For much of the 20th century, asbestos was the go-to material for demanding gasket applications. It handled high temperatures, it was cheap, and it was widely available. The problem, as we now know, was the serious and well-documented health risks it carried. Asbestos is now banned, and the sealing industry has moved on considerably.
Non-asbestos gaskets have been the standard replacement for decades, and in many respects, the modern alternatives outperform the material they replaced.
Also referred to as NAF or CNAF gaskets, these are manufactured by compressing fibres with a rubber binder. The fibres used are typically aramid, inorganic or graphite, and the binder is most commonly nitrile, though EPDM and SBR variants are available depending on what the application demands. The finished product is capable of handling temperatures up to 400°C and pressures up to 140 Bar, making non-asbestos gaskets a practical choice for steam, water, chemical and high-pressure environments.
One thing that catches people out is assuming all non-asbestos gaskets are interchangeable. They aren’t. Unlike the old compressed asbestos fibre materials, which were fairly uniform, modern non-asbestos sheeting comes in a wide range of grades, each developed for specific conditions. Using the wrong grade for your operating temperature, pressure, or media can lead to premature failure or, in safety-critical applications, something far more serious.
PTM sources materials from Garlock, Flexitallic, Klinger and Reinz, four of the most respected names in gasket sheeting manufacture. Between them, they cover everything from general purpose grades through to fire safe approved, WRAS approved and FDA compliant materials. Some grades are specifically engineered for alkaline conditions, others for high pressure steam or oxygen service. The range is broad, and knowing which grade fits your application is something our team can help with.
PTM produces standard table gaskets day in, day out, but we’re equally comfortable with bespoke requirements. Using our two oscillating knife CAD/CAM cutting tables, we can nest multiple gaskets from a single sheet, which keeps material waste low and costs down for the customer. If you have drawings or samples to work from, that’s all we need to get started.
If you’re specifying non-asbestos gaskets for the first time, or you’re questioning whether your current grade is right for your application, give us a call on 01625 573971 or email sales@epdm.co.uk.
