The TTV High Performance Double Offset Butterfly Valves provide a reliable leak tight shut off for some of the most demanding applications. Optional seat materials include the R-PTFE which is recommended for mediums including aggressive chemicals, LPG/LNG, petroleum, ethylene and vacuum with a flexible metal seat available for higher temperature requirements and mediums such as saturated steam, gases, bitumen and thermal oil. The metal seat also complies with BS 6755 part 2 or API 6FA/607 fire safety.