Overall dimensions and technical information are provided solely for informative purposes and may be modified without notice 6 Vacuum technology Catalogue Introduction Vacuum technique VACUUM TECHNIQUE “The vacuum is an experimentally attainable state”, as it is defined in physics. By vacuum, we mean a space completely void of matter, “called absolute vacuum”.In practice, this state is unattainable, sowhenwe say vacuum, we mean that the air pressure inside an environment is lower than atmospheric pressure, or when the density of the particles in the air is lower. With the expressions “Vacuum”, “suction”, “negative pressure”, etc., we are referring to a pressure below atmospheric pressure, due to the weight of the overlying air. At sea level, this pressure is equal to 1013 mBar. Degree of Vacuum Depending on whether the pressure is higher or lower than atmospheric pressure, the phenomena that occur can vary considerably, and thus the means of achieving and measuring such pressure also varies. Usually we distinguish between different degrees of vacuum that are referred to by specific names as a function of the various intervals of sub-atmospheric pressure, as indicated below: 1) Low vacuum 2) Medium vacuum 3) High vacuum 4) Ultra high vacuum 5) Extreme high vacuum In the industrial field, the vacuum is subdivided into three areas of application, which depend on the degree of vacuum required: Low vacuum: This term means a degree of vacuum between 0 and -20 KPa inclusive, most often used in applications where high air flow suction is required. In this industrial segment, electromechanical impeller pumps, side channel blowers, vacuum generators etc. Industrial Vacuum: this term refers to a degree of vacuum between -20 and -99 KPa inclusive. This range includes many of the applications where the vacuum is produced mainly by vacuum generators based on the Venturi principle, powered by compressed air and by vacuum pumps of the rotary vane, liquid ring, piston and hook-and-claw types, all driven by electric motors. Process Vacuum: This is a degree of vacuum higher than -99 KPa, where the main generators of this degree of vacuum are the two-stage rotary vane pumps, turbo molecular pumps, diffusion pumps, cryogenic pumps, etc., all driven by electric motor. The highest value of vacuum reached on earth is still far from the value of an absolute vacuum, which remains a purely theoretical matter. Even in space, so therefore in the absence of an atmosphere, there is a small presence of molecules per cubic metre. The impetus to improve vacuum technologies comes from industry and research. There is a great number of practical applications and highly disparate sectors: vacuum is used in the metallurgical, aerospace and food industries, in particle accelerators, in microelectronics, in the glass and ceramics industry, in industrial robotics, in moving and handling with suction cups, etc.