Not all Gylon is the same, and picking the wrong style is a common mistake for buyers who assume it’s a single product rather than a family of materials with genuinely different chemical profiles. PTM stocks and converts a wide range of Gylon styles, and here’s a straightforward look at what actually separates them.
Style 3500, often called Fawn Gylon, is the general purpose workhorse of the range. It handles strong acids with the exception of hydrofluoric acid, along with steam, solvents, hydrocarbons and chlorine, making it a solid default choice for chemical processing lines that don’t have one particular aggressive media dominating the service. Style 3504 trades some of that broad resistance for better handling of moderate concentrations of acids and caustics, hydrocarbons and cryogenics, and it’s supplied with aluminosilicate microspheres that help it resist compression set at low temperatures. Style 3510 sits at the top end of the range for the most aggressive media, where 3500 or 3504 wouldn’t offer enough margin.
Beyond the numbered styles, Gylon Bio-Line is worth knowing about separately if your work touches pharmaceutical or food processing. It’s built to the same restructured PTFE process that gives standard Gylon its resistance to creep and cold flow, but formulated to meet the tighter compliance standards those sectors demand, including FDA and USP class VI requirements. That matters because standard PTFE gasket sheet, while chemically inert, tends to suffer from cold flow under sustained bolt load, gradually losing its seal over time. Gylon’s manufacturing process largely resolves that, which is exactly why it holds bolt tension for longer than unfilled PTFE in the same service.
If your current application runs on a general purpose CNAF gasket and you’re seeing early failure, it’s worth asking whether the chemical exposure has actually outgrown what CNAF can handle. That’s usually the point where Gylon earns its higher price tag. PTM’s full Gylon range covers all the standard styles, and our pharmaceutical and chemical industry pages set out the wider material options for each sector.
If you’re not sure which Gylon style fits your process, our technical team can walk you through it. Email sales@epdm.co.uk or call 01625 573971 and we’ll help you specify the right grade first time.
