What Is Vacuum Pressure Impregnation?

Picture of Vacuum Pressure Impregnation

Vacuum Pressure Impregnation (VPI) is a process that uses vacuum and pressure to seal porous materials with varnish or resin. The process is used primarily for high-voltage motors and generators to fill gaps in materials to create a void free insulation in various devices.

Industrial electromechanical equipment is designed for durability to provide reliable function and increased longevity, but age, temperature, and environmental factors can degrade porous metals over time. The process of impregnation seals porous materials with varnish or resin, improving the function and longevity of equipment.

The Vacuum Pressure Impregnation Process

Sloan specializes in vacuum pressure impregnation, which is more effective than traditional dip-and-bake methods and is better suited to high voltage motors and generators. Our basic vacuum pressure impregnation motor repair process comprises several steps.

Preheating
We place the equipment in an oven that heats the equipment and allows moisture to evaporate. This helps the resin better penetrate the material.

Dry Vacuuming
We remove the equipment from the oven and place it into a vacuum chamber, which removes air and any remaining moisture.

Filling
We fill the chamber with resin, coating the part and filling in all the gaps and pores in the piece of equipment.

Wet Vacuuming
We reduce the vacuum levels and hold it for a set period of time.

Pressure
We increase pressure within the chamber using dry air, nitrogen, or other gases. This allows for even deeper penetration of the resin.

Draining
We then vent the pressure, drain the chamber of excess resin, and remove the part.

Curing
Finally, the equipment is placed into an oven to cure the resin.

The Benefits of VPI

In traditional impregnation, varnishes can lose up to 50% of their volume in the curing process. The reduced volume leads to air pockets and gaps, making it more susceptible to damage and wear. The vacuum used in a VPI creates a more solid structure that can withstand:

  • Leaks
  • Cracks
  • Corrosion
  • Moisture

VPI also accommodates longer insulation life and greater heat dissipation. Vacuum pressure impregnation is a more cost-effective solution as it extends the lifetime of products while saving energy.

Why Choose Sloan for VPI Services?

Since 1938, Sloan has provided comprehensive repair and refurbishment services for electromechanical equipment, including motors, pumps, and generators. We serve organizations, industries, and municipalities throughout the Southern California region, including Riverside, Imperial, Orange, and San Diego Counties. Our technical staff is trained to properly provide vacuum pressure impregnation services, ensuring reliability each step of the process, and we are dedicated to finding efficient solutions that will save energy and cut costs.

Sloan is the only company in California’s electromechanical sales and service industry to receive the ISO 9001:2008 certification, which is the world’s highest recognition for meeting standards of excellence in manufacturing and service.

Contact us if you have any questions or would like to schedule an appointment for vacuum pressure impregnation motor repair.

What Is Vacuum Pressure Impregnation? was last modified: December 9th, 2015 by admin