rfly valves have longer face-to-face dimensions and stronger structure compared with wafer or lug type butterfly valves, for butterfly valves size larger than 24", flanged end is recommended for longer service.Features of Triple Eccentric Butterfly ValvesEccentric Disc DesignMulti-layer Disc Seal StandardFully Meal-to metl Seal OptionalUni-directional FlowWafer Body Type, Lug Type or Flanged TypeApplicable Standards of Triple Eccentric Butterfly ValvesA) Design & Manufacture: API 609, EN 593, MS