Guardian Coolant Recycling Systems | PRAB
The PRAB Guardian removes free-floating and mechanically dispersed tramp oils to .1% or less, eliminating concerns about wastewater haul-away liabilities.
Health & Safety
The Guardian removes tramp oils and suspended solids from contaminated coolants and controls bacteria, minimizing employee exposure to lubricants that can cause health problems and lead to medical claims.
Low Maintenance
The Guardian coolant recycling system is a turn-key system that is easy to operate for minimized operator involvement and training.
  • Reduce coolant waste up to 90%
  • Reduce haul-away costs
  • Typical payback in 6-9 months
  • Reduce new fluid purchase costs by up to 75%
  • Separated fluid can be sold or recycled

Reduce coolant waste up to 90%.

The effective solution to coolant recycling. The PRAB Guardian™ is a centralized system for recycling used coolants, reducing waste fluids up to 90%, and eliminating concerns about wastewater haul-away liabilities. Typical payback in six to nine months.

These versatile and centralized coolant recycling systems remove tramp oils and suspended solids from contaminated coolant, control bacteria and can adjust fluid concentration for fluid recovery. Each turnkey system is designed for easy installation, quick start-up, and simple, efficient operation- clearly making it the best coolant recycling solution on the market today. For a calculation of just how quickly you will pay this system back, call us for a free ROI estimate.

Advantages of PRAB Guardian Coolant Recycling Systems include:

  • Reduces new fluid purchase costs by up to 75%
  • Reduces hazardous waste disposal costs by up to 90%
  • Typical system payback is 6-9 months
  • Easy operation minimizes operator involvement and training
Performantee |

Optional coolant monitoring and management can maximize coolant savings. Ask about the Guardian with optional AC³ concentration controller, or the Coolant Manager for complete automation of the coolant recycling process.


A fully automated coolant concentration controller, the AC³ will maintain set concentration levels within +/- 0.5% accuracy. The exclusive logic built into the controller allows more or less concentrate to enter the discharge flow of the Guardian system. This comprehensive system provides the necessary intelligence to accurately and automatically inject new concentrate only as needed to maintain optimum ratios and achieve maximum tool life.

Coolant Manager

Control bacteria safely and effectively with the PRAB Coolant Manager, an ozone injection module designed to prevent coolant rancidity. The device, which is the size of a small briefcase, can maintain a sump containing up to 3,000 gallons of coolant. Ozone is the natural choice for coolant bacteria control, eliminating the need for biocide. The Coolant Manager works with all common types of coolant: water, soluble oils, semi synthetic coolants, synthetic coolants, and alkaline cleaners.

  • Process up to 1,500 gallons of coolant per hour; larger capacity systems available
  • Remove tramp oils and reduce new coolant purchases up to 75%
  • Meet tighter coolant clarity tolerances with optional polishing filter
  • Extend tool life and save 25% in new tool purchases with Guardian-clarified coolants
  • Remove free-floating oils to 0.1% or less
  • Continuous overflow prevents rancidity
  • Purge coalescing media of solids and sludge with automatic air sparger
More Table Content to the Right.
Drag to View.
Model Processing Rate Dirty/Clean Tank Capacity Length Width Height
HG250 300 gph 125/125 gal 94″ 48″ 79″
HG400 600 gph 200/200 gal 123″ 55″ 60″
HG600 600 gph 300/300 gal 123″ 67″ 60″
HG800 900 gph 400/400 gal 158″ 64″ 65″
HG1200 900 gph 600/600 gal 168″ 64″ 77″
HG1600 900 gph 800/800 gal 184″ 85″ 85″
HG2000 1500 gph 1,000/1,000 gal 185″ 100″ 78″
HG4000 1500 gph 2,000/2,000 gal 191″ 113″ 82″

The PRAB Guardian Coolant Recycling System removes tramp oils and suspended solids from contaminated coolant, controls bacteria and can adjust fluid concentration for fluid recovery. Typical ROI is 6-9 months, depending on the specifics of your application. Click below to estimate your payback time.

PRAB Guardian Coolant Recycling Systems ROI Calulator |

Introduction to the Guardian and How it Works

The Guardian Works when Other Recycling Systems Fail

Successful coolant filtration requires three components (1) particulate removal, (2) tramp-oil removal, and (3) coolant concentration control. The Guardian™ Coolant Recycling System incorporates all three elements—not just pieces—for maximum coolant life. This combination makes it the most efficient option for centralized recycling of metalworking cutting fluids. If your current process is labor intensive, requires a lot of downtime for sump maintenance, or lacks the capacity to handle all the fluid, it’s time for a change. In this video, see how the PRAB Guardian recycles your spent cutting fluids to significantly decrease coolant spend and eliminate tramp-oil issues.

Why does the PRAB Guardian Coolant Recycling System succeed when other systems fail? Successful recycling requires particulate filtration, tramp oil removal, coolant concentration control, and bacteria elimination. The PRAB Guardian incorporates all of them into a fully automated coolant recycling process that is easy to operate and requires minimal maintenance. Large particulate is removed during per-filtration. This process extends tool life by at least 25% for increased uptime and improved surface finish for improved part quality. Multiple secondary filtration options including Magnetic Separators, Paper Bed Filters, and Centrifuges are available when finer filtration is required. An integrated Tramp Oil Separator removes up to 99% of free floating and lossy emulsifying tramp oil. This process extends coolant life, resulting in 75% savings on coolant purchases. The Guardian removes mechanically dispersed tramp oil through a coalescing media compartment that is self-cleaning. The porous coalesce media is highly efficient offering an optimum ratio of coalescent area in open space to pull the maximum amount of tramp oil from the fluid. PRAB’s weir design guarantees the highest purity of oil for maximum value. The separated oil is gravity discharged off to a customer provided container. PRAB offers a coolant concentrated control package that automatically monitors and controls the concentration of coolant in the Guardian Coolant Recycling System. The coolant manager injects ozone directly into the recycled coolant to help control bacteria, viruses, yeast, molds and other hazards that contribute to dermatitis. It is proven to kill 99% of coolant bacteria and extends coolant life up to 25%. Clean coolant passes through a polishing filter on the way back to the machine to further remove any remaining fine particulates. Acting has the last line of defense. PRAB Guardian Coolant Recycling Systems are proudly made in the USA and delivered documented reduction of new fluid purchases up to 75%. Reduced cutting fluid disposal cost by approximately 90% and typical systems payback within 6 to 9 months. Calculate your ROI at

Product Brochures
Product Brochure: Guardian Coolant Recycling Systems
Product Brochure: Coolant Manager
Product Brochure: Coolant Concentration Control
Product Brochure: Mobile Sump Cleaner
Product Brochure: Sump Cleaner Transport Options

Case Studies
Case Study: Aerospace Components Manufacturer Reduces its Environmental Impact and Cuts New Coolant Purchases by 75%
Case Study: Aerospace Components Manufacturer Turns Its Waste Stream into a Revenue Stream
Case Study: Auto Parts Manufacturer Reduces Coolant Purchase Costs and Eliminates Used Coolant Disposal in First 12 Months
Case Study: Cameron International Improves Profitability, Reduces New Coolant Purchases by Recycling Coolant with Guardian System
Case Study: Cashing in Your Chips
Case Study: Iowa Industrial Hydraulics Reduces Coolant Waste by 90% with Installation of a PRAB Guardian 400

White Paper
White Paper: Avoiding Accidents, Injuries & Illnesses In Metalworking Operations
White Paper: Getting the Most Value from Metal Scrap and Spent Fluids
White Paper: Green Engineering
White Paper: Making Wastewater Compliance Part Of A Profit Strategy
White Paper: Reducing Haul-Away Costs in Metalworking Operations
White Paper: Prioritizing Plant Housekeeping In A Metalworking Operation

Other Downloadable Content
PRAB Fluid Filtration Solutions Product Selection Chart Brochure
PRAB Fluid Filtration Systems and Wastewater Treatment Brochure
PRAB Filtration Spectrum Brochure
PRAB Builds Equipment for the Toughest Jobs in Manufacturing and Metalworking

PRAB completes comprehensive sample testing to establish an accurate understanding of the unique characteristics of your mixed solution and its industrial applications. This test determines the correct centrifuge system design and capacity to optimizes the filtration process within your facility

When you’re ready to get started, contact us or request a material test.

Guardian Coolant Recycling Systems |
To discuss your custom application

Top Content

Blog: Avoiding Accidents & Injuries in the Metalworking Operation

If there is more good news to be shared about the current state of the U.S. workplace, it’s that the rate of accidents and injuries are on a healthy downward trend. However, the costs associated with these workplace injuries continue to rise, providing businesses with more financial headaches than relief. It’s not hard to see how economically devastating workplace […]

January 29, 2019
White Paper: Green Engineering

Green Engineering How to Design More Profit into the Metalworking Operation By Ron Chapman, Systems Sales Manager & Teresa Phillips, Senior Marketing Specialist, PRAB   Introduction The green movement is not a new concept. In fact, the basic principles were well-known throughout Europe in the medieval era. However, it was the Industrial Revolution in Europe that […]

August 9, 2019
White Paper: Prioritizing Plant Housekeeping In A Metalworking Operation

Using Automated Systems to Keep a Shop Clean and Free of Hazards Has a Positive Impact on Profit, Productivity and Purpose     By Mike Hook, Sales & Marketing Director, PRAB       Introduction For workplaces in the United States and many other industrialized countries, “cleanliness is a virtue” is more […]

May 6, 2019