... Design standard conform to: MSS SP-67, API609, EN593Connection flange conform to: DIN PN10/16/25, ANSI B16 ... .1, BS4504, ISO PN10/16,JIS B2212/2213, BS 10 Table D, BS 10 Table ETop flange conform to ... : ISO 5211Face to face conform to: API609, ISO5752 series 20, ... than comparable swing check valves.3. Easy to install and maintain.Performance:Nominal Diameter: ...