Types of Ball Valves: Soft Seated vs Metal Seated
Depending on the seat materials of the valve, two types of ball valves are found; Soft Seated and Metal Seated Ball Valves.
Soft, non-metal seated ball valves satisfactorily covers most of the applications. Soft seated ball valves use a thermoplastic material such as PTFE, NBR, etc. However, abrasive media, high pressure and temperature can severely stress the polymeric seals leading to damage. Because of this reason metal-seated ball valves are developed in the 1960s.
Metal seated ball valves use metal as seat material such as stellite, carbide etc. Tight shut-off, no jamming, smooth control, good corrosion and wear resistance, wide temperature range, stability under pressure, etc are the advantages that a metal-seated ball valve provides with its soft-seated counter parts.