Membrane technology being low-energy consuming and environmentally friendly is considered to be a new generation of the sustainable processes. Diversification of the spectrum of their applications in particular for processing aggressive fluids at elevated temperature; for separation of liquids with shear- dependent behaviour etc. require further development of the pressure driven membrane processes such as reverse osmosis, nanofiltration, ultrafiltration and microfiltration. Implementation of these processes are often hampered by existing techniques of process calculation and design, therefore this book focuses on modeling, development of the process- type calculations and analysis of the pressure driven membrane operations.