Is Permeation Putting You at Risk?

Fluoropolymer linings or coatings for centrifugal pumps are a great solution for highly corrosive applications. However, simply selecting the right fluoropolymer coating is not enough to ensure that you will get a cost effective product that will perform maintenance-free for years.

The primary mechanism that reduces the life of fluoropolymer coated metal products (such as centrifugal pumps) is permeation. Permeation is the transfer of liquids or gases into and through the fluoropolymer lining.

Permeation rates vary as a function of the fluoropolymer selected and operating conditions. However, ALL fluoropolymers are permeable. When corrosive liquids or gases permeate the lining and reach the metal to fluoropolymer interface they will be released into the atmosphere through gaps between the metal armor and the fluoropolymer lining. To maximize the life of the pump the objective is to minimize the amount of gases that will eventually get through to this interface and to slow down the rate of the permeation process. The only solution to slow down this process is to increase the thickness and the density of the fluoropolymer. Thicker and denser linings slow the permeation process and extend the useful life of the equipment.

Not all fluoropolymer application methods are as effective as others. Magnatex Pumps are fluoropolymer lined using a proprietary molding process called Texel Transfer Compression (TTC). This 1200 psi process yields extremely dense, thick and uniform linings which slows the rate of permeation thus extending the life of the pump. The TTC lining process is more expensive than other methods such as roto lining, but in the long run it greatly reduces MTBF (Meantime Between Failure) thereby enhancing process reliability and profitability.

Download complete technical paper:
Permeation—Its Effects on Teflon® Fluoropolymer Coatings

Still have questions about fluoropolymer lined pumps? Please visit our website or call us at 713-972-8666 or (toll free) 866-MAG-PUMP to speak to a knowledgeable applications engineer.