by Kat Griffin Kat Griffin

Exploring EDM Water Treatment Systems

In Electrical Discharge Machining (EDM), where thorough flushing is crucial, ensuring the chemical purity of dielectric water is of utmost importance. This exploration delves into the prevalent systems used to uphold the integrity of the dielectric water vital for both Wire and Small Hole EDM processes. Learn the various types of systems used in EDM to maintain the quality of dielectric fluid.


  • Refillable Bottle Systems: In the early stages of Wire EDM, machines often included resin containers tended to by operators. This arduous process involved replacing depleted resin, cleaning containers, and refilling them with loose resin. However, the mess and hassle associated with this method rendered it unpopular. Moreover, disposing of contaminated resin posed environmental concerns.
  • Dual Bed Systems: This setup, comprising separate tanks for anion and cation resin connected in series, was once efficient but gradually fell out of favor due to the inconvenience of managing separate tanks.
  • Mixed Bed Systems: Combining anion and cation resin in a single container, mixed bed systems now dominate EDM water treatment due to their efficacy.
  • Bag Type Mixed Bed Systems: Enclosed cloth bags filled with mixed bed resin offer a convenient solution. When it’s time for resin renewal, the exhausted bag is simply replaced with a new one.
  • Tank Type Mixed Bed Systems: Most contemporary machines utilize fiberglass tanks containing mixed bed ion exchange resin. Once exhausted, these tanks are either regenerated or exchanged for fresh ones.resin tanks
  • Filtration Systems: These systems employ filters to remove contaminants, particles, and debris from the dielectric fluid, ensuring its purity.
  • Ion Exchange Systems: Ion exchange systems use ion exchange resins to remove dissolved ions and impurities from the dielectric fluid, improving its conductivity and overall quality.
  • Reverse Osmosis (RO) Systems: RO systems utilize semipermeable membranes to remove dissolved salts, minerals, and other impurities from the water, producing high-purity water for EDM applications.
  • UV Sterilization Systems: UV sterilization systems use ultraviolet light to disinfect and sterilize the dielectric fluid, eliminating bacteria, algae, and other microorganisms that can degrade its quality.
  • Distillation Systems: Distillation systems heat the dielectric fluid to its boiling point, then collect and condense the vapor to produce purified water, effectively removing contaminants and impurities.
  • Electrodeionization (EDI) Systems: EDI systems combine ion exchange resins with an electric current to continuously remove ions and impurities from the dielectric fluid, producing high-purity water without the need for chemical regeneration.

Resin System Accessories

Two essential accessories enhance the functionality of resin systems:

  • Resin Strainer: Prevents resin beads from contaminating the water system by filtering outlet flow.
  • Conductivity Light: Monitors water conductivity post-deionization, signaling the need for resin replacement before conductivity reaches alarming levels.


In summary, the deionizing system is essential for reliable EDM operation. Removing impurities from the water, ensuring optimal conductivity. Additionally, it safeguards against electrode corrosion, prolonging equipment lifespan. Furthermore, it enhances machining precision, leading to quality machining. Overall, its significance cannot be overstated and maintaining these systems are vital for sustained productivity.

Special thanks to Roger Kern from EDM Today for inspiring this blog post.