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:
- High quality, highly regenerated and kinetically superior Powdex ion exchange precoat material, and
- 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:
- “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.
- “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.
