Spiral wound gaskets is categorized as semi-metallic gasket that is typically used for high pressure applications. The sealing element is formed by winding two materials (one for sealing, one for resilience) into thin v-shaped spirals.
One material used in the sealing element is usually a metal and the other, referred to as a filler, which is a soft nonmetallic material, typically Teflon, aramid fiber or graphite. Both are chosen for compatibility with the sealing media and their ability to withstand the operating conditions. Different configurations exist to handle different flange designs and operating conditions.
These gaskets have good recovery and good tolerance for flange-surface finish irregularities. The sealing action is the result of a combination of the flow of the metal and soft filler plies when the gasket is compressed. They are particularily suited for assemblies subject to extremes in joint relaxation, temperature or pressure cycling, shock, or vibration