Vacuum pressure impregnation (VPI) is a process used to protect and strengthen porous materials, typically used in electrical equipment, by introducing a protective resin into their internal structure. This process ensures that the material is sealed, preventing moisture or other contaminants from penetrating and causing damage.

The setup for a vacuum pressure impregnation system consists of several components. Firstly, there is the impregnation tank, which is a sealed vessel capable of withstanding vacuum and pressure. The tank is made of boiler steel to withstand high pressure, and its size may vary depending on the size and quantity of materials to be impregnated.

Next, there is a vacuum pump, which creates a vacuum in the impregnation tank. The vacuum eliminates any trapped air or moisture from the porous material, ensuring effective impregnation. The vacuum pump can be an oil-sealed rotary pump or a dry vacuum pump, depending on the specific requirements of the process.