DUAL PLATE CHECK VALVES DUAL PLATE CHECK VALVE WaferFlangedSolid LugButt WeldHub Ended Design Standard: BS EN ISO 9001, API 594, BS EN 10204 3.1 Testing Standard: API 6D, API 6FD, API 6FA, BS EN ISO 10497 Applications: LNG, Pipeline, Petrochemical, Offshore, Power, Refinery, FPSO, Chemical & Fertilizers.