TTV Aluminium Bronze Wafer TTV Butterfly ValvesNow Fully WRAS Approved Valve & EPDM Seat TTV Aluminium Bronze Wafer Butterfly Valves with EPDM Seat The TTV Aluminium Bronze Wafer Butterfly Valve is now fully WRAS approved, covering both the EPDM seat and the entire valve assembly. Designed for dependable shut off and flow control, this valve combines a corrosion resistant aluminium bronze disc with a resilient, WRAS certified EPDM seat making it a fully compliant solution for potable water