VPI System Overview

Bradleys’ is equipped with 8 foot and 12 foot diameter VPI tanks and maintains strict quality control standards. Our QC program includes maintaining clean tanks, resin temperature, quarterly resin testing, vacuum pumps and control panel.

Our Vacuum Pressure Impregnation (VPI) System is a better method than the older method of "dip and bake." It is used for many applications ranging from insulations to sealants. VPI provides 100% solid mass structure, and solvent varnishes lose 50% to 70% of volume during baking. According to numerous field audits since 1975, VPI has, for all practical purposes, eliminated field failures caused by voltage tracking*. *EASA, Electrical Apparatus Service Association, Inc.

VPI creates a better product in less time and at a lower cost than other available procedures that try to achieve the same results. With VPI, your motor runs cooler due to superior heat dissipation, has completely upgraded mechanical strength, and environmental protection.

Global VPI: Polyester and Epoxy Resins All in One Shop!
In 2016, Bradleys added the high voltage Epoxy Resin Global VPI. Von Roll Permafil 74050 epoxy resin has both high temperature and Class H insulation properties and complements our existing polyester global VPI resin, Von Permafil 724, which also has high temperature 220C and Class H insulating properties. At Bradleys, customers have a choice based on their electric motor needs.


  • Strengthens the insulation system of your motor and extends service life.
  • Eliminates the dead air spaces that cause hot spots within coils.
  • Provides a low thermal resistance path that lowers temperatures.
  • Creates a repellent to oily substances, moisture, and chemical contaminants.
  • Resin becomes a sealant against environmental conditions and creates bonds for good mechanical strength.
  • Reduces mechanical vibrations.
  • Reduces the audible noise level.
  • Enhances the dielectric capability, which allows for higher voltage stress levels without failure.
  • Reduces coil movement