Gravex® is a complete product line of high-purity, quality-certified cation, anion and mixed bed ion exchange resins.

These custom-blended bead resins are the cleanest bead available, washed and classified, every batch tested and samples filed for future reference.

They are processed to meet nuclear specifications. We offer the most conclusive results available for nuclide removal products. Graver Technologies also supplies bead resin manufactured by Dow, Rohm & Haas and Lanxess (Bayer).

These Gravex Nuclear Grade Ion exchange resins are very high capacity polystyrene, gel type resins. They have been regenerated and processed to provide the highest possible performance in nuclear applications. The Gravex cation is specially processed to minimize leachable sulfonic acids.

Its high capacity and oxidative stability help achieve optimal performance. Gravex mixed beds are the most uniformly blended products available and have the same consistent cation to anion ratio in every package. Our unique blending process creates the less separable GR-3-16 NG stoichiometric mixed bed. A 7Li+ form cation is available as GR-7-16 NG and in the GR-4-7 NG mixed bed.

Proven Technology for the Most Challenging Separations

Graver Technologies’ specialty mixed bed resin, Gravex GC-3-1 SC

Stator cooling water is one of the most critical systems in a power generating plant. The copper stator bars are cooled in this closed loop system to prevent overheating and reduced generator performance.

A mixed bed ion exchange polisher continuously treats the recycling water to remove ionic contaminants while providing some filtration of particulates, generally copper oxides.Graver Technologies has the optimum mixed bed product, Gravex GC-3-1 SC, for your stator cooling system.


  • Premium grade mixed bed ion exchange polishing resin
  • High capacity strong acid cation and strong base anion components for longest possible run
  • Only mixed bed product that meets General Electric’s stringent requirements for stator cooling mixed beds, GE spec A50A306, Rev. S-8
  • Specially packaged in durable polyethylene-lined one cubic foot fiber drums

Properties and specifications

Resin Type
Strongly Acidic Cation Exchange Resin
Strongly Basic Anion Exchange Resin
FunctionalitySulfonic Acid
Quaternary Ammonium
Matrix Styrene-Divinylbenzene
Cation: Anion Ratio1:1 Equivalents
Total Exchange Capacity 1.90 meq/mL (Cation H Form) (min)
1.25 meq/mL (Anion OH Form) (min)
Percent of Sites 98% Hydrogen (min)
95% Hydroxide (min)
Water Retention Capacity45 – 51% (Cation H Form)
42 – 49% (Anion Cl Form)
Whole Bead 99.5% (min)

Aegis®DualGuard I® Condensate Polishing Septa

Graver Technologies DualGuard elements are engineered for systems that require a uniform precoat on the outer surface of the septa, providing an effective removal of iron oxide particles while still allowing for an effective backwash.

The all polypropylene constructed element has two distinct zones. The outer zone is a multi-string wound surface ideal for precoating in either a thin or a full layer resin precoat and the inner zone is a pleated polypropylene with a fixed pore media. The inner pleated filter media is available in a variety of micron grades to meet specific requirements of the condensate system. The element is available in most end cap connections.

  • The optimum precoat surface allows for the distribution and sustainability of an evenly thin layer precoat for optimum performance
  • Precoatable with a full or thin layer of powdered resin
  • Available in various outside diameters
  • Fixed pore construction eliminates dirt unloading as differential pressure increases
  • High surface area of pleated media
  • Removal efficiency rated


Graver Technologies, LLC introduces TurboGuard, its technically improved 6 inch (152 mm) high-flow filter for the utility market. Graver is the world’s largest supplier of condensate system filters and components and has been manufacturing precoat and non-precoat septa for condensate systems for more than 50 years. Graver is the consistent technology innovator with more than 40 patents and numerous technical advances for condensate and high purity water applications.

Graver’s family of TurboGuard High Flow Filters will provide superior CRUD removal upstream of deep bed demineralizers. TurboGuard High Flow Filters may also be used following ion exchange beds as a resin trap,
or as highly efficient pre-filters before membrane systems. Graver’s TurboGuard line of filters are manufactured in the USA at Graver Technologies manufacturing plants, under an ISO-9001 (2000) quality system.

Graver’s TurboGuard High Flow Filter integrates a number of improvements over currently available elements. With the most experience of any supplier in condensate applications, Graver can access more than 50 years of experience when improving fundamental filtration in condensate and high purity water applications.

AEGIS® TurboGuard® Pre-Filters

  • Flow is from the inside core to the outer pleats
  • TurboGuard Filters are wrapped in a one-piece extruded outer cage preventing media migration during inside out flow
  • TurboGuard’s one-piece extruded outer cage allows for easier maintenance and removal after use
  • One-piece molded end caps, including molded-in bail for secure handling during installation and removal
  • Quad Seal gasket system to provide maximum sealing surfaces
  • Highest dirt holding capacity – approximately 25 lbs (11.5 Kg) before removal is required
  • Low pressure drop – less than 0.2 bar in service at specified flow rate
  • Optimized media surface area allows full use of installed media area – not blocked off by media “squeezing

Typical Applications

  • Pre-filter for protection of Deep Bed demineralizers
  • Pre-filter for protection of RO membranes
  • Retrofit OEM high flow large geometry filter housings

Power Generation Systems — The Right Septa Choice


Graver Water  has optimized deep bed condensate polishing technologies through the use of proprietary flow distribution enhancements and enhanced collection, to maximize resin utilization. For on-site regenerated systems Graver’s trademarked and proprietary two-vessel SepraEight® regeneration design results in a smaller footprint for regeneration equipment without compromising separation efficiency or optimum regeneration.

Deep bed/mixed bed condensate polishers are the preferred technology for plants using high TDS cooling waters such as seawater, as well as where there is a requirement to operate long term with small condenser leaks or an inability to control excessive air in-leakage.

Both Deep Bed and Precoat type Polishers remove iron, copper, silica and salts, and suspended solids. However, Deep Bed Polishers provide the best method for the removal of high ionic loads due to their large ion exchange capacity. Graver’s Deep Bed Condensate Polishers have been designed to handle service pressures of up to 800psi with inlet distributors and underdrain that operate more efficiently than competitive designs.


Ion exchange resin selection and ratios can be optimized for the particular application and condensate chemistry. For instance when “All Volatile Treatment” (AVT) is used the result is an elevated operating pH (amine level) the resin ratio of choice would be a high cation exchange to anion exchange resin ratio (2:1) when in a neutral pH environment, as would be seen in a boiling water reactor (BWR) a stoichiometric blend of the ion exchange media would be employed. Upon exhaustion, either due to ionic breakthrough or pressure drop, the units are regenerated though a series of backwash, chemical regenerants (either in situ, external or off site) and then returned to service.

When Deep Bed Condensate Polishers are paired with a quality ion exchange resin such as Gravex® Bead Resin, efficient polishing of condensate is easily obtained. When the exchange capacity of the resin is exhausted it can either be sent off-site for regeneration or disposal, or it can be regenerated on-site using Graver’s SepraEight technology.


  • High ionic loading removal
  • Up to 800psi service pressure
  • Up to 50 gpm/sq. ft. flowrate
  • Superior resin regeneration


NANODEX FILTER PAPERS TRACK SYSTEM AND PLANT PERFORMANCE by Monitoring Radionuclide and Corrosion Products

Graver’s patented Nanodex Ion Exchange Filter Papers enable diverse quantitative analyses in the power industry, especially nuclear, to monitor corrosion products, measure activity levels and satisfy fuel warranty requirements.

Nanodex AX 100 anion exchange filter disks contain strongly basic, quaternary ammonium functional sites in the chloride form, which can be converted to the desired ionic form (i.e. hydroxide) as required.

Nanodex CX 200 cation exchange filter disks contain strongly acidic, sulfonic acid functional sites in the hydrogen form. Contact your Graver representative for more information about these innovative filter papers.


  • High performance, specialty hydrophilic paper for a variety of analytical requirements
  • Uniform resin distribution throughout each disk
  • Standard 47mm diameter
  • Highly functionalised, highest ion exchange capacity analytical filter
    disks available
    Filter disks are easily digested by standard analytical methods


  • Excellent hydraulic characteristics
  • Consistent ion exchange capacity and utilization
  • Fit standard bench-top and inline filter holders and housings
  • Single disk used per test
  • Simple to quantify ions removed – X-ray fluorescence or Atomic Absorption


Whether the need is for high purity Gravex® condensate polishing ion exchange resins; the original Aegis® wound, DualGuard® or AFA® pleated filter septa; or the Powdex & Ecodex® families of premium resins, the original and most widely used powdered ion exchange resins, Graver Technologies has the answer for your application.

  • Gravex bead resins for condensate polishing including the lowest residual chloride anion available for treating the most critical operating systems
  • Uniform size Gravex for regenerable deep beds
  • Less separable Gravex for non-regenerable systems
  • Powdex and Ecodex for simultaneous precoat filtration and deionization
  • Aegis precoatable filter septa for Powdex filter demineralizers
  • AFA, the first backwashable pleated filters installed in a condensate pre-filter system
  • DualGuard, combination pleated filter with a precoatable and easily backwashable surface