Sealing in Piston Valve is due to resilient rings in contact with metallic Piston. Sealing Rings are made from special Graphite material with SS316 insert which can withstand high temperature. Therefore, Piston Valve is soft seated but suitable for high Temperature up to 425°C. Presence of graphite rings ensures excellent lubrication and very low friction when Piston is operated. Sealing is amazingly simple, only two rings in sizes from 15mm to 50mm. Lower valve ring seals the media across the port and upper valve ring seals the media to atmosphere.