characteristic curves of pump with the help of graphs, theoretical formulae, sketches and examples may promote understanding in field applications. Operation and Maintenance philosophy is presented to cover wide domain of pumping system The systematic and predictive maintenance programs & their applications are discussed related to centrifugal pumps. A brief out line discussions are presented on electric system involved in pump installation and maintenance. Since, alignment of pump, especially the multi stage pumps with driver (motor or steam turbine) plays a vital role in smooth operation and machine life, author has dealt separately the alignment methods and practices with illustrative practical examples. The book is formatted in the form of Work Book to help the working engineers as reference at any stage of their task performance.