Techniques and calculation tools which are useful in plant hydraulic designs or operations involving process or utility lines are presented in this volume of vapor-liquid equilibrium flash vaporization (EFV) and fluid flow. The EFV and flow equations are first presented via consistent principles of thermodynamic laws. Physical laws governing conservations of mass, force/momentum and heat with an equation of state are interwoven with the thermodynamic treatment in presenting of analytical equations. Reversible and irreversible analyses of a process lay the basis for understanding Bernoulli's law, Hagen-Poiseuille law, Darcy's velocity head equation, Fanning or Darcy friction factors, flow coefficients, plus incompressible and compressible fluid in piping or internal restrictions. Sizing of orifices, nozzles, pressure relief valves and control valves, net expansion factors, sonic gas flow, hydro-static pressure test, etc. are also presented. This treatise of practical plant piping fluid-flow topics covers the process of closed and open systems. Illustrated applications include the area of practices in pressure system safety relief, vessel or piping pressure relief, sizing fluid movers and hydraulic power recovery trains, calculation of pressure profiles in a piping circuit, the atmosphere, fired heater box and stack. Examples are developed to illustrate means for solutions for practical problems using these tools. Dr. John Cheng had been working in the hydrocarbon process industry in computer simulations, process or mechanical designs, engineering and construction capacities on chemical plants, oil refineries, pipe lines for engineering and construction companies for a total of more than 40 years. The field of fluid movement and plant piping hydraulics from the engineering aspect interests him to put together this book to reveal certain commonalities and solutions from the respective trades. Dr. Cheng received his PhD in Chemical Engineering from Texas Tech University in 1976.