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Summer 2010
E-News Release
What's Inside:

Graver Aegis® Classic Yarn Wound Condensate Polishing Precoat Septa

Reducing Cobalt: Introducing Gravex Macroporous Nuclear Grade Resins

Ask Graver

10CFR50 Appendix B 10CFR 21
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POWDEX Premix™

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Granular Activated Carbon

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Graver Aegis® Classic Yarn Wound Condensate Polishing Precoat Septa

How Graver Technologies developed the very best septa for Condensate Polishing (CP) precoat applications.
Graver’s Powdex® technology, in its original invention, was designed with two essential components for efficient operation:
  1. High quality, highly regenerated and kinetically superior Powdex ion exchange precoat material, and
  2. A superior backwashable septa to maintain a uniform precoat on the septa surface. This allows the ion exchange reaction to proceed efficiently and fully remove ionic impurities while also filtering insoluble corrosion products. The septa will also prevent precoat material from “leaking” and entering the polished condensate stream.
How Graver’s Aegis® Septa Function

Graver’s Aegis septa, also referred to as a CP element, may appear to look like a standard string wound filter cartridge but in actuality it’s quite different. In a non CP filter cartridge, dirt is captured throughout the depth of the cartridge with the filter design including a relatively porous surface progressing to the tightest porosity at the inner core. For CP precoat septa, filtration and ionic contaminants need to be captured on the outer surface so that they can be removed easily during the air and backwash cycle without fouling the septa. While the ion exchange precoat material is used for only one operating cycle and then replaced, CP septa are expected to provide service for up to 200 precoat cycles.
Graver's first generation Aegis septa were manufactured using specially selected wound segments with similar characteristics. The segments were then matched and joined to give the overall proper length for the system design. These septa were effective but the process of testing the cartridges and matching the differential pressures was time-consuming and less than perfect. In addition, variations in the thickness of the joined sections could cause variations in overall septa length.
How Graver Technologies Perfected the Yarn Wound Septa
Over the years, Graver Technologies has improved the Aegis Yarn Wound septa to eliminate these issues and substantially improve septa performance. More than 20 years ago Graver Technologies designed proprietary technology that uniformly winds a single septa up to 80 inches long. This eliminates variations in differential pressure along the entire length of the septa. At the same time, Graver Technologies developed a proprietary winding pattern that increased the efficacy of the air and water backwash of the septa by allowing increased velocities across the windings. This new winding configuration also made the septa self-healing if damage occurred to the outer layers. Additionally, Graver Technologies designed various modifications to the one-piece stainless steel core that minimizes compression on the windings from the installation hardware.
Further improvements were made in the 1990s with a next generation technology that enhanced and further standardized the winding process through computer controls. Graver Technologies also certified the manufacturing process into an ISO certified quality assurance program that established requirements for raw material traceability and equipment calibration as well as in process and final product testing.  

Still Indispensable, Still the Best
These important steps and thoughtful, substantial investment coalesced to make the Aegis Yarn Wound CP precoat septa the most thoroughly tested, longest-lived and most dependable precoat septa on the market today. Knowing the facts and history of this extraordinary product prepares you for the question, “Why are you still using wound septa in your precoat systems?” Your confident responses:
  1. “Original equipment manufacturers (OEM’s) overwhelmingly prefer and specify Aegis Yarn Wound Septa for new precoat systems to ensure optimum performance of their equipment. Utilities can rely on the performance of Aegis Septa to meet or exceed all warranty conditions for both impurity removal and life cycles.  
  2. “Graver Technologies has tested and improved the Aegis Yarn Wound septa both in the lab and actual service for over 40 years and it is superior to all other septa in providing a matrix for ion exchange media and preventing precoat bleed through.”
Graver’s improvements in Powdex ion exchange precoat, along with septa design and manufacturing improvements, have allowed CP systems originally designed to remove 90% of the contaminants to operate at much higher removal levels
Contact your local Graver Representative for more information about Aegis Classic Yarn Wound Septa.

Reducing Cobalt: Introducing Gravex® Macroporous Nuclear Grade Resins
The Spring 2010 issue of Powerline discussed colloidal cobalt; many nuclear power customers wish to reduce radiation source term values, and one of the most prevalent source term radionuclides is cobalt. Cobalt and other radioactive species increase manpower exposure, hamper optimized plant operation and raise radwaste remediation and disposal costs.
Graver recently introduced a comprehensive family of products designed to remove fine particulate radionuclides including isotopes of cobalt, nickel, iron and silver. Tailored for reactor coolant treatment applications in the chemical and volume control system, these products are ideal for cleanup after outages to help maintain plant restart schedules and to improve performance during normal operations.
Gravex® anion, cation and mixed bed Macroporous Nuclear Grade Resins have been regenerated and processed to provide the highest possible performance. Products include:
  • GR-1-5 NG (OH) – Nuclear Grade anion macroporous exchange resin
  • GR-2-17 NG (H); GR-7-17 NG (7Li) – Nuclear Grade hydrogen or lithium 7 form cation  
  • GR-3-17 NG (H/OH) – Nuclear Grade 2:1 C:A volume ratio mixed bed
  • GR-4-17 NG (7Li/OH) – Nuclear Grade chemically equivalent mixed bed with lithium 7 form cation
To achieve the most effective performance, a five to ten cubic foot layer of GR-1-5 NG is applied over a 20 to 25 cubic feet of either of the mixed beds. The GR-2-17 NG may also be applied as a layer when circumstances dictate.
Please contact your Graver representative for more information about these innovative products.
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Q. How is an ion exchange precoat best applied to Aegis Septa?

A. One precoats septa by injecting precoat material in a liquid stream through the septa. As the liquid passes through, precoat material deposits on the septa’s surface and the liquid recirculates through the system. Two critical steps ensure a good precoat:
  1. A properly prepared solution of precoat material.
  2. The precoat addition rate.
To assure the first step, use products like Graver Technologies Premix® Resin or Ecodex®, which Graver Technologies specially manufactures to give the proper precoating characteristics including particle size and floc formulation. The precoat injection/cycle time should be 25–40 minutes. Enhance the precoat process by using an Advanced (Constant Feed) Precoat System and/or an internal flow distribution tube. Apply the precoat to the septa in successive dosages; the change in dosage is based on an increase in differential pressure where the precoat is laid down. If the particle size of the precoat is too big or the precoat is applied too fast, the increase in differential pressure will not be adequate to direct the precoat material to all areas of the septa; thin or bare areas will be present and water quality will be less than desired.
Q. When should septa be considered for replacement?

A. The life of a septa is based on the total number of precoats applied to the septa and the type of service. For utility fossil fuel operation, septa should receive 150–200 precoats. For nuclear operation, 50–100 precoats is typical. Elements should be replaced before a problem develops. Normal reasons to inspect and/or replace elements include:
  1. More than 150 precoats for utility fossil fuel operations.
  2. More than 50 precoats for nuclear operations.
  3. Clean (after fresh precoat) differential pressure greater than 7 PSI.
  4. Prolonged operation greater than 180F.
  5. Suspected introduction of manmade organics (oils and lubricants).
  6. Prolonged operation with dissolved oxygen values greater than 50PPB (oxygen in combination with metal will cause breakdown of the yarn).
Your local Graver Technologies representative will happily provide more information on septa precoating procedures or element life
Q. Where can a customer find MSDS and specification sheets on the Graver Technologies website? 

A. All MDSD and product sheets are available on our web site via this link:
Gil Royal
North American Sales Manager
phone: 302-731-3554
cell: 302-668-4163
Mark Koster
President International
phone: 302-731-3513
cell: 302-463-5896
Seth Kaufman
Regional Manager NW/Canada
phone: 704-854-3422
cell: 704-904-5168
Dr. Maurice Rens
Director of European Sales
Stuttgart Office: (49) 711 3154 7160
cell: (32) 49 521 2746
fax: (49) 711 3154 7170
Charlie Mosser
Service Manager
phone: 817-326-3626
cell: 817-233-9358
Erbao Zhang
Country Manager - China
cell: (86) 137 0188 2885
Wayne Norwood
Regional Manager Southeast
phone: 301-953-7731
cell: 301-332-7934
Xu Xiangdong
Regional Manager - China
cell: (86) 139 1058 0025
Doug Round
Regional Manager West
phone: 281-312-3223
cell: 972-365-4598
Bin Cong
Regional Sales Manager - China
phone: (86) 21 5238 6576
cell: (86) 138 1783 3997
Al Tavares
IX Technical/Product Manager
phone: 973-465-2370
cell: 201-787-3696
Maureen Vollinger
Global Customer Service/Inside Sales
phone: 302-731-3516
phone: 800-533-6623
fax: 302-369-8356
Brian Raab
Utility Filter Product Manager
phone: 302-731-3512
cell: 443-907-9113
Dr. Peter Yarnell
Ion Exchange Development Group Leader
phone: 302-731-3529
cell: 302-731-1707
You demand a lot from your ion exchange resins.
You can expect a lot from Graver Technologies.
Graver Technologies | 200 Lake Drive | Glasgow, Delaware 19702 | 800.249.1990 |

© Graver Technologies, 2008.

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