**1. Introduction**

#### **1.1 Significance of vacuum and vacuum vessel**

 The word "vacuum*"* comes from the Latin word "vacuus" which means empty or void of stuff. The vacuum categories include natural vacuum and artificial vacuum. Space is a region with supreme zero pressure from a natural vacuum. A perfect or entire vacuum, which suggests an area that is entirely void of matter, is unachievable on earth, but it is possible to generate and hold the lower pressure region referred to as an artificial vacuum by means of a vacuum vessel and vacuum generation pump. The objective of artificial vacuum generation techniques is to simulate the vacuum pressure environment. A vacuum in space can have a pressure less than 760 Torr.

 A vacuum vessel is a compact, rigid, closed chamber in which air and other gas molecules have been evacuated by a vacuum pump. A vacuum vessel isolates the partial vacuum region from the outside atmosphere. The lowest pressures inside the vessel is reached by using modern vacuum pumping strategies where large amounts of molecules are evacuated. The core of the vacuum framework is the

#### *A Review on Development and Fabrication Methodology for Vacuum Vessel from Aluminum Alloy DOI: http://dx.doi.org/10.5772/intechopen.81083*

vacuum chamber, which is customized to each application. It encloses the application and reliably splits it from the outside or protects the surrounding from the processes inside. A vacuum vessel has numerous isolating ports that are covered with the flanges and this enables instruments or windows to be introduced in the dividers of the vessels.
