Asbestos O-ring Gasket for sight glass is also named asbestos cushion or cushion joint, they are made from high pressure compressed asbestos fibre rubber sheets. It is a traditional material for the gauge glass sealing which is a general purpose gasket material suitable for service in hot water, mild acids, alkalines, and inert gases. and resistant to temperatures up to 450 °C and the pressure to 150 bar.
