A pressure vessel can be defined as any container of fluid with a pressure differential between the outside and the inside of the container. Their presence is inevitable in various types of power plants, chemical and process plants. Pressure vessels often have a combination of high pressures together with high temperature operating conditions, and in some cases flammable fluids or highly radioactive materials. Because of such hazards, it is imperative that the design should ensure the states of no-leakage or leak-before-catastrophic break. In addition, these vessels have to be designed carefully to cope with the operating temperature and pressure. This book presents recent advances in the design and usage of pressure vessels and piping components.